Single K+ channels in adrenal zona glomerulosa cells. II. Inhibition by angiotensin II.
Single K+ channels in adrenal zona glomerulosa cells. II. Inhibition by angiotensin II.
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肾上腺球状带细胞中的单个 K 通道。
DOI：
10.1152/ajpendo.1992.263.4.e760
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Williams,GH
中科院分区：
文献类型：
--
作者：
Kanazirska,MV;Vassilev,PM;Quinn,SJ;Tillotson,DL;Williams,GH
The effects of angiotensin II (ANG II) on single K+ channels were studied in rat and bovine adrenal zona glomerulosa (ZG) cells, using the patch-clamp technique. ANG II (0.1-10 nM) induced substantial inhibition of inward rectifier and delayed rectifier K+ channel activities in rat and bovine ZG cells. Analysis of single-channel activities showed that the ANG II-induced channel-blocking effect involved reductions in the probability of the open state (Po) and the mean open time. The changes in these channel parameters occurred at all test voltages, indicating that the effect of ANG II was voltage independent. ANG II could not interact directly with the extracellular sides of the membranes in these experiments using cell-attached patches. Therefore, the effect of ANG II on K+ channels must occur through an indirect cytosolic transduction pathway. The ANG II-induced block of K+ channels will result in membrane depolarization, which may activate voltage-dependent Ca2+ channels, thereby increasing cytosolic free Ca2+ and stimulating aldosterone secretion. These channel-modulating actions of ANG II may be an important step in the initial sequence of events underlying its transduction mechanism.
