关键词: 再灌损伤, 达乌尔黄鼠, 肌酸激酶, 缺灌损伤

Abstract: Isolated hearts tacken from nonhibernating ground squrrel in Autumn were perfused by Langendorff method with Krebs-Henseleit solution. Hearts were first perfused for 10 min to establish steady state, then stopped for 15 min ischemia (noperfusion), and finally followed by 10 min reperfusion. Coronary effluents were sampled at certain time intervals during noperfusion and reperfusion period. The enzymatic activity of CK(U·L^-1) was analysed from the coronary effluent, in the mean time the ECG and contraction amplitude were measured. Parallel experiments with the same protocal have been performed in nonhibernator animal, rat, for comparasion. During 15 min noperfusion period there was a remarkable CK release from both animal hearts. The amount of CK release was proportional to the noperfusion time course in both hearts, but the extent of CK release form rat heartwas much more bigger than that of ground squirrel. During reperfusion period the CK release of rat heart was biphasic while that of the ground squirrel was monophasic and the peak of the 1st releasing phase of the former (255±17 U·L^-1)was much higher than that of the later (179±32U·L^-1). The incidence of ventricular fibrillation and ventricular tachycadia as well as the percentage of decreasedcontraction amplitude were all significantly reduced in ground squirrel heart in comparation with rat heart. These results indicate that the heart from ground squirrel exhibits a stronger resistence to ischemiareperfusion injury than that from rat, presenting a striking contrast between hibernator and nonhibernator.

Key words: reperfusion injury, ground squirrel, creatine kinase, ischemia (noperfusion) injury