胰岛素对肝脏氨甲酰磷酸合成酶II（谷氨酰胺水解型）活性的作用。

Action of insulin on liver carbamoyl-phosphate synthetase II (glutamine-hydrolyzing) activity.

作者信息

Reardon M A, Weber G

出版信息

Biochem Biophys Res Commun. 1983 Jul 18;114(1):255-60. doi: 10.1016/0006-291x(83)91621-2.

Abstract

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.

摘要

氨甲酰磷酸合成酶II（谷氨酰胺水解）（EC 6.3.5.5）（合成酶II）是从头合成尿苷一磷酸生物合成途径中的首个限速酶。本研究表明，胰岛素对肝脏合成酶II的活性具有调节作用。当注射不同剂量的四氧嘧啶诱导糖尿病时，血浆胰岛素浓度呈剂量依赖性降低至正常值的72%、38%、31%和28%，同时肝脏合成酶II的活性降低至正常值的75%、43%、29%和22%。在糖尿病大鼠中进行的剂量反应研究表明，每天注射4、6、8或10单位胰岛素，持续48小时，肝脏合成酶II的活性增加至对照肝脏值的81%、95%、99%和103%。在糖尿病大鼠中，用放线菌素处理大鼠可阻止胰岛素诱导的肝脏合成酶II活性升高。