Physical Manifestations

Obese males also encounter physical mechanisms that may enhance and, thus, further attribute to decreased fecundity and fertility. These problems include hypogo-nadotropic hypogonadism (HH), erectile dysfunction (ED) and sleeping disorders, such as sleep apnea. 26.3.3.1 Hypogonadotropic Hypogonadism HH is a form of secondary hypogonadism in which a problem with the pituitary or hypothalamus gland causes the absence or a decreased function of the male testes. This condition is elicited from a...

Nonenzymatic Epididymal Scavengers

Many molecules with intrinsic radical-scavenging activity exist in the epididymis compartment. I do not intend here to present them in an exhaustive fashion. I only focus on those that are quite classical and those that have been highlighted because they are present in unusual concentrations in this tissue. 5.3.1.1 Glutathione and Thiol-Containing Compounds The tripeptide glutathione (GSH) is generally the most important abundant nonenzymatic scavenger in and outside cells. Its cysteine residue...

Laboratory Application of Chemiluminescent Assays

From the above descriptions, it will be evident that while chemiluminescent probes such as luminol and lucigenin cannot yield specific data on ROS generation by human spermatozoa, they are nevertheless sensitive, semiquantitative indicators of redox activity in these cells and many publications have shown that the chemilumi-nescent activity detected in their presence is inversely related to sperm function and significantly elevated in the cases of male infertility 23, 46-54 . A unique...

Nonenzymatic Protection

Non-enzymatic antioxidative systems consists of co-enzyme Q10 (radical scavenger), dietary vitamins such as vitamins A (P-carotene singlet oxygen quencher), C (ascorbate diverse antioxidant functions) and E (a-tocopherol chain-breaking compound) or other substances such as urate (radical scavenger) or aliphatic polyamines such as spermidine and spermine. Vitamin E is the most efficient compound in the lipid phase 149 . All these substances have in common that they detoxify free radicals 150 ....

Varicocele and Oxidative Stress

Seminal oxidative stress (OS) results from an imbalance between ROS production (superoxide anions, hydrogen peroxide, hydroxyl radical, hydroperoxyl radical, and nitric oxide) and ROS scavenging by seminal antioxidants (superoxide dismutase, glutathione peroxidase, catalase, uric acid, vitamins C and E, and albumin). Seminal OS is believed to be one of the main factors in the pathogenesis of sperm dysfunction and sperm DNA damage in male infertility 40-43 . Spermatozoa are particularly...

DNA Damage and Oxidative Stress

Many theories were proposed to explain the molecular mechanism of sperm DNA damage of spermatozoa these are (a) apoptosis occurring mainly during spermatogenesis 56, 57 with DNA double-strand breaks (DSBs) in spermatozoa arising through an abortive apoptotic pathway 58 (b) ROS 59-61 (c) defective chromatin packaging and (d) DNA fragmentation induced by endogenous endonucleases 62 . Sperm DNA damage may result from various physiological and pathological conditions including advanced age 63 ,...

Measurements

The assessment of very low levels of ROS needs special caution because the probes themselves and any of the products under study may influence cells or cause interference in the measurement techniques. First of all, most of the probes can affect capacitation, even to the point of inhibition, simply because they react with ROS to produce a signal and, at the same time, they remove too much of these same ROS that are essential to trigger capacitation. An example is that of luminol and lucigenin,...

Xanthine Oxidase

Xanthine oxidase catalyzes the oxidation of hypoxanthine to xanthine and uric acid in a reaction that involves a one-electron transfer to oxygen to yield superoxide. The source of xanthine oxidase is not completely clear, but increased cholesterol levels, liver damage, inflammation, and hypoxia may stimulate the release of the enzyme from the liver and other organs into the circulation. This circulating xanthine oxidase binds to endothelial cells to produce superoxide 20 . Endothelial cells...

Oxidative Stress in Diabetes Mellitus Associated ED

Diabetes mellitus is one of the major risk factors for ED. It has been estimated that 50-75 of diabetic men have ED 41 . Compelling data from molecular, cellular, and in vivo animal studies implicate a crucial role for oxidative stress in the development and progression of ED associated with diabetes. Both hyperglycemia and free fatty acids augment ROS production. Penile tissue and blood from diabetic men with ED 42-45 and type 1 diabetic animals 46-53 contain high levels of superoxide....

Oxidative Stress and the Endometriosis

Researches did not report a definitive conclusion about the association between OS and endometriosis. Endometriosis may result in infertility due to mechanical blockage of the sperm-egg union by endometriomata, or adhesions, or pelvic anatomy malformations. Peritoneal fluid of women with endometriosis has been found to be increased in size and contains high concentration of activated macrophages, cytokines, and pros-taglandins. Activated macrophage may be responsible for increased production of...

Detrimental Effects of ROS in Patients with Prostatitis

In patients suffering from prostatitis, a negative association with sperm motility and morphology has repeatedly been shown because this condition is also associated with increased leukocyte infiltration in semen. 109, 110 . Accordingly, significantly increased seminal oxidative stress has been observed in patients with prostatitis categories NIH I, NIH II, NIH IIIA and NIH IV 111, 112 . However, even in prostatitis categories NIH III (chronic abacterial prostatitis) and NIH IIIB...

Oxidative Stress and Female Fertility

ROS play crucial roles in the female reproduction they may act as mediators in hormone signaling, oocyte maturation, ovarian steroidogenesis, ovulation, luteoly-sis, luteal maintenance in pregnancy, implantation, compaction, blastocyst development, germ cell function, and corpus luteum formation 135 . Oocytes and spermatozoa can also experience direct damage, which can lead to impaired fertilization due to an environment of OS in the peritoneal cavity. Many events related to infertility may...

Oxidative Stress in Female Reproductive System and ART Outcomes

Of the patients attending an infertility clinic, 40 have detectable levels of ROS formation in their semen and 25 have levels higher than the normal limits 165 . Men with high levels of ROS may have a lower fertility potential compared to those with low ROS 39, 110 . A reduction in ROS production could significantly improve ART outcome 166 . Oxidative stress can originate from the early steps of ART involving the oocyte, sperm, and embryo, as well as later on in the endometrial environment...

