Metabolic clearance rates of androgens and oestrogens in ageing women.
Using the constant infusion technique we have measured the metabolic clearance rates (MCR) for delta 4-androstenedione (A), testosterone (T), oestrone (E1) and oestradiol (E2) in a large group of post-menopausal women. Their mean +/- SE age was 64.5 +/- 1.6 yr, their ages ranged from 46-90 yr. When the MCRs for each steroid were related to age by linear regression analysis no significant correlation was found for any of the steroids. Similarly, when the women were grouped according to their age by decade, the mean MCR for each steroid showed no trend with increasing age. There was no difference in the MCRs for A, T and E1 of the post-menopausal women and a large group of pre-menopausal women. However, there was a significant decrease in the mean MCR for E2 between the two groups which is probably related to the marked decrease in circulating E2 in post-menopausal women. We conclude that for these steroids age, per se, does not appear to be a major determinant of the MCR.
D000328:Adult; D000368:Aged; D000375:Aging; D000735:Androstenedione / Q000097:blood / Q000378:metabolism*; D004958:Estradiol / Q000097:blood / Q000378:metabolism*; D004970:Estrone / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008593:Menopause; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D013739:Testosterone / Q000097:blood / Q000378:metabolism*
D004970:Estrone; D013739:Testosterone; D000735:Androstenedione; D004958:Estradiol