[In vitro metabolism of (6,7-H3)estrone and of (6,7-H3) estradiol by the liver in pregnant guinea pigs].
Slices of pregnant guinea pig liver were incubated with (6,7-3H)estrone and with (6,7-3H)estradiol. Free, glucuro- and sulfo-conjugated fractions were isolated by specific extraction and hydrolysis. The radioactivity distribution in these 3 fractions demonstrated a predominance of conjugated compounds (95% of isolated estrogens) with slightly more glucuro-conjugated than sulfo-conjugated compounds. After isolating estrogens by TLC, we were able to determine estrone and estradiol in these 3 fractions from incubations with 3H-estrone or with 3H-estradiol by means of specific activity recrystallisation. Estriol was determined in glucuro-and sulfo-conjugated fractions after incubation with 3H-estrone as well as in sulfo-conjugated fraction after incubation with 3H-estradiol. Glucuro- or sulfo-conjugated estrone was the predominant estrogen after incubation with 3H-estrone just as after incubation with 3H-estradiol. This led us to conclude to an important 17beta-hydroxysteroid-dehydrogenase activity. The 16alpha-hydroxylastic-activity is weaker since estriol represented only 1,43 % of estrogens isolated after incubation with 3H-estrone and 0.82% after incubation with 3H-estradiol.
D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D004958:Estradiol / Q000378:metabolism*; D004970:Estrone / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal
D004970:Estrone; D004958:Estradiol; D006899:Mixed Function Oxygenases; D015067:17-Hydroxysteroid Dehydrogenases
Métabolisme, in vitro, de la (6,7-3H)estrone et du (6,7-3H)estradiol par le foie de cobaye gestant.