Bioassay

While immunological methods measure the mass of circulating testosterone, the overall androgenic bioactivity in serum and peripheral tissues results frombioavail-able testosterone and other androgens. An in vitro androgen bioassay has been recently developed, based on the androgen-dependent interaction between the ligand-binding domain and the N-terminal region of the androgen receptor, which were fused to Gal4 DNA-binding domain of Saccharomyces cerevisiae and to the transcriptional activation domain of herpes simplex VP16 protein, respectively. These plasmids are transfected in COS-1 cells together with the coexpression of AR-interacting protein 3, which amplifies the interaction, and with the reporter plasmid containing five Gal4-binding sites upstream of the luciferase gene. Luciferase activity measured in cell lysates results from androgen bioactivity in serum added to the cell cultures (Raivio etal. 2001). This bioassay has a sensitivity of 0.8 nM testosterone equivalents and correlates significantly with total testosterone and free testosterone index. In addition, the bioassay measures androgen levels three to four times lower than total serum testosterone measured by RIA, suggesting that only free and albumin-bound testosterone, i.e. bioavailable testosterone, are detected as bioactive. The use of this novel bioassay is as yet limited to the experimental field (Raivio etal. 2002; Raivio etal. 2003a and b).

Using Exercise To Get Rid Of Man Boobs

Using Exercise To Get Rid Of Man Boobs

In this guide, youll learn just what kinds of exercises you can use to get rid of man boobs forever. It includes two different types of exercises those designed to burn body fat, helping you lose excess weight all over your body and targeted chest exercises which will shrink your man boobs until you have a masculine, sexy chest.

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