Angiotensin induction of active responses in cultured reaggregates of rat aortic smooth muscle cells.
Angiotensin induction of active responses in cultured reaggregates of rat aortic smooth muscle cells.
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血管紧张素诱导培养的大鼠主动脉平滑肌细胞重新聚集体的主动反应。
DOI：
10.1159/000158360
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Sperelakis,N
中科院分区：
文献类型：
--
作者：
Zelcer,E;Sperelakis,N
研究了正常血压（WKY）和自发性高血压（SHR）大鼠主动脉制备的血管平滑肌细胞再聚群的电活动。WKY（-44.7±0.5 mV）和SHR（-45.6±0.5 mV）重聚集体的静息膜电位无显著差异。电场刺激引起的主动响应由两部分组成：初始尖峰部分（振幅，30-40 mV, +Vmax - 1 - 3 V/s）和平台部分（振幅，10-30 mV，持续时间3-5 s， +Vmax, 0.1-0.3 V/s）。通常刺突成分不存在。维拉帕米、Mn++和无Na+溶液消除了响应的两个组成部分，表明Na+和Ca++电流可能与它们有关。添加10 mMTEA增加了响应的持续时间，而在TEA溶液中添加0.5 mmbacl2则进一步增加了持续时间。在TEA和ba++存在的情况下，穗状成分总是发生。WKY和SHR再聚合的反应没有差异。大剂量血管紧张素II (All)（大剂量浓度为1µM）引起短暂的去极化。在一些细胞中，积极的膜反应是由去极化触发的，有时包括尖刺成分。用Tris或胆碱替代溶液中所有的Na+导致对all的反应丧失，并且在一些细胞中，在添加AH时实际上可以看到超极化。All对维拉帕米不敏感（高达10-5M），但被1 mMMnCl2阻断。WKY和SHR动物的重聚集体对AIL的反应相似。数据表明，培养的血管平滑肌重聚集体具有电兴奋性，对血管紧张素敏感。因此，在培养细胞中必须存在功能性血管紧张素受体。
Electrical activity was studied in cultured reaggregates of vascular smooth muscle cells prepared from the aortas of normotensive (WKY) and spontaneously hypertensive (SHR) rats. There were no significant differences between the resting membrane potentials of WKY (–44.7 ± 0.5 mV) and SHR (–45.6 ± 0.5 mV) reaggregates. Electrical field stimulation elicited active responses that consisted of two components: an initial spike component (amplitude, 30–40 mV; +Vmax1–3 V/s) and a plateau component (amplitude, 10–30 mV; duration 3–5 s; +Vmax, 0.1–0.3 V/s). Often the spike component was absent. Both components of the response were abolished by verapamil, Mn++, and Na+-free solutions indicating that Na+and Ca++currents may be associated with them. Addition of 10 mMTEA increased the duration of the response, and addition of 0.5 mMBaCl2to the TEA solution increased the duration even further. The spike component always occurred in the presence of TEA and Ba++. No differences were observed between responses in WKY and SHR reaggregates. A bolus of angiotensin II (All) (bolus concentration of 1µM) elicited a transient depolarization. In some cells an active membrane response was triggered by the depolarization and sometimes included the spike component. Replacing all the Na+in the solution with either Tris or choline resulted in loss of the response to All, and in some cells a hyperpolarization was actually seen on addition of the AH. The response to All was insensitive to verapamil (up to 10–5M), but was blocked by 1 mMMnCl2. Reaggregates from both WKY and SHR animals gave similar responses to AIL The data indicates that cultured reaggregates of vascular smooth muscle are electrically excitable and are sensitive to angiotensin. Therefore functional angiotensin receptors must be present in the cultured cells.