前列腺素E2对蟾蜍膀胱膜中血管加压素及鸟嘌呤核苷酸介导的腺苷酸环化酶活性的影响。

The effects of PGE2 on vasopressin--and guanine nucleotide-mediated adenylate cyclase activity in toad bladder membrane.

作者信息

Shimada H, Mishina T, Marumo F

出版信息

Tohoku J Exp Med. 1985 Apr;145(4):427-35. doi: 10.1620/tjem.145.427.

DOI:10.1620/tjem.145.427

Abstract

PGE2 inhibited 10 m U/ml vasopressin-induced osmotic water flow of the toad bladder at 2 X 10(-8) M. PGE2 suppressed vasopressin-mediated cyclic AMP accumulation in epithelial cells and also vasopressin-mediated adenylate cyclase activity in a crude homogenate of the cells. However, PGE2 had no effect on cyclic AMP dependent and independent protein phosphorylation. These findings indicate that PGE2 inhibits vasopressin-induced water flow mainly through suppression of adenylate cyclase activity, and that the role of PGE2 at that point in the reaction leading to increased water permeability following cyclic AMP production may be slight. Under conditions in which the hormone and substrate are depleted, PGE2 and guanine nucleotides, such as GTP and Gpp(NH)p, additively bring about an increase in adenylate cyclase activity.

摘要

前列腺素E2（PGE2）在2×10⁻⁸M浓度时，可抑制10mU/ml血管加压素诱导的蟾蜍膀胱渗透水流动。PGE2可抑制上皮细胞中血管加压素介导的环磷酸腺苷（cAMP）积累，以及细胞粗匀浆中血管加压素介导的腺苷酸环化酶活性。然而，PGE2对cAMP依赖性和非依赖性蛋白磷酸化均无影响。这些发现表明，PGE2主要通过抑制腺苷酸环化酶活性来抑制血管加压素诱导的水流动，并且在cAMP产生后导致水通透性增加的反应中，PGE2在这一点上的作用可能较小。在激素和底物耗尽的条件下，PGE2与鸟嘌呤核苷酸，如鸟苷三磷酸（GTP）和鸟苷-5'-O-(3-硫代三磷酸)（Gpp(NH)p），可协同增加腺苷酸环化酶活性。