Effect of estradiol and progesterone on long chain fatty acyl-coenzyme A levels in the rat uterus.
Fatty acyl-CoAs are potential in vivo inactivators of glucose-6-phosphate dehydrogenase (G6PD). Ovariectomized mature rats (n = 74) were given 5 micrograms of estradiol intravenously, then killed 0, 24, 36, 48 and 72 h later. Control levels of myristoyl-, palmitoyl-, stearoyl-, arachidonoyl-, oleoyl- and linoleoyl-CoA were 0.6, 3.2, 4.7, 3.4, 2.4 and 3.0 micrograms/uterus and were increased 39, 110, 146, 100, 84 and 69% at 36-48 h, respectively. Levels of fatty acyl-CoAs in the rat uterus become elevated 36 h after estradiol treatment. At the same time G6PD changes from a stable enzyme to one that is irreversibly inactivated, possibly due to being rapidly degraded. Progesterone (2 mg subcutaneously every 12 h, n = 30), administered beginning at either 24 or 36 h after estradiol treatment, had no effect on estradiol-induced changes in myristoyl-, palmitoyl-, or stearoyl-CoA. Compared to the groups of rats treated with estradiol alone, animals treated with combinations of estradiol and progesterone exhibited higher levels of arachidonoyl-CoA after 48 h, and oleoyl-CoA and linoleoyl-CoA were greater after 72 h. Progesterone increased the estradiol-induced levels of unsaturated fatty acyl-CoAs suggesting that progesterone may induce uterine fatty acid desaturase activity and/or uptake of dietary fatty acids. Addition of fatty acyl-CoAs, at concentrations seen in vivo at 36-48 h after estradiol, to purified G6PD, causes irreversible G6PD inactivation.
Young
A J
AJ
Department of Biochemistry and Molecular Biology, Texas Tech Health Sciences Center, Lubbock 79430.
Barker
K L
KL
D000214:Acyl Coenzyme A / Q000378:metabolism*; D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors; D007700:Kinetics; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014599:Uterus / Q000187:drug effects / Q000378:metabolism*
D000214:Acyl Coenzyme A; C026563:arachidonyl-coenzyme A; C017585:oleoyl-coenzyme A; D010171:Palmitoyl Coenzyme A; C017725:stearoyl-coenzyme A; C026562:linoleoyl-coenzyme A; D011374:Progesterone; D004958:Estradiol; D005954:Glucosephosphate Dehydrogenase