低胰岛素浓度在体外刺激大鼠肝脏的可溶性鸟苷酸环化酶活性。

Low insulin concentrations stimulate in vitro the soluble guanylate cyclase activity of rat liver.

作者信息

Laurenza A, Paolisso G, Chiosi E, Spina A M, Illiano G

出版信息

Biochem Biophys Res Commun. 1983 Jul 18;114(1):282-8. doi: 10.1016/0006-291x(83)91625-x.

Abstract

The soluble guanylate cyclase activity of rat liver appears to be stimulated in VITRO by insulin at pMolar concentrations, while proinsulin, denaturated insulin or desoctapeptide insulin, are not able to stimulate the studied enzymic activity. Corresponding concentrations of other peptide hormones such as corticotropin (ACTH) or glucagon, either in the absence or in the presence of bacitracin, do not show any effect on the investigated enzymic system. Insulin stimulation of the soluble guanylate cyclase is characterized by a significant increase in the Vmax together with a decrease of the apparent Km. Insulin at low concentrations doesn't affect the cyclic GMP hydrolyzing activity; conversely higher concentrations of the hormone, while exerting a less marked effect on the guanylate cyclase activity, inhibit the cyclic GMP hydrolyzing activity.

摘要

大鼠肝脏可溶性鸟苷酸环化酶的活性在体外似乎受到皮摩尔浓度胰岛素的刺激，而胰岛素原、变性胰岛素或去八肽胰岛素则无法刺激所研究的酶活性。其他肽类激素，如促肾上腺皮质激素（ACTH）或胰高血糖素，无论有无杆菌肽存在，相应浓度对所研究的酶系统均无任何影响。胰岛素对可溶性鸟苷酸环化酶的刺激表现为Vmax显著增加，同时表观Km降低。低浓度胰岛素不影响环磷酸鸟苷水解活性；相反，较高浓度的该激素虽然对鸟苷酸环化酶活性的影响较小，但会抑制环磷酸鸟苷水解活性。