Strategies to Overcome OS in Assisted Reproduction

ROS may originate from the male or female gamete or the embryo or indirectly from the surroundings, which includes the cumulus cells, leucocytes, and culture media. In human IVF ICSI procedures, the clinical pregnancy rates have remained unchanged at 30-40 218 . It is hypothesized that the altered redox state in in vitro conditions may play a role in poor ART outcomes, and controlling OS may improve ART outcomes. Fertilization and embryo development in vivo occur in an environment of low oxygen...

Oxidative Stress and Chronic Bacterial Prostatitis

Bacteria responsible for prostate infection may originate from the urinary tract or can be sexually transmitted 28, 29 . The OS observed during chronic bacterial prostatitis is the result of elevated ROS production and or reduced total antioxidant capacity 20, 30 . Indeed, infecting microorganisms trigger an inflammatory defense reaction in the prostate with a resulting OS due to ROS overproduction 18, 25, 31, 32 . Current or past C. trachomatis infection has also been linked with an increased...

Acetyl Cysteine

-acetyl-cysteine (NAC) is a metabolite of l-cysteine produced within the human body. It helps to synthesize GSH, one of the body's most important and powerful natural antioxidant and detoxification mechanisms. NAC increases GSH levels, subsequently alleviating OS by neutralizing free radicals. GSH is also known to aid in the transport of nutrients to lymphocytes and phagocytes, as well as protect cell membranes. NAC plays a vital role in germ cell survival in human seminiferous tubules....

Age and Oxidative Stress in the Germ Line

Bernard Robaire, Catriona Paul, and Johanna Selvaratnam Abstract There is increasing evidence that the male reproductive system declines with advancing age Studies examining germ cells of older men have raised concerns regarding several aspects of germ cell quality. Increasing paternal age has been linked to genetic diseases (achondroplasia, Apert syndrome, and Marfan syndrome) in the offspring of these fathers the incidence of autism and schizophrenia is also associated with increasing...

Aging and DNA Damage and Repair Relationship to Oxidative Stress

Several studies have been done on the effects of oxidative stress and antioxidants on male germ cells during aging however, there are relatively few studies designed to understand whether how oxidative stress is related to DNA damage in male germ cells in the testes. Under normal conditions, sperm maturing in the epididymis generate low levels of ROS, a process that is thought to be related to capacitation 94 . One of the main sources of ROS is electron leakage from the mitochondria of...

Aging and Male Fertility

In 1912, Weinberg noted that the skeletal disorder achondroplasia was prominent in younger rather than older siblings he was the first to suggest the possible link between paternal age and genetic diseases in offspring 4 . Thus, despite the ability of men to father children well into old age, there appears to be a positive relationship between paternal age and genetic disease in their offspring 50 . Older men have greater difficulties in achieving full-term pregnancy with their partners...

Antioxidants

Antioxidants are naturally occurring or synthetic biomolecules that prevent free radical-induced damage by averting the formation of radicals, scavenging them, or promoting their decomposition in the body. Their neutralizing capabilities reside in their ability to donate an electron to ward off the deleterious effects of the highly reactive radicals or by converting ROS into different, less harmful molecules. There are three main routes of defense antioxidants utilized in combating detrimental...

Biological Effects of Heat Induced Oxidative Stress in Germ Cells

Cellular responses against heat depend on the temperature as well as the duration and frequency of heat stress. In humans, continuous monitoring of scrotal temperature shows that scrotal temperature changes every minute, which makes evaluation of the effect of heat in human testis difficult 23, 24 . This notion is important for understanding of the pathophysiology of disorders of spermatogenesis induced by heat stress (e.g., varicocele, cryptorchidism, and environmental exposure). Testes of...

Clinical Treatment

Various forms of drug therapies against the presence of ROS have been developed as a result of research showing the harmful effect of these biomolecules, the first approach being drugs which can inhibit the formation of ROS 1 . The second is the stimulation of endogenous defense mechanisms because ROS are part of the initial protection against inflammation 1, 11 . The use of antioxidants is regarded as the most logical approach in the clinical intervention to treat the free radical's harmful...

Cocaine

Cocaine promotes oxidation via involvement of the enzymes inducible nitric oxide synthase (iNOS) and xanthine oxidase 39 . Daily intraperitoneal injection of 20 mg kg cocaine in rats shows a significant oxidative stress in basal conditions that may be related to their impaired learning ability 39 , It may probably mean that changes in intensity of LPO processes observed during prenatal cocaine exposure are not directly linked to NO pathway activation. Use of cocaine within 2 years of their...

Concluding Remarks

In spite of the quite often contradictory results from multiple clinical as well as experimental studies regarding cytokines and their effects on sperm structure and function, there is no doubt that various cytokines are involved in the regulation of gonads and sperm function. Cytokines detected in the seminal plasma seem to be mainly associated with the leukocytospermia. Moreover, the cytokines may play a crucial role in perpetuation of oxidative stress in semen, especially during the chronic...

Conclusion

Following more than 70 years of research on the topic, it has now been irrefutably proven that sperm oxidative stress is a common underlying cause of sub-fertility in a large proportion of infertile men. It is hoped that this chapter will make it easier for clinicians to identify and successfully treat sperm oxidative stress, thereby maximising the reproductive potential of their patients before resorting to more complex and expensive treatments such as IVF-ICSI. Lifestyle modifications,...

Conclusions

Conditions such as varicocele, genitourinary tract infection, leukocytospermia, and idiopathic infertility are associated with OS and have the potential of causing male factor infertility. Environmental factors such as smoking and pollution can also lead to elevated levels of ROS and subfertility in males. OS results in in vitro and in vivo clinical complications that may affect male fecundity. High ROS levels impair male fertility through lipid peroxidation, decreased motility, DNA damage, and...

