Further studies on the androgenic, anti-androgenic, and synandrogenic actions of progestins.

Testosterone increases the activity of specific proteins up to 50-fold in the renal proximal convoluted tubule of the mouse. Several progestins are known to modify these effects by mimicking, inhibiting, or potentiating androgen action. In the present study, a series of C-21 and C-18 progestins were examined for their androgenic actions relative to testosterone by using renal β-glucuronidase and alcohol dehydrogenase activities as end points. These steroids were then examined for anti-androgenic and synandrogenic activities by using a fixed dose of testosterone (0.1 mg/day) and varying amounts of progestins (0.05–1.0-mg/day). The androgenic activity of the progesterone derivatives correlated with 6α-methyl substitution. However, a 17α-hydroxyl group inhibited while a 17α-acetoxy group enhanced the androgenic activity of the Go-substituted steroids. All of the C-18 progestins (norethynodrel, d-norgestrel, and lynestrenol) were mildly androgenic on mouse kidney. Because few steroids were anti-androgenic, no...