中文摘要：

目的：观察线粒体乙醛脱氢酶2 （aldehyde dehydrogenase 2,ALDH2）在糖尿病大鼠不同阶段导致心肌损伤中的变化,并分析其可能机制.方法：采用链脲佐菌素（streptozotocin,STZ）55 mg/kg腹腔注射复制糖尿病大鼠模型,造模成功后分别于4、8、12周时行离体心脏灌流,测定血流动力学指标;采用酶联免疫吸附实验（ELISA）检测血浆白细胞介素1（IL-1）、白细胞介素4（IL-4）水平及心肌组织4-羟壬烯醛（4-hydroxynonenal,4-HNE）含量;测定心肌组织ALDH2活性;RT-PCR测定心肌组织Bax、Bcl-2 mRNA的表达.结果：与对照组相比,糖尿病组左室发展压（left ventricular developed pressure,LVDP）、心率（HR）和左室做功（rate pressure product,RPP）明显降低（P＜0.05或P＜0.01）,血浆IL-1水平增加（P＜0.01）,IL-4水平降低（P＜0.01）,心肌组织ALDH2活性下降（P＜0.01）,4-HNE含量增加（P＜0.01）;Bcl-2/Bax mRNA比值降低（P＜0.01）;随着糖尿病病程的延长,LVDP、HR和RPP进一步降低（P＜0.01）,血浆IL-4水平降低（P＜0.05或P＜0.01）,IL-1水平增加,心肌组织ALDH2活性进一步降低（P＜0.01）,心肌组织4-HNE明显增加（P＜0.01）、而Bcl-2/Bax mRNA比值降低（P＜0.05或P＜0.01）.结论：随着糖尿病病程的延长,炎性损伤逐渐加重,凋亡增加,其机制可能与心肌ALDH2活性逐渐降低有关.

英文摘要：

AIM：To investigate the changes of aldehyde dehydrogenase 2 （ALDH2） on myocardial injury in different stages of diabetic rats and analyze the related mechanism.METHODS：Diabetic （DM） model in SD rat was induced by a single intraperitoneal injection of 55 mg/kg streptozoticin （STZ）.DM rats were divided into fourth week （DM4W）,eighth week （DM8W） and twelfth week （DM12W） groups.The ventricular hemodynamic parameters were recorded,plasma interleukin-1 （IL-1）,interleukin-4 （IL-4） and cardiac 4-hydroxynon-2-enal （4-HNE） levels were determined by enzyme-linked immuno sorbent assay （ELISA）,cardiac ALDH2 activity was measured.The expressions of Bax and Bcl-2 at mRNA level of left anterior myocardium were detected by RT-PCR.RESULTS：In contrast to control group,in DM4W,DM8W and DM12W groups,left ventricular development pressure （LVDP）,heart rate （HR） and left ventricular work （RPP） were decreased （P 〈 0.01）,plasma IL-1 level was increased while IL-4 level was decreased （P〈 0.01）.Cardiac 4-HNE level was increased,and ALDH2 activity was decreased（P〈0.01）.The expression of Bax mRNA level was increased （P 〈 0.01）,Bcl-2 mRNA level was decreased（P〈0.01） and Bcl-2/Bax mRNA were decreased（P〈0.01）.And with the development of diabetic progression,LVDP,HR,RPP,IL-4,ALDH2 activity and Bcl-2/Bax mRNA were further reduced （P 〈 0.05 or P〈0.01）.4-HNE and IL-1 levels were increased（P 〈 0.05 or P 〈 0.01）.CONCLUSION：With the development of diabetes,cardiac ALDH2 activity was further decreased,which may be related to the increase of inflammatory injury and the happening of apoptosis.