抗心律失常肽对乳鼠心肌细胞急性缺氧时细胞间传导的影响

目的 研究抗心律失常肽(AAP10)对乳鼠心肌细胞急性缺氧时细胞间传导的影响.方法 原代培养的乳鼠心肌细胞,随机分为正常组、缺氧2 h组和100 nmol/L AAP10干预组,每组n=9.采用划痕标记染料示踪技术测定细胞间通讯,Western blot技术检测缝隙连接蛋白43(Connexin 43,Cx43)磷酸化水平的改变.结果 划痕标记染料示踪技术结果显示缺氧组细胞间传导下降,而AAP10干预后能促进荧光黄的扩散.Western blot结果显示缺氧组总Cx43蛋白表达下降,与正常组比较P＜0.01,而去磷酸化的Cx43(NP-Cx43)蛋白表达不变;AAP10干预组能提高总Cx43蛋白表达,与缺氧组比较P＜0.01,但对NP-Cx43蛋白表达无影响.结论 急性缺氧时磷酸化的Cx43(p-Cx43)蛋白表达下降,而AAP10改善传导主要通过促进Cx43磷酸化.

Effects of Antiarrhythmic Peptide on Intercelluar Communication in Cultured Neonatal Rat Myocytes during Acute Hypoxia

Objective To investigate the effects of the antiarrhythmic peptide AAP10 on the conduction of cultured neonatal rat ventricular myocytes(NRVMs) during acute hypoxia.Methods NRVMs were randomly divided into 3 groups:control group,hypoxia group and AAP10 group(n=9 each).The intercellular communication was evaluated by the scrape loading assay.The state of Cx43 phosphorylation was examined by Western blot.Results The results of scrape loading indicated that the conduction of gap junction was decreased during acute hypoxia,while AAP10 could promote the diffusion of Lucifer Yellow.Western blot analysis showed that total Cx43 was greatly decreased during hypoxia(P<0.01),while dephosphorylated Cx43(NP-Cx43) was unchanged.AAP10 inhibited the decrease of total Cx43(P<0.01),but had no effect on the NP-Cx43.Conclusion During acute hypoxia,phosphorylated Cx43(p-Cx43) was reduced.AAP10 could improve intercelluar communication by enhancing phosphorylation of Cx43.