热休克蛋白70对缺血再灌注未成熟心肌间质的保护作用

Protective effects of heat shock protein 70 on immature myocardial interstitium after ischemia reperfusion

目的观察热休克蛋白70在未成熟心肌中的表达及对缺血再灌注未成熟心肌间质的影响。方法①实验于2001-12/2002-06在华中科技大学同济医学院药理实验室完成。选用出生14～21d的健康新生长耳大白兔12只。随机将兔分为2组对照组和实验组,每组6只。②对照组腹腔注射生理盐水0.4m L,注射后24h取体外心脏,常规建立Langendorff体外心脏灌注模型,灌注15m in转为工作心15m in后停灌45m in,恢复灌注15m in改为工作心30m in;实验组腹腔注射重酒石酸去甲肾上腺素,24h后取体外心脏,方法同对照组。③采用蛋白印迹法测定心肌细胞中热休克蛋白70含量。按公式计算羟脯氨酸含量(样本A值/标准A值×10×稀释倍数×1/组织质量)。采用均相放射免疫竞争法直接测定血浆内皮素1水平。④计量资料差异比较采用t检验。结果兔12只均进入结果分析。①实验组心肌细胞中热休克蛋白70含量(A值)明显高于对照组(P<0.01)。②实验组兔心肌羟脯氨酸含量明显高于对照组(P<0.01),血清内皮素1水平明显低于对照组(P<0.01)。结论腹腔注射重酒石酸去甲肾上腺素诱导未成熟大白兔心脏热休克蛋白70表达,在注射24h后热休克蛋白70表达明显增多,热休克蛋白70可明显减轻未成熟心肌内皮素的释放和心肌胶原的降解。

AIM： To observe the expression of heat shock protein 70 in immature myocardial interstitium, and its influence on immature myocardial interstitium in ischemia reperfusion. METHODS： （1） The experiment was carried out in the pharmacological laboratory of Tongji Medical College, Huazhong University of Science and Technology between December 2001 and June 2002. Twelve healthy newborn white rabbits of 14-21 days old were randomly divided into control group （n=6） and experimental group （n：6）. （2） In the control group, the rats were given intraperitoneal injection of physiological saline （0.4 mL）, and in vitro heart was taken at 24 hours after injection, and then models of Langendorff in vitro heart perfusion were routinely established, perfusion for 15 minutes and turned to operating heart for 15 minutes followed by a rest for 45 minutes, and then the perfusion was recovered for 15 minutes and turned to operating heart for 30 minutes. In the experimental group, the rats were given intraperitoneal injection of arterenol bitartrate, and in vitro heart was taken at 24 hours after injection, the methods were the same as those in the control group, （3） The content of heat shock protein 70 in myocardium was detected with western blot method. The content of hydroxyproLine was calculated （A value of sample/standard A value×10 xdilution timesxl/tissue mass）. The level of enduthelin-1 was directly determined by means of average phase radioimmunocompetition, （4） The t test was applied in comparing the difference of measurement data, RESULTS： All the 12 rabbits were involved in the analysis of results, The content of heat shock protein 70 in myocardium （A value） was ob,Yiously higher in the experimental group than in the control group （P 〈 0.01）. （2） The content of hydroxyproline in myocardium in the experimental group was obviously higher than that in the control group （P 〈 0.01）, and the serum level of endothelin-1 was obviously lower than that in the control group （P 〈 0.01）. CONCLUSION： The expression of heat shock protein 70 in the immature myocardium of rabbits was induced by intraperitoneal injection of arterenol bitartrate, and it obviously increased at 24 hours after the injection, heat shock protein 70 can obviously relieve the release of endothelin and the degradation of interstitium in immature myocardium.