缺血预适应对兔心肌缺血的保护机制及腺苷的作用

Protective mechanism of ischemic preconditioning against myocardial ischemia and adenosine effects in rabbit

目的：研究缺血预适应（ＩＰＣ）对兔心肌缺血的保护机制及静滴腺苷与心肌梗塞面积之间的关系．方法：采用冠状动脉结扎法建立兔在体心脏缺血预适应模型，以高效液相色谱测定心肌组织及血液腺苷含量，计算机图像分析左室总面积及梗塞面积．结果：ＩＰＣ组血液腺苷含量［（３．０１±０．０２）μｇ／ｍｌ］高于对照组［（２．２５±０．１９）μｇ／ｍｌ］（Ｐ＜０．０５），心肌腺苷含量［（０．８５±０．０４）ｍｇ／ｇ］与对照组［（０．２７±０．０２）ｍｇ／ｇ］比较差异显著（Ｐ＜０．００１），心肌梗塞面积［（８４．８４±６．５４）ｍｍ２］显著低于对照组［（１７５．５５±１１．５８）ｍｍ２］（Ｐ＜０．００１），心肌梗塞面积与腺苷含量之间有显著的负相关性（ｒ＝－０．８９７４，Ｐ＜０．０１），缺血前静滴腺苷使心肌梗塞面积［（７７．１７±１２．８）ｍｍ２］较对照组显著缩小（Ｐ＜０．００１）．结论：动物实验提示腺苷参与了ＩＰＣ对心肌缺血的保护作用；缺血前静滴腺苷使心肌梗塞面积缩小．

Objective: To study the protective mechanism of ischemic preconditioning (IPC) against myocardial ischemia in rabbits and the relationship between intravenous drip of adenosine and myocardial infarct size. Methods: IPC models were set up in living rabbits by coronary arterial ligation. Adenosine contents in myocardial tissue and blood were determined by high performance liquid chromatography. The total area of left ventricle and myocardial infarct size were analysed by computerized image. Results: Blood adenosine contents in IPC group [(3.01±0.02) μg/ml] was higher than that in control group [(2.25±0.19) μg/ml] ( P <0.05). Myocardial adenosine contents in IPC group [(0.85±0.04) mg/g] was significantly higher in comparison with control group [(0.27±0.02) mg/g] ( P <0.001). The myocardial infarct size in IPC group [(84.84±6.54) mm 2] was significantly smaller than that in control group [(175.55±11.58) mm 2] ( P < 0.001 ). There was an obvious negative correlation between adenosine content and myocardial infarct size ( r =-0.8974, P <0.01). Intravenous drip of adenosine before ischemia could obviously reduce myocardial infarct size [(77.17±12.8) mm 2] ( P <0.001) as compared with control group. Conclusion: The results suggest that adenosine participates in the protective effects of IPC on myocardial ischemia, intravenous drip of adenosine before ischemia can reduce the myocardial infarct size.