Lipid metabolic studies in oophorectomized women. Effects of three different progestogens.

Ten oophorectomized women (ranging in age from 27 to 45 years, having a mean age of 34.5 years with a standard deviation of 5.3) were given three different progestogens (norgestrel, norethisterone and medroxyprogesterone) in treatment periods of 3 weeks' duration immediately preceded by 3 weeks "wash out" periods. Venous blood samples were drawn before and after each treatment period. Free and total cholesterol, triglycerides and phospholipids were determined in the three lipoprotein fractions: Very low density lipoproteins (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL). Individual phosphatides were determined after thin layer chromatography. In addition, the relative fatty acid composition of serum lecithin and cholesterol esters were assessed by gas-liquid-chromatography. Both norethisterone and norgestrel caused a decrease in alpha-lipoprotein cholesterol. The relative fatty acid composition of serum lecithin revealed an increase of biochemical pathway 1 for liver lecithin synthesis on norgestrel and norethisterone but no major changes on medroxyprogesterone. With norgestrel an increase in serum-lysolecithin concomitant with a decrease in lecithin was observed, while the two other progestogens did not induce any significant changes. From the present data it is suggested that the 19-norethisterone derivatives, norethisterone and especially norgestrel, have androgen-like influences on lipid metabolism. Medroxyprogesterone, being a 17-alpha-hydroxyprogesterone, caused less changes and consequently less disturbance of lipid metabolism.