Contents

1 Electromagnetic Radiation and Oxidative Stress Geoffry N. De Iuliis, Bruce V. King, and R. John Aitken 2 Mitochondria as a Source of ROS 3 Cryostorage and Oxidative Stress 4 Sperm Capacitation as an Oxidative 57 Eve de Lamirande and Cristian O'Flaherty 5 Protection of Epididymal Spermatozoa 6 Lipid Peroxidation in Human 119 7 Age and Oxidative Stress in the Germ 131 Bernard Robaire, Catriona Paul, and Johanna Selvaratnam 8 Heat and Oxidative Stress in the Germ 149 9 Cytokines and Oxidative...

Critical Commentary

NAC is an -acetyl derivative of the naturally occurring amino acid l-cysteine 67 . Due to the antioxidant nature of NAC, it is thought that NAC supplementation may improve redox status in idiopathic male infertility and semen parameters. Table 22.3 Quality assessment of oral iV-acetyl-cysteine supplementation 600 mg d + vitamin-minerals4 Placebo Se (200 ig d)A NAC (600 ig d)B Se (200 ig d) + NAC (600 ig d)c Placebo13 26-week intervention + 30-W treatment-free 23-36 t Count A(p 0.009). > 0.1)...

Cytokines and Oxidative Stress in the Germ Line

Monika Fraczek, Anna Czernikiewicz, and Maciej Kurpisz Abstract Cytokines are important mediators of the immunologic response and involved in numerous physiological and pathological processes in the male genital tract. The same cytokines that act as elements of immunomodulation for the male gonad appear in large concentrations in semen in a number of pathological conditions, including autoimmune diseases, spinal cord injury, varicocele, or genital tract infection inflammation. The activated...

Cytokines and Spermatogenesis

Testes are considered to be an immunoprivileged organ due to their tolerance of autoantigens secreted during sexual maturity by reproductive cells. This phenomenon supports spermatogenesis 6 . The mechanisms which protect testes against autoimmune diseases are immunological anatomical blood-testis barrier (BTB) which protects against the antigenic leakage out of germ cells to immunological, intraparenchymal cells and against the transition of antibodies from endothelium to the lumen of...

Detrimental Effects of ROS on Sperm Function

In view of the extraordinary high amount of PUFAs in the sperm plasma membranes and the extremely low concentration of antioxidants available in the male germ cell itself, ROS can trigger serious damage to various sperm functions, including motility or DNA integrity. However, ROS do not deteriorate sperm functions in an isolated manner, because ROS have direct and indirect influence on the whole sperm cell. Therefore, oxidative stress has been established as a major ethiological cause of male...

Diagnostic Application of Chemiluminescence Assays

Chemiluminescent assays provide clinically significant results that correlate with the quality of the ejaculate and the fertilizing potential of the spermatozoa both in vitro and in vivo. This is especially true in patients presenting with poor sperm quality such as in cases of oligozoospermia, or in samples where low-density immature spermatozoa recovered following sperm preparation using a density gradient technique. Defective sperm populations such as those exhibiting presence of excess...

Differential Diagnosis

Differential diagnoses include testicular trauma, tumor, polyorchidism, idiopathic scrotal edema, orchitis, epididymitis, inguinal hernias, haematocele, adrenal hemorrhages, meconium peritonitis, scrotal-periscrotal abscess, hydrocele, varico-cele, appendicitis, acute hydronephrosis, funiculitis, fat necrosis, Henoch-Schonlein purpura, polyarteritis nodosa, and torsion of the testicular appendages 1,31,89, 90 , Patients usually present with hemiscrotal pain which is acute and severe. The...

Discussion

With the advances in technology that revolutionize everyday lifestyles and industrialization all around the world, obesity has become a modern-day global pandemic. Moreover, as obesity is predicted to reach record numbers in the near future and fertility rates continue to plummet, scientists have began to link the two together. They have revealed that as much as half of all fertility problems come from male-factor defects. Many researchers have pointed to the increased adipocyte accumulation to...

DNA Damage

DNA is usually protected from oxidative damage by its condensed form and the antioxidants present in the cytoplasm. After lipid peroxidation, DNA in both the mitochondria and nucleus becomes more susceptible to react with ROS. Sperm DNA damage has been associated with poor sperm parameters, infertility, and poor in vitro fertilization (IVF) outcomes 14 . DNA damage may present as fragmentation, deletions, frameshifts, point mutation, and DNA cross-links, as well as other genetic modifications...

Effects of Heat Stress on the Cell Kinetics of the Germ Cells

Transitions during spermatogenesis from mitotic divisions are accompanied by dynamic transitions in the expression of different networks of cell cycle genes, and they suggest that at least some of this differential gene expression may play key roles in regulating the progression of spermatogenic cells through the process of spermatogenesis 89 . Decreased expression of proliferating nuclear cell antigen (PCNA), which is a marker of DNA synthesis, especially in spermatogonia, has been reported in...

Effects of Leukocytospermia

Among the increasing number of partners experiencing fertility challenges, it has been estimated that the male factor is solely responsible for 30 of the failed fertilization rates 26 . Symptomatic and asymptomatic urinary tract infections which produce leukocytes is a condition frequently observed in infertility clinics 27, 28 . This negative effect on the male's fertilizing potential can be a result of the direct correlation which is found between increased concentrations of leukocytes and...

ENOS Uncoupling

Under physiologic conditions, NOS isoforms synthesize NO, which has a key role in vasodilation, antioxidation, and in mediation of vascular homeostasis. Under pathologic conditions, however, NOS isoforms can transform into prooxidants, generating superoxide rather than NO. This switch, which may involve constitutive eNOS and nNOS as well as the inducible NOS isoform (iNOS), is termed NOS uncoupling. NOS uncoupling refers to both the decreased NO-producing activity of the enzyme as well as its...

