热休克蛋白70对兔未成熟心肌和心肌间质的影响

目的: 探讨热休克蛋白70(HSP70)对未成熟心肌和心肌间质的影响. 方法:健康新生长耳大白兔12只随机分为2组. 对照组(C组):ip生理盐水0.4 mL,24 h后取离体心脏,常规建立Langendorff离体心脏灌注模型,灌注15 min转为工作心15 min后停灌45 min,恢复灌注15 min改为工作心30 min;实验组(E组):ip去甲肾上腺素, 24 h后取离体心脏,方法同对照组. 测定心肌细胞中HSP70含量、血流动力学指标、心肌含水量(MWC)、心肌肌酸激酶(CK)和乳酸脱氢酶(LDH)漏出率、三磷酸腺苷(ATP)含量、超氧化物歧化酶(SOD)和丙二醛(MDA)含量、心肌组织羟脯氨酸(HP)含量、内皮素(ET) 含量、心肌细胞内Ca2 含量、心肌线粒体Ca2 -ATPase活性及其Ca2 含量、心肌线粒体合成ATP能力ATP]m,心肌超微结构. 结果:E组HSP70含量明显高于C组(P<0.01);MWC低于C组(P<0.05);ATP含量、SOD活性、心肌线粒体Ca2 -ATPase活性、ATP]m, HP含量优于C组(P<0.01),MDA含量、CK, LDH漏出率、心肌细胞内Ca2 含量、心肌线粒体Ca2 含量、ET含量低于C组(P<0.01),心肌超微结构损伤较C组明显减轻. 结论:HSP70对缺血再灌注未成熟心肌和心肌间质具有明显的保护作用.

Effects of heat shock protein 70 on immature myocardium and myocardial interstitium in rabbits

AIM: To investigate the protective effects of heat shock protein 70(HSP70) on immature myocardium and myocardial interstitium.METHODS: Isolated working rabbit heart model was used in this study.Twelve rabbits(aged 14-21 days) were randomly divided into 2 groups: Control group(C) undergoing 45 min ischemia followed by 45 min reperfusion after distilled water was injected by intraperitoneum 24 h later,and experimental group(E) undergoing 45 min ischemia followed by 45 min reperfusion after norepinephrine was injected by intraperitoneum 24 h later.The HSP70 content,lactate dehydrogenase(LDH) and creatine kinase(CK) leakage,adenosine triphosphate(ATP) and malondialdehyde(MDA) content,superoxide dismutase(SOD) activity,hydroxyproline(HP) and endothelin(ET) content,myocardial cell Ca~(2+) content,Ca~(2+)-ATPase activity of mitothondia(Ca~(2+)-ATPase]_m) and its Ca~(2+) content(Ca~(2+)]_m),synthesizing ATP activity of mitochondria(_m) and myocardial ultrastructure were tested.RESULTS: The cardiac function recovery was better in E group than C group(P<0.05).The HSP70 content,ATP content,SOD activity,HP,Ca~(2+)-ATPase]_m activity and _m activity were higher in E group than C group(P<0.01).The MWC,LDH and CK leakage,MDA content,ET,myocardial cell Ca~(2+) content and Ca~(2+)]_m content were lower in E group than C group(P<0.01).The myocardial ultrastructure injuries were milder in E group than in C group.CONCLUSION: HSP70 has obvious protective effects on immature myocardium and myocardial interstitium.