极化心脏停搏液对离体成熟心肌细胞保护作用的研究

目的观察Na+通道阻滞剂河豚毒素(TTX)极化心脏停搏液对离体成熟大鼠心肌细胞内[Ca2+]i的影响,探讨其对成熟心肌细胞的保护作用。方法成年Wistar大鼠心脏,用酶解法分离成具有搏动性的单个成熟心室肌细胞悬液,随机分成基础组、STH2组和TTX组,STH2组和TTX组分别应用St.ThomasⅡ号停搏液和TTX停搏液处理,建立模拟缺血/再灌注损伤的停搏/复搏细胞模型,采用激光扫描共聚焦显微镜(LSCM)测定各组细胞不同时期的[Ca2+]i。结果 TTX组和STH2组成熟心肌细胞复搏后[Ca2+]i均明显高于基础组,TTX组明显低于STH2组,差异均有统计学意义(P<0.01)。结论极化心脏停搏液较去极化心脏停搏液能减轻成熟心肌细胞Ca2+超载,对离体成熟心肌细胞有较好的保护作用。

Protective Effects of polarizing cardioplegic solution with tetrodotoxin on isolated mature cardiomyocytes

Objective To investigate the effects of polarizing cardioplegic solution with sodium channel inhibitor tetrodotoxin（TTX） through observing the intracellular free Ca2＋ concentration[Ca2＋]i in isolated cardiomyocytes of mature rat.Methods Mature ventricular myocytes with beating were isolated from adult rat＇s hearts by enzymatic dissociation,and were randomly created in Base Group,STH2 Group and TTX Group.Both Group STH2 and Group TTX were arrested by St.Thomas No.2 cardioplegia solution and TTX cardioplegia solution respectively for establishing the arrest/re-beating cell model imitating MIRI,and imaged by laser scanning confocal microscopy（LSCM） was used for measuring[Ca2＋]i of cardiomyocytes in different period.Results [Ca2＋]i of mature cardiomyocytes in both TTX Group and STH2 Group after re-beating were higher than that in Base Group （P0.01）,but in TTX Group,it was lower than that in STH2 Group （P0.01）.Conclusion Contrast depolarized cardioplegia solution,polarized cardioplegia solution could alleviate ischemia reperfusion injury and intracellular Ca2＋ overload in isolated mature cardiomyocytes.