title: Change in the relative importance of oestrone and oestradiol synthesis by the rat ovary between fetal and prepubertal stages.
abstract: Ovaries of rat fetuses at 20 and 21 days and of neonatal rats at 5 and 14 days were cultured in the presence of [3H]testosterone, and the conversion percentages into oestrone (E1) and oestradiol (E2) were determined by double isotopic dilution combined with recrystallization to constant specific activity. Insignificant in the 20- or 21-day-old fetus, oestradiol synthesis increased relative to oestrone synthesis in the 5-day-old neonate (E1/E2 = 3.4) and still more at the stage of 14 days (E1/E2 = 0.78). FSH had no effect on oestrogen synthesis at the 4 stages investigated.
mesh_terms: D000818:Animals; D004958:Estradiol / Q000096:biosynthesis*; D004970:Estrone / Q000096:biosynthesis*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D010053:Ovary / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004970:Estrone; D004958:Estradiol; D005640:Follicle Stimulating Hormone