大鼠胰腺β细胞中的调节性容积增加

Regulatory volume increase in rat pancreatic beta-cells.

作者信息

Miley H E, Holden D, Grint R, Best L, Brown P D

机构信息

Cell Physiology Group, School of Biological Sciences, Stopford Building, University of Manchester, Manchester M13 9PT, UK.

出版信息

Pflugers Arch. 1998 Jan;435(2):227-30. doi: 10.1007/s004240050505.

DOI:10.1007/s004240050505

PMID:9382935

Abstract

This study investigated regulatory volume increase (RVI) in rat pancreatic beta-cells. Volume changes in isolated beta-cells were measured by a video-imaging method. Cell shrinkage was induced by exposure to solutions made hypertonic by the addition of 100 mM mannitol. In HEPES-buffered solutions, beta-cells exhibited an RVI which was almost completely abolished by 10 microM bumetanide. These data indicate that Na+-2Cl--K+ cotransporters make a major contribution to RVI in beta-cells. In HCO3--buffered solutions, however, an RVI was observed in the presence of 10 microM bumetanide. This bumetanide-insensitive component of RVI was inhibited by 100 microM amiloride or 100 microM 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS). These data suggest that, in addition to the Na+-2Cl--K+ cotransporter, functionally coupled Na+-H+ exchangers and Cl--HCO3- exchangers may also contribute to RVI in pancreatic beta-cells.

摘要

本研究调查了大鼠胰腺β细胞中的调节性容积增加（RVI）。通过视频成像方法测量分离的β细胞中的容积变化。通过加入100 mM甘露醇使溶液变为高渗来诱导细胞收缩。在HEPES缓冲溶液中，β细胞表现出RVI，而10 μM布美他尼几乎完全消除了这种RVI。这些数据表明，Na⁺-2Cl⁻-K⁺协同转运蛋白对β细胞中的RVI起主要作用。然而，在HCO₃⁻缓冲溶液中，在存在10 μM布美他尼的情况下观察到了RVI。RVI的这种布美他尼不敏感成分被100 μM氨氯地平或100 μM 4,4'-二异硫氰酸根合芪-2,2'-二磺酸（DIDS）抑制。这些数据表明，除了Na⁺-2Cl⁻-K⁺协同转运蛋白外，功能偶联的Na⁺-H⁺交换体和Cl⁻-HCO₃⁻交换体也可能对胰腺β细胞中的RVI有贡献。