外源性二酰甘油下调非洲爪蟾卵母细胞中Na(+)-K+泵的活性。

Exogeneous diacylglycerols downregulate the activity of Na(+)-K+ pump in Xenopus laevis oocytes.

作者信息

Khan N A, Quemener V, Moulinoux J P

机构信息

Unité Fonctionnelle de Biologie Cellulaire, Faculté de Médecine, Université de Rennes, France.

出版信息

Exp Cell Res. 1991 Jun;194(2):248-51. doi: 10.1016/0014-4827(91)90361-w.

DOI:10.1016/0014-4827(91)90361-w

PMID:1851097

Abstract

In this study, cell permeable diacylglycerols, sn-1,2-dioctanoglycerol (DiC8), and sn-1-oleoyl-2-acetylglycerol (OAG) were found to downregulate the activity of Na(+)-K+ pump in Xenopus laevis oocytes. Both DiC8 and OAG decreased the binding of [3H]ouabain to intact oocytes while phorbol esters did not appreciably influence the same. These diacylglycerols inhibited the amiloride-sensitive 22Na+ influx and ouabain-sensitive 86Rb+ uptake in the oocytes. Furthermore, DiC8 prevented the 22Na+ efflux from the oocytes preloaded with 22Na+. Addition of H-7 to DiC8- and OAG-treated oocytes stimulated the pump activity curtailed by the two latters. The impairment of Na(+)-K+ pump activity by diacylglycerols suggests that protein kinase C activators may stimulate endocytosis of membrane-coupled Na(+)-K+ ATPase.

摘要

在本研究中，发现细胞可渗透的二酰基甘油、sn-1,2-二辛酰甘油（DiC8）和sn-1-油酰基-2-乙酰甘油（OAG）可下调非洲爪蟾卵母细胞中Na(+)-K+泵的活性。DiC8和OAG均降低了[3H]哇巴因与完整卵母细胞的结合，而佛波酯对其没有明显影响。这些二酰基甘油抑制了卵母细胞中amiloride敏感的22Na+内流和哇巴因敏感的86Rb+摄取。此外，DiC8阻止了预先加载22Na+的卵母细胞中的22Na+外流。向经DiC8和OAG处理的卵母细胞中添加H-7可刺激被后两者抑制的泵活性。二酰基甘油对Na(+)-K+泵活性的损害表明，蛋白激酶C激活剂可能会刺激膜偶联的Na(+)-K+ ATP酶的内吞作用。