中文摘要：

目的：通过观察运动训练对老龄大鼠心肌多胺代谢、心肌抗炎及抗氧化能力的影响,探讨多胺代谢在运动训练延缓心肌衰老中的作用.方法：实验分为3组：老年运动组（Old＋Ex）,18月龄Wistar大鼠梯度跑台运动6周;老年组（Old）,与Old＋Ex组月龄相同的Wistar大鼠;青年组（Young）,3月龄Wistar大鼠.高效液相色谱测定心肌组织中多胺（腐胺、精脒和精胺）含量;[14C]标记液闪计数方法测定心肌组织中多胺合成限速酶鸟氨酸脱羧酶 （ODC） 与多胺分解限速酶精脒/精胺乙酰转移酶 （SSAT） 活性;比色法检测心肌组织中超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量;酶联免疫吸附（ELISA）法检测心肌组织中肿瘤坏死因子α（TNF-α）和白细胞介素1β（IL-1β）含量;超声心动图记录大鼠心脏功能;透射电镜观察心肌组织超微结构变化.结果：与Young组比,Old组大鼠心肌组织中ODC活性下降,SSAT活性升高,精脒、精胺及总多胺池水平显著降低;心肌SOD活性下降,MDA、TNF-α和IL-1β水平升高（P〈0.05）;超声心动图显示,Old组大鼠左心室收缩末期直径（LVESD）与舒张末期直径（LVEDD）均明显增大,左心室射血分数（LVEF）与缩短分数（LVFS）降低（与Young组比,P〈0.01）.Old＋Ex组大鼠心肌组织中ODC活性增加,SSAT活性下降,精脒及总多胺池水平明显增加;心肌SOD活性升高,MDA、TNF-α和IL-1β水平均显著降低（与Old组比,P〈0.05）;左室功能有明显改善.超微结构观察可见Old组心肌肌丝排列不整齐,可见大量脂褐素颗粒沉积,线粒体基质疏松;Old＋Ex组心肌肌节结构清晰,线粒体基质致密,嵴排列整齐.结论：运动训练通过上调多胺合成代谢、抑制其分解代谢对抗衰老引起的心肌多胺水平降低;运动训练可提高老龄心肌抗炎、抗氧化能力.维持老龄心肌多胺池在适当水平可能是运动延缓心肌衰老的部分机制之一.

英文摘要：

AIM： To explore the effects of exercise training on myocardial polyamine metabolism in aged rats. METHODS ： Wistar rats were divided into 3 groups： old ＋ exercise group （ Old ＋ Ex）, old group （Old） and young group （Young）. High performance liquid chromatography was used to test the content of myocardial polyamines （putrescine, spermidine and spermine）. The activity of polyamine synthesis and catabolism rate limiting enzyme ornithine decarboxy lase （ODC） and spermidine/spermine acetyltransferase （SSAT） was analyzed by [ t4C ] labeling. The level of malondial dehyde （MDA） and the activity of superoxide dismutase （SOD） in the myocardium were detected by colorimetric method. The levels of TNF ct and IL 113 were determined by enzyme linked immunosorbent assay. The cardiac functions were measured by echocardiography. The changes of myocardial uhrastructure were observed under transmission electron micro scope. RESULTS： （ 1 ） Compared with Young group, ODC activity decreased, SSAT activity increased, and the levels of spermidine, spermine and total polyamine were significantly decreased in Old group. SOD activity also decreased signifi candy, the content of MDA, TNF-α and IL-1β also increased dramatically in Old group. In the old rats, both left ven tricular end systolic diameter （LVESD） and end diastolic diameter （LVEDD） increased, while left ventricular ejection fraction （LVEF） and fractional shortening （LVFS） decreased. （2） Compared with Old group, ODC activity increased,SSAT activity decreased, the levels of spermidine and total polyamine significantly increased, SOD activity increased signif icantly, and the content of MDA, TNF-α and IL-1 β decreased dramatically in Old ＋ Ex group. The functions of left ventricle also improved significantly in Old ＋ Ex group. （3） Ultrastructural observations indicated that the myofilament and mitochondrial cristae were irregular and mitochondrial matrix density decreased in old rat heart. The cardia