热休克蛋白70表达对未成熟心肌和心肌间质的保护作用

目的 观察热休克蛋白70(HSP70)对未成熟心肌和心肌间质的保护作用.方法 健康新生长耳大白兔30只随机分为5组.对照组:腹腔注射生理盐水0.4 ml 24 h后取离体心脏,建立Langendorff离体心脏灌注模型;E4h、E12h、E24h、E48h组,腹腔注射去甲肾上腺素,4、12、24、48 h后分别取离体心脏,方法同对照组.测定心肌细胞中HSPT0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 E24h组与其他各组比较,HSPT0含量明显增高(P＜0.01),MWC(72.48±1.36)低于其他各组(P＜0.05),ATP含量(11.64±1.87)、SOD活性(235.83±12.30)、心肌线粒体Ca2+-AT-Pase活性(18.46±1.95)、[ATP]m(106.26±9.42),HP含量(6.45±1.53)优于其他各组(P＜0.01),MDA含量(1.17±0.12)、CK(57.38±4.75),LDH漏出率(37.28±3.26)、心肌细胞内Ca2+含量(2.54±0.34)、心肌线粒体Ca2+含量(38.37±3.61)、ET含量(76.84±10.37)低于其他各组(P＜0.01),心肌超微结构损伤较其他各组明显减轻.结论 腹腔注射去甲肾上腺素24 h后可诱导未成熟心肌HSP70高表达,一定量的HSP70表达可明显减轻未成熟心肌和心肌间质的缺血再灌注损伤.

The protective effects of heat shock protein 70 on immature myocardium and myocardial interstitium

Objective To investigate the protective effects of heat shock protein 70(HSPT0)on immature myocardium and myocardial intcrstitium.nethods Thirty rabbits(aged 14-21 days)were randomly divided into 5 groups.In control group(C),was isolated working rabbit heart model after distilled water was injected 24 h intreaperitoneally.E4h group,E12 h group,E24 hgroup and E48h group were also underwent isolated working rabbit hean model after norepinephrine was injected 4,12,24,48 h intreaperitoneally respectively.The HSPTO content,lactate dehydrogenase(LDH)and creatine kinase(CK)leakage,adenosine triphosphate(ATP)and malondialdehyde(MDA)contents,superoxide dismutase(SOD)activity,hydroxyproline(HP)and endothelin(ET)contents,Ca2+content in myocardia,Ca2+-ATPase activity in mitochondria([Ca2+-ATPase]m)and Ca2+ content([Ca2+]m),synthesizing ATP activity of mitochondfia([ATP]m)and myocardial uhragtructure were tested.Results The cardiac function recovery wag better in E24 h group than that of other groups(P＜0.05).The HSP70 content,ATP content (1 1.64±1.87),SOD activity(235.83±12.30),HP(6.45±1.53),[Ca2+-ATPase]m activity(18.46±1.95)and[ATP]m activity(106.26±9.42)in E24 hgroup were higher than those of other groups(P＜0.01).The MWC(72.48±1.36),LDH(37.28±3.26)and CK(57.38±4.75)leakage,MDAcontent(1.17±0.12),ET(76.84±10.37),Ca2+content in myocardium(2.54±0.34)and[Ca2+]mcontent(38.37±3.61)in E24 hgroup were lower than those of other groups(P＜0.01).The myocardial ultrastructure injuries in E24 h group were milder than those of other groups.Conclusion Twenty-four h after peritoneal injection of norepinephrine,high expression of HSP70 can be induced in the immature myocardium.Some expression of HSP70 can obviously alleviate tlle ischemia-reperfusion injmy of immature myocardium and myocardial interstitium.