Enzymatic Scavengers

Primary antioxidant enzymes work in a tightly associated manner constituting the commonly called antioxidant catalytic triad (Fig. 5.2). SOD (EC 1.15.1.1) recycles the spontaneous formation of superoxide anion and doing so generates H2O2. To adapt H2O2 concentrations precisely, cells rely on three enzymes, GPx (EC 1.11.1.9), catalase (CAT EC 1.11.1.6), and peroxiredoxins (PRDX EC 1.11.1.5). GPx and PRDX activities cover both the intracellular and the extracellular compartments while CAT located...

Evolutionary Features of the Metabolic Strategy of Mammalian Spermatozoa

The enzymatic activities of mammalian spermatozoa have kinetic properties and respond to regulation in a manner that closely resembles those of muscle cells. Although ATP-utilizing enzymes in these two types of cells are very different at a molecular level, they both produce contractile force, an activity to which the cellular metabolism is geared. This suggests that sperm's metabolic machinery is geared towards the maintenance of energy for the contractile work of motility only minor amounts...

Fatty Acids and the Induction of Lipid Peroxidation

So far in this review, the emphasis has been placed on the susceptibility of unsaturated fatty acids to oxidative attack. However, free PUFA may also be a significant cause of oxidative stress in these cells. This suggestion hinges on the ability of free, unesterified PUFA to stimulate ROS generation by sperm mitochondria 42 . In this study, a wide range of free PUFA (arachidonic, linoleic, and docosahexaenoic acids DHAs ) were found to trigger mitochondrial ROS generation by human spermatozoa,...

Future Research and Treatment Approaches

A predominant contributing factor that idiopathic male infertility has been shown to have is the imbalance between OS and the antioxidant-induced scavenging of ROS present in the semen 10, 82 . Numerous factors may negatively influence semen parameters, for example posttesticular damage in the epididymis, abnormal sper-matogenesis, environmental variables, or infection 18 . However, the presence of high concentrations of ROS can add to a damaging effect on the sperm parameters, such as...

General Discussion

We reviewed what is presently known on the positive effects of a mild oxidative stress in sperm activation. All these reports demonstrate that the controlled generation of low amounts of ROS by spermatozoa themselves plays an essential role in the modulation of signal transduction events related to the acquisition of fertilizing ability. We identified main actors involved at the initiation of capacitation (1) the sperm oxidase and NOS as ROS generators (2) Zn2+ and Sg as physiological...

Genitourinary Tract Infection

Genitourinary tract infections may be caused by a number of bacteria, including Escherichia coli, Klebsiella pneumonia, Enterococcus faecalis, Chlamydia trachomatis, and Ureaplasma urealyticum 36 , Genitourinary tract infection may originate in the kidney, bladder, epididymis, prostate, or urethra, and includes diagnoses such as prostatitis, epididymitis, orchitis, pyelonephritis, bacterial cystitis, and urethritis. These types of infections are associated with inflammation and increased...

Germ Stem Cells and Aging

Inevitably, if aging germ stem cells (GSCs) are unable to efficiently prevent, intercept, and repair oxidative damage caused by oxidative stress, they will accumulate cellular damage over the years. The prevention of ROS-mediated damage is mainly dealt with by antioxidants these are reduced in aging spermatozoa 86 . The combined effects of increased ROS production, reduced antioxidant activity, and reduced efficiency of the aging cell's repair mechanisms will result in aging germ cells with...

Heat and Oxidative Stress in the Germ Line

Abstract Spermatogenesis is highly dependent on scrotal temperature. In the testis, germ cells but not somatic cells are vulnerable to heat stress. In response to heat stress, germ cells undergo apoptosis, autophagy, necrosis, and cell cycle arrest these behaviors are different in each testicular component. Heat induces oxidative stress in the testicles in a variety of ways, mainly by lipid peroxidation of the cellular membrane and mitochondria-derived reactive oxygen species (ROS), and...

Heat Induced Apoptosis of the Germ Cells

Germ cell apoptosis plays a pivotal role in normal spermatogenesis and is a highly complex process involving genes for various factors such as the Bcl-2 family, Fas, Fas ligand, and p53. Germ cell apoptosis has been considered to guarantee the quality of gametes 50-52 . Many studies with heat stress models have analyzed germ cell apoptosis with local heating at 43 C. Exposure at 39 C had no significant effect detectable by terminal deoxynucleotidyl transferase (TdT)-mediated dNTP nickend...

Heat Shock Factors and Heat Shock Proteins in the Germ Line Against Heat Stress

Heat-shock response is characterized by the induction of a set of HSPs and is a fundamental response in all organisms to protect themselves from heat attack 103 . The HSP family comprises molecular chaperones that regulate protein folding and degradation under stress conditions to maintain cellular homeostasis and survival. These HSPs are expressed at euthermic body temperatures (approximately 37 C) and are found to have distinct locations and functional properties under conditions of stress....

How to Treat MAGI

MAGI should be treated with antibiotics when noxae influence sperm morphology and or function, cause obstruction of the seminal tract, and express themselves with a proven mono- or multiple glandular involvement. On the other hand, the presence of bacteriospermia or leukocytospermia alone does not necessarily mean that there is a glandular infection, since temporary inflammatory episodes are likely present in the majority of sexually active men 27 . Furthermore, bacteriospermia may simply...

Impact of Sperm Metabolic Strategy on Sperm Motility

The energy metabolism of a cell type should be related to its function. This relation has been termed as the metabolic strategy of the cell. In the case of sperm, the question that may be asked is is sperm's metabolic strategy geared to the series of reactions related to the process of fertilization including motility, or does the maintenance of motility dominate the metabolic strategy of the spermatozoon These questions can be clarified by a close look at the kinetic properties of pyruvate...

In Vivo and In Vitro Antioxidant Treatments

Oral antioxidant supplements may be used to counteract OS and treat male infertility. Studies have shown that antioxidants correlate with improvement in sperm parameters however, in excess, these oral antioxidant supplements may have detrimental effects 83 . As an example, improvement in sperm motility and lower levels of ROS were attributed to vitamin E and selenium oral supplementation 84 . Other antioxidant supplementations that have been proven to be effective in reducing ROS levels include...

