Ca2+ transport across plasma and mitochondrial membranes of isolated hepatocytes
Ca2+ transport across plasma and mitochondrial membranes of isolated hepatocytes
复制标题
Ca2+ 跨离体肝细胞质膜和线粒体膜的转运
DOI：
10.1016/0014-5793(75)80336-x
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发表时间：
1975
期刊：
影响因子：
3.5
通讯作者：
R. Cockrell
中科院分区：
文献类型：
--
作者：
W. Dubinsky;R. Cockrell
钙对分离的肝细胞产生许多重要的代谢作用，例如，它刺激肝细胞生成[1]，提高线粒体NADH/NAD+比值[2]等。钙对肝细胞呼吸的影响是多种多样的，例如，它们包括刺激循环[3]，如分离的线粒体[4]，持续的解偶联[5]或刺激和抑制的复杂相互作用[6]。该离子的亚细胞位点和作用机制尚未确定。目前的研究表明，质膜对Ca 2+的相对渗透性是Ca 2+对呼吸影响的主要决定因素，完整肝细胞对Ca 2+的摄取率约为毛地黄皂苷处理细胞使质膜自由渗透的5%。毛地黄皂苷处理的细胞的Ca 2+蓄积是线粒体转运的结果，并以体外线粒体典型的速率和Ca 2 +/O化学计量发生[4，7]。Ca 2+对完整细胞呼吸和质子转运的影响是完整细胞吸收缓慢和一小部分受损细胞Ca 2+快速积累的综合作用。
Calcium exerts many important metabolic effects upon isolated liver cells, eg it stimulates gluconeogenesis [1], elevates the mitochondrial NADH/NAD÷ ratio [2] etc. The influences of Ca 2÷ upon hepatocyte respiration are varied, eg they include cycles of stimulation [3] such as obtained with isolated mitochondria [4], sustained uncoupling [5] or a complex interplay of stimulation and inhibition [6]. The subcellular loci and mechanism of action of this ion have yet to be determined. The present studies indicate the relative plasma membrane permeability to Ca z÷ is a major determinant of the influence of this ion upon respiration.Ca 2+ uptake by intact hepatocytes occurs at about 5% the rate obtained with cells treated with digitonin to render the plasma membrane freely permeable. Ca 2÷ accumulation by digitonin treated cells is a consequence of mitochondrial transport and occurs at rates and Ca2+/O stoichiometries typical of mitochondria in vitro [4, 7]. The influence of Ca 2+ upon respiration and proton translocation of intact cells is apparently a combination of sluggish uptake by intact cells and rapid Ca 2÷ accumulation by a small fraction of damaged cells.