降钙素基因相关肽对大鼠心肌缺血损伤的保护作用研究

Protective effect of calcitonin gene-related peptide on myocardial ischemic injury in rats

摘要:

目的 研究静脉用降钙素基因相关肽对大鼠心肌缺血损伤的氧自由基影响及心肌保护作用。方法 用单剂量异丙肾上腺素（ＩＳＯ）皮下注射建立大鼠心肌缺血损伤模型，单剂量降钙素基因相关肽静脉注射治疗，２ 小时后采血测定血清心肌酶及血清ＭＤＡ，ＳＯＤ， 同时取心肌组织匀浆测组织ＭＤＡ，ＳＯＤ， 并观察心肌组织显微结构改变。结果 ①ＩＳＯ 损伤组血清和心肌组织ＭＤＡ较正常组升高，血清和心肌组织的ＳＯＤ 较正常组下降；而ＣＧＲＰ治疗组血清和心肌组织的ＭＤＡ 较ＩＳＯ损伤组下降，血清和心肌组织的ＳＯＤ则较ＩＳＯ 损伤组升高（Ｐ＜ ０ ．０５） 。②ＣＧＲＰ治疗组血清ＣＫ，ＬＤＨ 较ＩＳＯ 损伤组明显下降（ Ｐ＜０ ．０５）。③心肌光镜、电镜结果示ＣＧＲＰ组细胞损伤程度明显低于ＩＳＯ损伤组（ Ｐ＜ ０．０５）。结论 静脉用ＣＧＲＰ治疗异丙肾上腺素所致大鼠心肌损伤，能纠正ＭＤＡ 和ＳＯＤ 的失衡，抑制过强脂质过氧化反应，并保护心肌细胞，防止心肌酶漏出，拮抗心律失常。

Abstract:

Objective To evaluate the effect of calcitonin gene-related peptide(CGRP) intravenous on myocardial injury and the oxygen free radicals in rats. Methods Rat myocardial injury model was established by subcutaneous injection of single dose isoproterenol(ISO), and then treated with CGRP single dose IV. Two hours after treatment, blood was taken for determining serum CK,LDH,MDA and SOD tests,and the myocardial tissue was homogeniged for determining tissue MDA and SOD, and microstructures observation proceeded. Results (1)When group ISO injury was compared with the group control, its serum MDA and tissue MDA levels increased apparently,but its serum SOD and tissue SOD levels decreased (P<0.05). Compared with that in group ISO injury the serum MDA and tissue MDA in CGRP treatment group decreased obviously, but its serum SOD and tissue SOD increased obviously(P<0.05). (2)Serum CK and LDH levels in group treatment decreased clearly as compared with that in group injury (P<0.05). (3) Microstructure observation showed that the injury degree of myocardial structure in group CGRP treatment was much less severe than that in group injuried(P<0.05). Conclusions The results suggest that CGRP has effects of protecting the myocardial injury induced by isoproterenol, correcting the imbalance between MDA and SOD level, inhibiting the stronger lipid hyperoxide reaction, preventing the myocardial enzyme leak from injuried cardiomyocyte and antagonizing arrhythmia in rats.