Infections Inflammations

Both, male genital tract infections and inflammations are medical conditions that are seriously affecting spermatogenesis and sperm transit during ejaculation in terms of an obstruction of the relevant ducts. Their effects can be seen in clinical findings in cases of oligozoospermia (decreased number of sperm), asthenozoo-spermia (decreased sperm motility) or azoospermia (absence of sperm in the ejaculate) 98, 99 . Moreover, they are also the cause of dysfunctional male accessory glands 59 and...

Influence of Cytokines on Sperm Membrane Properties

An adverse effect of proinflammatory cytokines on sperm membrane properties (e.g., lipid peroxidation) is one of the several mechanisms by which cytokines might interfere with sperm quality. A peroxidation of the membrane structures is considered to be the first measurable destructive effect of ROI overproduction, also connected with infectious inflammation, and due to the high content of polyunsaturated fatty acids (PUFAs) spermatozoa are particularly susceptible to this process. An attack of...

Introduction

This chapter will aim to outline the basic principles of electromagnetic radiation (EMR) and what is known about their interactions with biological systems, and then will discuss some early and the most recent findings of EMR and mobile phone exposure and male fertility. The main intention will be to work towards shedding light on the potential mechanisms of action of this radiation on spermatozoa focusing on oxidative stress as the mediator. In recent times, there has been some controversy...

Introduction Cryopreservation Effects on Sperm Fertility

The spermatozoon, like all cells living under aerobic conditions, constantly faces the oxygen paradox oxygen is required for life, but oxidative metabolism of biological molecules can be potentially toxic due to the formation of reactive oxygen School of Veterinary Medicine, Anatomy, Physiology, and Cell Biology, University of California, Davis, CA, USA e-mail smeyers ucdavis.edu A. Agarwal et al. (eds.), Studies on Men's Health and Fertility, Oxidative Stress 41 in Applied Basic Research and...

Laboratory Presentations 2031 Leukocytospermia

Leukocytes are a normal constituent of the human seminal fluid. However, if the leukocyte concentration exceeds the normal values (1 x 106 mL), sperm dysfunction may be seen 101 . Higher leukocyte concentrations can be seen in ejaculates of men with varicocele, genitourinary tract infection, and those who heavily consume alcohol and smoke tobacco 102 . Male smokers diagnosed with infertility have an increased incidence of OS, which may be due to an increase in leukocyte concentrations by as...

Leukocytes as ROS Producers

Leukocytes frequently appear in ejaculates, even in those from fertile men 27 . The WHO, in the latest edition of the laboratory manual 28 recommended a cut-off value for leukocytospermia, an excessive amount of leukocytes in the ejaculate, of 106 mL. Yet, this cut-off value is not unquestioned, and it has been shown that leukocyte concentrations as low as 4 x 104 mL can inflict damage to sperm functions and the DNA 29-31 . Therefore, several groups 32-36 suggested that the cut-off value for...

Lipid Peroxidation in Human Spermatozoa

Abstract Oxidation of lipids can be a blessing or a curse as far as spermatozoa are concerned. Beatitudes are conferred via the oxidative generation of oxysterols, which then drive sperm capacitation by promoting the removal of cholesterol from the sperm plasma membrane. Conversely, the anathema involves peroxidation of polyunsaturated fatty acids (PUFA) to generate lipid peroxides that have a detrimental effect on spermatozoa, disrupting DNA integrity and limiting their competence for...

Loss of Polyunsaturated Fatty Acids During Sperm Maturation

It has been previously reported that ejaculated spermatozoa show high cell-to-cell variability in life span and, consequently, in their susceptibility toward lipid peroxidation 45 , The concentration of DHA significantly differs in subsets of human spermatozoa at different stages of maturation. Immature germ cells and immature sperm have the highest DHA content, while mature sperm have the lowest. DHA content in mouse sperm obtained from the seminiferous tubules was threefold higher than that...

Lycopene

Lycopene is a naturally synthesized carotenoid-class molecule commonly found in fruits and vegetables. It is particularly useful in the human redox defense mechanisms against free radicals. Lycopene has been reported to have the highest quenching rate constant with singlet oxygen and to have a higher plasma level than that of beta-carotene 58 . Normally, it is found in high concentrations in the testes and seminal vesicles however, decreased levels have been demonstrated in men suffering from...

MAGI Associated with C trachomatis or U urealyticum Infection

Among ultrasound-positive MAGI categories associated to C. trachomatis or urealyticum infection, sperm parameters, leukocyte concentration, and ROS production were similar to the findings described for MAGI caused by other microorganisms (Table 25.5). Nevertheless, it should be pointed out that in presence of C. trachomatis or U. urealyticum infection, patients with PVE have the worst parameters in absolute compared with the other two MAGI categories (prostatitis alone or PV) and...

Male Genital Tract Infections

Specific seminal parameters and chemical components which contribute towards the ejaculate can serve as diagnostic tools in assessing if the accessory sex glands are normally functioning 8 . Diverse irregularities or deviations from the standard reference values of these physical characteristics indicate a possible underlying pathophysiological condition 9 . The response of the genito-urinary tract to the invasion of microorganisms and inflammation is an important component of the immune...

Mammalian GPx Epididymal Coverage

It has been shown that the mammalian epididymis expresses several GPx and, to date, it is the organ in which, although at different levels and in different subterritories, most of the known GPx are expressed, from GPxl to GPx8 6, 8 . Within the GPx multigenic family, four members (GPxl, GPx3, GPx4, and GPx5) are particularly well represented and characterized and are located in the epididymal epithelium, luminal compartment, and spermatozoa. Figure 5.3 presents a diagram of the localization of...

