高渗灌注减轻正常及高血压大鼠心脏缺血再灌注损伤

目的：观察体外高渗灌注对正常及高血压大鼠心肌缺血及再灌注损伤的影响．方法：利用体外心脏逆行灌注装置将大鼠心脏在予以正常灌注液或高渗透压灌注液灌注后进行缺血及再灌注．监测缺血前后心肌功能、缺血后心肌肌酸激酶释放量,用高效液相加电化学法测定心肌儿茶酚胺释放量,用原子吸收光谱法测定再灌注后心肌钙离子含量．结果：高渗灌注可显著减轻正常及高血压大鼠心肌缺血损害,改善高血压大鼠缺血后心功能,减少心肌儿茶酚胺释放,但未能减少再灌注后心肌钙含量．结论：高渗灌注减轻心肌缺血与再灌注损害,其作用可能与减少心肌儿茶酚胺释放有关．

Hypertonic perfusion reduced myocardial injury during subsequent ischemia and reperfusion in normal and hypertensive rats

AIM: To determine the effects of hypertonic solution on myocardial ischemia and reperfusion injury in normal and stroke-prone hypertensive rat hearts in vitro. METHODS: Hearts were perfused in an isolated-perfused Langendorff apparatus and perfused with normal or hypertonic solution(360 mOsm/L, by addition of NaCl to the normal perfusate of 300 mOsm/L) before subjected to 30 min ischemia followed by 40 min isotonic reperfusion. Heart function, myocardial creatine kinase leakage, norepinephrine release, and ventricular calcium content were determined. RESULTS: Normal rat hearts with hypertonic perfusion showed higher recovery rate of spontaneous beating than control hearts after ischemia. Hypertensive rat hearts perfused with hypertonic solution also had better recovery in diastolic function and less creatine kinase leakage than hypertensive controls. Concomitantly, myocardial release of norepinephrine was also reduced from hypertensive hearts perfused with hypertonic solution. There was no significant difference in myocardial calcium content between normal and hypertonic perfused hypertensive hearts. CONCLUSION: Hypertonic perfusion may precondition the hearts and protect them from ischemia and reperfusion injury in both normal and hypertensive rats. The modulation of hypertonic perfusion on myocardial norepinephrine release and its role in cardioprotection needs further investigation.