Regulation by oestrogen of carnitine palmitoyltransferase in hepatic mitochondria.
Treatment of female rats with ethynyloestradiol decreased both the activity of carnitine palmitoyltransferase and its Ki value for malonyl-CoA compared with pair-fed control rats. In starved rats, carnitine palmitoyltransferase activity and its Ki value for malonyl-CoA were both elevated as expected. Oestrogen treatment had no effect on carnitine palmitoyltransferase activity in the starved state, but the Ki value for malonyl-CoA was substantially decreased by oestrogen. Treatment with a more physiological concentration of ethynyloestradiol (15 micrograms/kg body wt. per day) also produced a decrease in the Ki value for malonyl-CoA. These data suggest that the oestrogen may produce its anti-ketogenic effect by increasing the affinity of carnitine palmitoyltransferase for its physiological inhibitor, malonyl-CoA.
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D007700:Kinetics; D008316:Malonyl Coenzyme A / Q000494:pharmacology; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains
D004997:Ethinyl Estradiol; D008316:Malonyl Coenzyme A; D000217:Acyltransferases; D002334:Carnitine O-Palmitoyltransferase