Management 2041 Diagnosis

The diagnosis of OS, DNA damage, and apoptosis in the context of male infertility can be made by focusing on the clinical and laboratory presentations that were proven to be associated with these conditions. Additionally, there are specific tests that can be used to identify whether OS, DNA damage, and apoptosis do actually play a role in a specific case of male infertility 113 . There has been no recommendation to implement these tests in routine clinical practice to date. However, there are...

Measurement of ROS by Chemiluminescence Assay

Herein we describe the details of measurement of ROS in unprocessed, i.e., liquefied seminal ejaculate without any further processing by chemiluminescence assay. (a) Disposable polystyrene tubes with caps (15-mL) (b) Eppendorf pipettes (5-, 10-, 50-, and 1,000-mL) (c) Serological pipettes (1-, 2-mL) (e) Disposable MicroCell slides (f) Dimethyl sulfoxide (DMSO Catalog D8779, Sigma Chemical Co., St. Louis, MO) (g) Luminol (5-amino-2,3 dihydro-1,4 phthalazinedione Catalog A8511, Sigma Chemical...

Measuring ROS Production

While detecting the presence of ROS-producing cells is possible, the direct measurement of in vivo ROS concentrations is challenging due to the fact that ROS are very short-lived 1 . In the field of male reproductive studies, the measurement of OS is quantified only indirectly by the presence of ROS. The quantification of ROS has been promoted as a valuable test to be performed in the assessment of seminal plasma that is to be used for ART as it may be beneficial in predicting end points such...

Methods for the Detection of ROS in Human Sperm Samples

Sharma, Arozia Moazzam, and Ashok Agarwal Abstract Male-factor significantly contributes to infertility in couples of reproductive age. Several studies have shown that oxidative stress (OS) is involved in the pathophysiology of male infertility. It is caused by an imbalance between the formation of reactive oxygen species (ROS) and the ability of the antioxidants to scavenge them. There are several methods to measure seminal ROS in the clinical setting, most notably...

Mitochondria as a Source of ROS in Mammalian Spermatozoa

Abstract The influence of reactive oxygen species (ROS) on sperm function and male fertility is well documented in contrast, the role of the mitochondria in the generation of aberrant oxidative stress is a recent development. The mitochondria, comprised of complex machinery for energy production, are also equally complex in term of oxidative stress with multiple sites of ROS generation and multiple neutralizing enzymatic and nonenzymatic antioxidants. Knockout mouse models of enzymatic...

Mitochondrial Electron Transport

Mitochondria generate ROS during normal oxidative phosphorylation and ATP synthesis through electron leak 25 . ROS production by the organelle, however, can be enhanced in response to numerous stimuli or alterations in the cellular environment, resulting in pathologic consequences. Studies performed by Brownlee and coworker 26 suggest that hyperglycemia-induced oxidative stress from mitochondria is the earliest event in the development of diabetic vascular complications. However, in part...

Models of Germ Cell Aging 741 Mouse Models

To examine the mechanisms of aging, several inbred strains of mice, such as the senescence-accelerated mouse (SAM) 66 , and transgenic mouse models, such as Klotho 67 , or mice having null mutations or overexpresssing several enzymes associated with oxidative stress 48 have been developed. There are at least fourteen strains of senescence-prone inbred strains (SAMP) and four senescence-resistance strains (SAMR) the SAMP life span is 40 shorter than SAMR. Interestingly, SAMP1 mice have an early...

Modulators of ROS Generation

Up to date, the formation of both O2'- and NO' increases with capacitation whether induced with BSA, progesterone, ultrafiltrates from biological fluids (FCSu, FFu), etc. 40, 46, 55, 56 However, this does not point out to a specific substance as initiator of ROS synthesis. The cell-permeant analog of cAMP, dbcAMP, stimulates NO', but not O2'-, synthesis 46 , presenting cAMP as a possible intracellular modulator of NO' synthesis 46, 56 . A major factor for sperm ROS generation is naturally the...

Neurogenic ED

Neurogenic ED results from defects in neurotransmission of the smooth muscle response of the penis. It may arise due to trauma to nerves of the brain and spinal cord supplying the penis. Neurological conditions include, but are not limited to, Parkinson's disease, Alzheimer's disease, stroke, multiple sclerosis, spinal cord Fig. 28.2 ED is predominantly a vascular disease. A variety of chronic conditions that involve vascular disorders are associated with impairment of penile vascular function...

Origin of ROS in Semen

In an ejaculate, there are two major sources of ROS, namely, leukocytes and the male germ cells themselves. Leukocytes physiologically generate high amounts of ROS, since this process plays a major role in infections, inflammations and cellular defence mechanisms to kill pathogens. If activated, leukocyte ROS generation can be up to 1,000-times higher than that of spermatozoa 9, 13 . In addition, ROS and oxidative stress in semen can also be caused by numerous other factors (for review see 14,...

Origin of ROS in Semen and Sperm

Reduced forms of oxygen, collectively termed ROS, interact with various types of molecules and include free radicals that are charged molecules with unpaired electrons. Examples of free radicals are superoxide anion (O- ) and hydroxyl radical ( OH) . Not all ROS are free radicals, however, and molecules such as hydrogen peroxide (H2O2), ozone, and singlet oxygen are also ROS and contribute to oxidative physiology and pathology 60, 61 . Within an ejaculate, there are two potential sources of ROS...

Oxidative Metabolism

The existence of oxidative metabolism in human sperm has long been established 2, 19 , It has also been shown that oxidative phosphorylation can support sperm motility in the absence of glycolysis 20 . However, given the idiosyncrasy of sperm, oxidative metabolism in human spermatozoa is less effective than glycolysis in maintaining intracellular levels of ATP along the length of the flagellum and in supporting sperm motility. The inability of oxidative metabolism to generate high levels of ATP...

Oxidative Stress and Infection

Enzo Vicari, Sandro La Vignera, and Aldo E. Calogero Abstract Male accessory gland infections (MAGI) are included among the conventional diagnostic categories recognized to cause male infertility. They constitute a clinical model of oxidative stress for a number of considerations (a) some uropathogens or etiological agents of sexually transmitted diseases (Chlamydia trachomatis, Ureaplasma urealyticum) by themselves, microbial products, and or toxic metabolites may contribute to an...

