Cell Na+ activities and transcellular Na+ absorption by descending colon from normal and Na+-deprived rabbits.
Cell Na+ activities and transcellular Na+ absorption by descending colon from normal and Na+-deprived rabbits.
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正常兔和缺钠兔降结肠的细胞 Na 活性和跨细胞 Na 吸收。
DOI：
10.1007/bf00580277
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Schultz,SG
中科院分区：
文献类型：
--
作者：
Turnheim,K;Hudson,RL;Schultz,SG
用Na+选择性微电极测定了家兔降结肠细胞内Na+活性（Na）c与Na+吸收率（INa）之间的关系。（Na）的浓度为13 mM，在6倍范围内不依赖于INa。此外，在低转运蛋白（对照饮食）和高转运蛋白（Na+剥夺）中，顶膜（rm）与基底外侧膜（rs）的斜率电阻比（即rm/rs）没有显著差异，尽管高转运蛋白顶膜的Na+电导平均为低转运蛋白的3倍。这些发现，连同其他实验室报告的结果，强烈表明，醛固酮诱导的顶端膜的电导增加Na+，反过来，进入吸收细胞的Na+的速率，其次是平行增加的能力，细胞挤出Na+穿过基底外侧膜的情况下，持续增加（Na）Ca以及该屏障的电导。
The relation between intracellular Na+activities, (Na)c, determined employing Na+-selective microelectrodes, and the rates of active Na+absorption,INa, by rabbit descending colon was examined whenINawas varied over a wide range by chronic dietary Na+deprivation. (Na)caveraged 13 mM and was independent ofINaover a sixfold range. Further, the ratios of the slope resistance of the apical membrane (rm) to that of the basolateral membrane (rs) (i.e.rm/rs) in low-transporters (control diet) and high-transporters (Na+-deprived) did not differ significantly inspite of the fact that the Na+conductance of the apical membranes of high-transporters was, on the average, three times greater than that of the low-transporters. These findings, together with the results reported by other laboratories, strongly suggest that the aldosterone-induced increase in the conductance of the apical membrane to Na+and, in turn, the rate of entry of Na+into the absorptive cells are followed by parallel increases in the ability of cells to extrude Na+across the basolateral membrane in the absence of a sustained increase in (Na)cas well as the conductance of that barrier.