钠跨角膜内皮细胞衍生的质膜囊泡转运途径的测定

Determination of pathways for sodium movement across corneal endothelial cell derived plasma membrane vesicles.

作者信息

Wigham C G, Kaila D, Hodson S A

机构信息

Department of Optometry and Vision Sciences, University of Wales College of Cardiff, UK.

出版信息

Biochim Biophys Acta. 1994 Nov 23;1196(1):88-92. doi: 10.1016/0005-2736(94)90299-2.

DOI:10.1016/0005-2736(94)90299-2

PMID:7986815

Abstract

A bovine corneal endothelial cell plasma membrane vesicle preparation was used to investigate passive Na+ transport across the plasma membrane of these cells. Sodium accumulation rate into the vesicle was not dependent on the presence of HCO3- or a HCO3- gradient, but was stimulated by a trans-vesicle pH gradient. Amiloride, furosemide and DIDS all reduced the rate of Na+ accumulation. The data indicate the presence of at least two independent pathways for passive sodium movement across the vesicle: the first probably via a Na+/H+ exchanger and the second a furosemide inhibitable Na+ entry mechanism. No evidence was found for direct Na(+)-HCO3- coupled transport.

摘要

采用牛角膜内皮细胞质膜囊泡制剂研究了Na⁺在这些细胞的质膜上的被动转运。囊泡内的钠积累速率不依赖于HCO₃⁻的存在或HCO₃⁻梯度，但受到跨囊泡pH梯度的刺激。氨氯吡脒、呋塞米和DIDS均降低了Na⁺积累速率。数据表明，至少存在两条独立的途径使钠被动通过囊泡：第一条可能是通过Na⁺/H⁺交换体，第二条是呋塞米可抑制的Na⁺进入机制。未发现直接的Na⁺-HCO₃⁻偶联转运的证据。