Oxidative Stress and MAGI

MAGI are a consequence of microorganism canalicular spreading via urethra, prostate gland, seminal vesicles, deferent duct, epididymis, and testis. Hematogenous infections are rare. In the diagnostic workup of MAGI, sperm analysis is viewed as a fundamental step. Indeed, MAGI is diagnosed in the presence of one or more sperm parameter abnormalities (OAT) associated with a combination of two or more of the following factors (Fig. 25.1) Factor A history positive for urinary tract infections and...

Oxidative Stress and Ovarian Function

Different levels of ROS were detected in the follicular fluid environment that may interfere with folliculogenesis and steroidogenesis 139, 140 . Folliculogenesis refers to the maturation of the ovarian follicle, a densely packed shell of somatic cells that contains an immature oocyte. The production of cytokines, kinins, prosta-glandins, proteolytic enzymes, nitric oxide, and steroids before last stage of oocyte production enhances the flow of blood to the ovary 141 . Low intrafollicular...

Oxidative Stress and Sperm Egg Binding and Fusion

The ability of human spermatozoa to bind to zona pellucida is enhanced by low levels of ROS 112 . Moreover, addition of NO--releasing compounds to capacitating medium increased the number of spermatozoa bound to the hemizona 113 . Also, production of low levels of hydrogen peroxides by spermatozoa plays a role in the signaling events controlling capacitation and sperm-oocytes fusion 109, 114 . On the contrary, studies revealed that elevated ROS concentrations are associated with poor...

Oxidative Stress DNA Damage and Protamines

The molecular structure of the human protamine-DNA complex is still poorly understood 48-51 . Most of the models proposed to date are a mere approximation of the actual structure. There is general consensus that the sperm chromatin responds differentially to stressing factors. The reason for this differential response still belongs to the field of speculation. One of the explanations for this differential sensitivity could be related to the fact that the protamines facilitate an efficient...

Oxidative Stress in Aging Associated ED

ED is highly associated with aging, with prevalence increasing from 6.5 in men aged 20-39 years to 77.5 in those 75 years and older, and it is projected to affect 322 million men worldwide by 2025 12, 36 . Oxidative stress is an important factor contributing to ED associated with aging. Endothelial and smooth muscle cells of the aged rat penis produce ROS 37-40 . The sources and mechanisms responsible for ROS formation in the aged penis remain mostly unknown. It has recently been demonstrated...

Oxidative Stress in Sickle Cell Disease Associated Priapism

SCD is a hemoglobinopathy resulting from the expression of abnormal sickle hemoglobin (HbS), which leads to red blood cell rigidity. Abnormal red blood cells are associated with poor blood flow resulting in tissue hypoxia and ischemia 98 . In addition to hemoglobinopathy and red blood cell sickling, SCD features an independent spectrum of vascular dysfunction, involving abnormalities in NO bioavailability, enhanced responses to vasoconstrictors, and elevated oxidative stress 99, 100 . Priapism...

Oxidative Stress in the Seminiferous Tubules and Epididymis

As previously indicated, oxygen radical-induced DNA damage may take place in germ cells during the process of spermatogenesis leading to sperm DNA fragmentation and telomere damage. This may be the result of either an increase in oxygen radical production, a decrease in the expression of antioxidant enzymes or both. Although in most mammalian species the process of spermatogenesis results in the release of mature sperm into the seminiferous tubules, in some species, including the human, a...

Oxidative Stress Theory of Aging

The free radical theory of aging was first proposed by Harman 12 . This theory essentially implies that biological aging is a result of the production of increased levels of ROS. The theory maintains that the normal respiratory chain function of the mitochondria results in sustained ROS production throughout an organism's life span, resulting in an accumulation of ROS-induced damage 12 . It has been proposed that ROS of mitochondrial origin, when produced consistently over time, can cause...

Poly ADPRibose Polymerase 1231 PARP Structure and Function

Sperm DNA integrity is critical for successful embryo development and the transmission of intact genetic material to the offspring 2 . During spermatogenesis, protection of the sperm DNA is achieved by tight packaging into a condensed chromatin. Incomplete chromatin condensation and persistence of DNA strand breaks during spermatogenesis are associated with DNA damage and male infertility 65 , PARP, a DNA damage repair enzyme, has been first introduced by Chambon et al. in 1963. It is...

Propagation of Per oxidative Damage with Transition Metals

The presence of redox-active metals such as iron and copper in sperm suspensions leads to the breakdown of lipid peroxides to form peroxyl (ROO') and alkoxyl (RO') radicals, according to the following equations lipid hydroperoxide + Fe2+ alkoxyl radical + OH- + Fe3+ lipid hydroperoxide + Fe3+ peroxyl radical + H + + Fe2+ In order to stabilize these lipid radicals, abstraction of a hydrogen atom from an adjacent carbon takes place, generating the corresponding acid (ROOH) or alcohol (ROH)....

References

Stephen E, Chandra A (1998) Updated projection of infertility in the United States 1995 2025. Fertil Steril 70 30-34 2. Bhasin S, de Kretser DM, Baker HW (1994) Clinical review 64 pathophysiology and natural history of male infertility. J Clin Endocrinol Metab 79 1525-1529 3. Pasqualotto FF, Sharma RK, Nelson DR, Thomas AJ, Agarwal A (2000) Relationship between oxidative stress, semen characteristics, and clinical diagnosis in men undergoing infertility investigation. Fertil Steril 73 459-464...

Repertoire of Cytokines in Seminal Plasma

In the male gonad, cytokines are produced physiologically and are involved in the normal function of the organ 30, 49, 50 . In this respect, they must also appear as natural components of seminal plasma 51 . A network of cytokines, chemokines, and growth factors, such as interleukins (ILs), IL-1a and -1b, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-11, IL-12, IL-13, IL-17, and IL-18, their soluble receptors and antagonists (e.g., IL-1RA, sR IL-2, sR IL-6), TNF-a, transforming growth factor...

