Androgenic, anabolic, estrogenic and antiestrogenic effects of desogestrel and lynestrenol: effects on serum proteins and vaginal cytology.

Eight healthy (apart from pelvic endometriosis) women were given daily doses of 0.125, 0.250 and 0.500 mg of desogestrel or 5 mg of lynestrenol orally in a randomized order. Duration of each treatment was 6 weeks. Serum was analyzed for sex hormone binding globulin (SHBG), ceruloplasmin, cortisol binding globulin (CBG), thyroxine binding globulin (TBG) and prealbumin using an electroimmunoassay. Serum 17 beta-estradiol (E2) and testosterone (T) were analyzed by radioimmunoassay. Vaginal cytology was studied using the maturation value (MV). E2 levels were depressed by desogestrel and lynestrenol apart from values in two women after 0.125 mg desogestrel. T concentration was suppressed by desogestrel but not by lynestrenol. SHBG concentration and MV were dose-dependently suppressed indicating an antiestrogenic or possibly androgenic effect of desogestrel and lynestrenol. No androgenic or anabolic effects of desogestrel were however seen, e.g. suppression of TBG content or increase in prealbumin levels. For lynestrenol, however, a small but significant increase in prealbumin concentration indicated a weak androgenic/anabolic effect. No estrogenic effects were seen, e.g. increases in ceruloplasmin, CBG levels or in elevations of MV. A depressed SHBG production ability in the hepatocytes during treatment with 19-nortestosterone derivatives is postulated, possibly due to competitive receptor binding.