四周模拟失重大鼠后身动脉平滑肌细胞钾电流的改变

发布时间：2019-01-26 20:37

【摘要】：本文采用全细胞膜片钳方法观察 4周尾部悬吊大鼠 (tail suspendedrats,SUS)隐动脉及肠系膜前动脉第 2～ 6级动脉分支血管平滑肌细胞 (vascularsmoothmusclecells,VSMCs)钾电流密度的变化。结果表明 :SUS大鼠后身动脉VSMCs的静息电位 (RP)较对照大鼠 (CON)后身动脉VSMCs的RP更负。SUS组隐动脉和肠系膜小动脉VSMCs的全细胞钾电流密度较CON组显著增加。其中 ,SUS组的隐动脉和肠系膜小动脉VSMCs的大电导钙激活钾离子通道 (BKCa)和电压激活钾离子通道 (KV)电流密度较CON组的BKCa和KV 电流密度均显著增加。以上结果提示 ,VSMCs的超极化及进一步引起的通过电压依赖性钙离子通道的钙内流减少可能是模拟失重引起后身动脉反应性降低的电生理机制之一
[Abstract]:The changes of potassium current density in vascular smooth muscle cells (vascularsmoothmusclecells,VSMCs) from the saphenous artery (saphenous artery) and the anterior mesenteric artery (AMA) of 4-week tail suspended rats (tail suspendedrats,SUS) were observed by whole-cell patch clamp method. The results showed that the resting potential (RP) of VSMCs in the posterior body artery of SUS rats was more negative than that of the RP of VSMCs in the (CON) posterior body artery of control rats. The whole cell potassium current density of saphenous artery and small mesenteric artery VSMCs in SUS group was significantly higher than that in CON group. The large conductance calcium activated potassium channel (BKCa) and voltage activated potassium channel (KV) current density of saphenous artery and mesenteric arteriole VSMCs in SUS group were significantly higher than those in CON group and BKCa and KV groups. These results suggest that the hyperpolarization of VSMCs and the further decrease of calcium influx through voltage-dependent calcium channels may be one of the electrophysiological mechanisms of hyporesponsiveness of posterior body artery induced by simulated weightlessness.
【作者单位】：第四军医大学航空航天生理学教研室第四军医大学航空航天生理学教研室第四军医大学航空航天生理学教研室第四军医大学航空航天生理学教研室
【基金】：ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina (No 30 170 35 5,30 2 0 0 0 90 )
【分类号】：R852.22

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