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Effect of aging on efficacy of ischemic preconditioning

衰老对缺血预适应疗效的影响

基本信息

批准号：
06670743
负责人：
TANI Masato
金额：
$ 1.41万
依托单位：
KEIO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The effects of againg on the recovry of function and metabolites, reperfusion-induced arrhytmias, and sensitivity to PC were investigated in Langendorff-perfused rat hearts. Hearts from young (Y : 12 W/S) or pre-senile (P : 50 W/S) rats were subjected to 15,20, or 25-min global ischemia (GI) followed by 30-min of reperfusion. In some hearts from Y or P,GI was preceded by PC with three 5-min episodes of ischemia with intermittent perfusion. Left ventricular (LV) function (LV pressures, rates of LV pressure development and relaxation) and surface electrocardiogram were monitored during experiments. After perfusion protocol was completed, hearts were frozen and extracted for metabolite assays. There were no differences in cardiac function and myocardial energy metabolites during normoxic perfusion or at the end of ischemia between Y and P.However, recoveries of LV developed pressure, peak positive and peak negative dP/dts (30-50% of Y), and high-energy phoshates (50-60% of Y) were poorer in P with marked increase in LV end-diastolic pressure after anyperiods of GI as compared with those in Y.The incidence of ventricular tachycardia/fibrillation was higher (50% vs.12.5% after 20-min of GI) in P than in Y.PC improved recovery of contractile function (30-50%) and reduced reperfusion arrhythmias in Y whereas no beneficial effects were obtained by the maneuver in P.The results demonstrated that myocardial sensitivity to ischemia-reperfusion injury increased with aging. Furthermore, PC might become less effective with aging.

研究了agon对langendorff灌注大鼠心脏功能和代谢物恢复、再灌注性心律失常和PC敏感性的影响。年轻大鼠（Y: 12 W/S）或老年前期大鼠（P: 50 W/S）的心脏分别进行15、20或25分钟的全身缺血（GI），然后进行30分钟的再灌注。在Y或P的一些心脏中，GI之前有3次5分钟的间歇性灌注缺血发作。实验期间监测左室功能（左室压、左室压发展和舒张率）和体表心电图。灌注方案完成后，将心脏冷冻并提取用于代谢物分析。在正常灌注和缺血结束时，Y和p之间的心功能和心肌能量代谢物没有差异，但左室恢复出现压力，峰值阳性和峰值阴性dP/dts （Y的30-50%）。P组的室性心动过速/心室颤动发生率（50% vs. GI 20 min后12.5%）高于Y组（P组为50%），可改善Y组的收缩功能恢复（30-50%），减少再灌注心律失常，而P组无任何有益作用缺血再灌注损伤随年龄增长而增加。此外，PC可能会随着年龄的增长而变得不那么有效。