Role of chloride ions in liver cell volume regulation.
Role of chloride ions in liver cell volume regulation.
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氯离子在肝细胞体积调节中的作用。
DOI：
10.1152/ajpgi.1991.261.2.g340
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Graf,J
中科院分区：
文献类型：
--
作者：
Haddad,P;Beck,JS;Boyer,JL;Graf,J
肝细胞的低张肿胀之后是调节性体积减少(RVD)，这已被证明涉及K+的促进释放。本研究通过对单个大鼠离体肝细胞体积的视频平面分析、膜电位(Vm)和阻力(Rm)的测定，以及用同位素预负荷的离体肝的~(36)Cl流出量的测定，探讨了C_1~-在RVD中的作用。通过去除50 mM外部氯化钠(对照渗透压的70%)而受到低渗应激的肝细胞在1分钟内从初始体积6.68+/-0.77膨胀到8.27+/-0.88pl(增加24.3+/-3.4%)，并以0.26+/-0.01pl/min的初始速率表现出RVD。外源性氯离子浓度的递减可使RVD的初始速率加快至0.53+/-0.08pl/min。去除氯离子的细胞中，RVD被取消。Vm和Rm对低张应激表现为双相反应。Vm从-35.4+/-2.2 mV到-38.8+/-2.6 mV开始超极化(<15 S)，然后逐渐去极化，1min后达到-30.2+/-2.0 mV。同时，Rm最初(小于15 S)从10 1+/-13增加到12 1+/-17M omga(增加19+/-3%)，然后在1分钟内下降到55+/-4M omega(59+/-4%)。这些变化在恢复等序性后是可逆的。(摘要截断250字)
Hypotonic swelling of liver cells is followed by regulatory volume decrease (RVD), which has been shown to involve facilitated release of K+. In this study, the role of C1- in RVD was examined by videoplanimetric analysis of cell volume and measurement of membrane potential (Vm) and resistance (Rm) in single isolated rat hepatocytes, and by measurement of 36Cl efflux in the isolated perfused liver preloaded with the isotope. Liver cells subjected to hypotonic stress by removal of 50 mM external NaCl (70% of control osmolality) swelled from an initial volume of 6.68 +/- 0.77 to 8.27 +/- 0.88 pl (24.3 +/- 3.4% increase) within 1 min and exhibited RVD at an initial rate of 0.26 +/- 0.01 pl/min. A step decrease in external Cl- accelerated the initial rate of RVD to 0.53 +/- 0.08 pl/min. RVD was abolished in cells that had been depleted of Cl-. Vm and Rm displayed biphasic responses to hypotonic stress. An initial (less than 15 s) hyperpolarization of Vm from -35.4 +/- 2.2 to -38.8 +/- 2.6 mV was followed by a gradual depolarization reaching -30.2 +/- 2.0 mV by 1 min. In parallel, Rm initially (less than 15 s) increased from 101 +/- 13 to 121 +/- 17 M omega (19 +/- 3% increase) and then declined to 55 +/- 4 M omega (59 +/- 4% of initial Rm) within 1 min. These changes were reversible upon return to isotonicity.(ABSTRACT TRUNCATED AT 250 WORDS)