梗死灶周围心肌C3G蛋白表达增加参与了异丙肾上腺素诱导的梗死后心脏重塑恶化的发病机制

 目的 通过观察梗死灶周围心肌C3G蛋白的表达及异丙肾上腺素(ISO)对其的影响，探讨梗死灶周围心肌C3G蛋白是否参与了异丙肾上腺素诱导的梗死后心脏重塑恶化的发病机制。方法 按Litwin方法建立心肌梗死(心梗)及假手术模型。 术后7天仍存活的雄性SD大鼠分为心梗组，假手术组，心梗ISO组，假手术ISO组。其中，心梗组及假手术组给予生理盐水5ml/kg每三天一次, 腹腔注射，至干预后12周；心梗ISO组及假手术ISO组给予ISO 5mg/kg每三天一次, 腹腔注射，余方法同上。免疫印迹检测梗死灶周围心肌C3G 蛋白的表达。结果 干预后12周, 梗死灶周围心肌C3G蛋白表达积分光密度标化值分别为：心梗组（1.14±0.29, n=8）, 假手术组（0.90±0.10，n=6）, 心梗ISO组（1.51±0.18，n=10 ）, 假手术ISO组（0.97±0.26, n=8）。心梗组较假手术组、 心梗ISO组较假手术ISO组、及心梗ISO组较心梗组梗死灶周围心肌C3G蛋白的表达均显著增高（P＜0.05）。 结论 梗死灶周围心肌C3G蛋白表达显著增加, 而ISO可使C3G蛋白表达更显著增加； C3G蛋白表达增加参与了梗死后心室重塑，缺血性心肌病及心力衰竭的发病机制，且C3G蛋白表达进一步增加参与了ISO诱导的梗死后心室重塑，缺血性心肌病及心力衰竭恶化的发病机制。

Increased expression of C3G protein in myocardium around the infarcted zones in rats treated with isoproterenol

Objective C3G(CrkSH3-binding guanine nucleotide exchange factor) protein expression was investigated in myocardium around the infarcted zones in rats with ISO treatment or not.Methods Myocardial infarction(MI) and sham-operation models were established.Seven days after operation,surviving rats were divided into MI,sham,MI+ISO and sham+ISO groups respectively,and were treated with physiological buffered saline 5 mL/kg or ISO 5 mg/kg intraperitoneally once every 3 days for 12 weeks respectively.C3G protein expression in myocardium around the infarcted zones was detected by Western blot.Results Twelve weeks after treatment,C3G protein expression was(1.14±0.29,n=8) in the MI group,(0.90±0.10,n=6) in the sham group,(1.51±0.18,n=10) in the MI+ISO group and(0.97±0.26,n=8) in the sham+ISO group respectively.The C3G protein expression in myocardium around the infarcted zones was significantly increased in the MI group compared with the sham group,and in the MI+ISO group compared with the sham+ISO group,and in the MI+ISO groupcompared with the MI group respectively(All P<0.05).Conclusions C3G protein expression significantly increased in myocardium around the infarcted zones.ISO treatment can further increase its expression in myocardium around the infarcted zones.