Action of insulin on liver carbamoyl-phosphate synthetase II (glutamine-hydrolyzing) activity.
Carbamoyl-phosphate synthetase II (glutamine-hydrolyzing) (EC 6.3.5.5) (synthetase II), is the first and rate-limiting enzyme in the de novo UMP biosynthetic pathway. The present investigation showed that insulin has a regulatory action on hepatic synthetase II activity. When diabetes was induced with injection of different doses of alloxan the plasma insulin concentrations decreased in a dose-dependent fashion to 72, 38, 31 and 28% and concurrently the liver synthetase II activity decreased to 75, 43, 29 and 22% of the normal values. In diabetic rats dose response studies showed that with insulin injections of 4, 6, 8 or 10 U/day for 48 h the hepatic synthetase II activity increased to 81, 95, 99 and 103% of the control liver values. In the diabetic rats the insulin-induced rise in liver synthetase II activity was prevented by treatment of the rats with actinomycin.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D007700:Kinetics; D008025:Ligases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D001786:Blood Glucose; D007328:Insulin; D003609:Dactinomycin; D008025:Ligases; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing)