PKC在UTP调节猪冠状动脉平滑肌细胞BK_(Ca)通道中的作用

Effect of PKC on the regulation of UTP on BK_(Ca) channels of porcine coronary artery smooth muscle cells

目的:研究UTP对急性酶分离的猪冠状动脉平滑肌细胞上BKCa通道的作用,探讨PKC在其过程中的作用机制。方法:应用cell-attached技术记录急性酶分离的猪冠状动脉平滑肌细胞上BKCa电流。用pCLAMP10.0软件系统进行数据采集及分析。结果:在cell-attached膜片上,80μMUTP可明显激活BKCa通道(P<0.05,n=21)。PLC抑制剂U73122可抑制UTP对BKCa的激活作用(P<0.05,n=5)。PKC激动剂PMA(10nM),可使BKCa通道开放概率明显降低(P<0.05,n=9)。UTP(80μM)预处理细胞之后,PKC特异性抑制剂Bis-Ⅰ(1μM),可使BKCa通道开放概率进一步增加(P<0.05,n=9)。结论:在cell-attached膜片上,UTP经由PLC信使转导通路激活猪冠脉平滑肌细胞BKCa通道;PKC对此过程具有干预作用。

Objective： To study the effect of UTP on BKCa channels in porcine coronary artery smooth muscle cells,and explore the regulatory effect of PKC.Methods： The coronary artery was excised from the heart of porcine.All experiments were done on single smooth muscle cell isolated enzymatically in symmetric high potassium solution and currents were recorded by patch clamp single channel recording technique.pCLAMP10.0 software was used to record and analyze data.Results： In cell-attached patch,UTP（80 μM） enhanced BKCa channels open probability（Po） and reduced the mean close time（Tc）（P0.01,n=21）.In the presence of UTP,the specific blocker of phospholipase C-U73122（10 μM） decreased BKCa channels Po（P0.05,n=5）.Application of PMA（10nM） obviously decreased BKCa channels Po（P0.05,n=9）.In the presence of UTP,Bis-Ⅰ（1μM） increased activation of BKCa channels（P 0.05,n =9）.Conclusions： UTP can activate BKCa channels of porcine coronary ASMCs in cell-attached patches via PLC signal transduction pathway.PKC is involved in UTP mediated BKCa channels activation.