Reproductive Sytems Defense Mechanisms

In examining the negative effects of high concentrations of ROS and the resultant OS, it must be considered that a degree of protection is provided to the spermatozoa by antioxidant defense mechanisms 44, 75 . Due to the proven relationship existing between increased incidents of infertility and inept antioxidant functioning in the seminal plasma 48, 76 , determining the concentration of antioxidants may allow for the assessment of the fertility capabilities 31 . The properties of antioxidants...

Role of Oxidative Stress and Inflammation in the Pathogenesis of BPH

Inflammation is a complex phenomenon consisting of humoral (cytokines) and cellular (leukocytes) components. Inflammation can influence the tissue microenvironment through the production of free radicals, COX activity, and NO synthesis, all linked to the deleterious oxidative effect of inflammation on prostatic tissue. These factors can alter protein structure and function, induce gene changes, cause post-translational modifications, including those involved in DNA repair and apoptotic...

ROS and Semen Quality

Abstract Infertility affects an estimate of 50-80 x106 ( 7-15 of men at reproductive age) men globally and annually. Among these men, a large number of patients (25-40 ) suffer from male genital tract infection inflammation, conditions where reactive oxygen species (ROS) and oxidative stress in the semen play prominent roles in the pathogenesis of infertility. Considering the extraordinary high amount of polyunsaturated fatty acids present in the plasma membrane, spermatozoa are exceptionally...

ROS Are Generated by Osmotic Stress During Cryopreservation

Several steps in a typical cryopreservation protocol are responsible for the osmotic stress that cells experience. First, during the loading of cells with cryopreservative agent (CPA), they typically experience a hyperosmotic stress and shrink on initial exposure to 1 M glycerol. This initial and immediate response is linear (an ideal osmometer) and occurs by passive membrane diffusion in which water travels down its concentration gradient and requires no cellular control. This adjustment in...

ROSGenerating Enzymes in Human Sperm Capacitation NOS and Oxidase One or Two Enzymes

The three isoforms of NOS (epithelial, neuronal, and inducible) are found in spermatozoa both in the head and flagellum (immunoblotting and immunocytochemis-try data) 30, 31, 66 . The oxidase responsible for sperm O.'- generation during capacitation is, however, still elusive. It should be at the membrane level because O2'- is released in the extracellular milieu and SOD (cell impermeant) prevents capacitation 55 . The first consideration given to the possibility that the sperm enzyme is of the...

Sensitivity of Spermatozoa to Oxidative Damage

They are not only the smallest but also the most polarized cells in the body that fulfil their functions even outside the body in a different individual, the female genital tract. To maintain this extreme polarization, spermatozoa exhibit a specially composed plasma membrane containing an extraordinary amount of polyunsaturated fatty acids (PUFA) 46, 47 . This high PUFA content is essential for normal sperm function, as it is the foundation for the sperm...

Signal Transduction Cascades and Phosphorylation Events

Protein Tyr phosphorylation increases during sperm capacitation, from about 2 h of incubation, and is often considered as a marker for this process 2, 17, 39, 44, 103, 104 . However, over the years, we described several transduction cascades forming a tightly regulated network of phosphorylation events, all regulated by ROS, that occur as earlier steps and are prerequisites for capacitation. Soon after the onset of capacitation, there is a rise in cAMP levels 1, 2, 39, 43, 105, 106 both...

Targets at the Molecular Level

ROS are known to interact with all cellular components 19 and we are used to think of lipid and DNA as first targets for ROS in spermatozoa 143, 144 . However, O2'- and NO' have relatively low reactivity and, especially at the low levels they are generated, do not promote lipid peroxidation or oxidation of DNA bases as the toxic hydroxyl radical 19, 20 . As noted above, ONOO-, which is also very reactive, is endogenously formed during capacitation and causes Tyr nitration of sperm proteins 46 ....

The Chemical Principles Underpinning Chemiluminescence

The two major probes that have been used to assess ROS generation by human spermatozoa are luminol (5 amino-2,3-dihydro-1,4-phthalazinedione) and lucigenin (10,10'-dimethyl-9,9'-biacridinium dinitrate). Because lucigenin carries a positive ionic charge, it is generally thought to be membrane-impermeant and to respond to ROS, particularly superoxide (O2-0 anion in the extracellular space. In contrast, the uncharged luminol is thought to be relatively membrane-permeant and to react with a variety...

The Positive Impact of Lipid Peroxidation The Induction of Sperm Capacitation

We have known since the excellent studies published by Claude Gagnon and Eve de Lamirande in the early 1990s that sperm capacitation is an oxidative process that is heavily dependent on the active generation of ROS 9 . While several independent laboratories have confirmed the oxidative drive to capacitation 10-12 , the way in which changes in the redox status of human spermatozoa allows these cells to attain a capacitated state has remained largely unresolved. To date, there is evidence that...

The Significance ofLeukocyte Contamination

When it comes to the measurement of cellular ROS generation, human semen presents some significant problems that might not be encountered in other biological materials. Thus, one of the major drawbacks encountered in analyzing human semen from a ROS perspective is the presence of relatively high levels of leukocyte contamination. Every human semen sample is contaminated with leukocytes, the median concentration being around 24,900 mL or 91,000 ejaculate 18 . Although this may not seem like a...

Therapeutic Strategies to Scavenge ROS in the Penis

The effect of antioxidants on ED was evaluated in several diseased animal models. Gene transfer of SOD in aged animals was found to reduce superoxide anion formation and normalize erectile function 37 . Several antioxidants, such as SOD, vitamin E, ascorbic acid, melatonin, alpha-lipoic acid and gamma-linolenic acid, and per-oxynitrite decomposition catalyst, were found to partially or completely improve diabetic vasculopathy and autonomic neuropathy in the penis and erectile function 46, 48,...