Isolated perfused rat heart model was used to observe the protective effects of
berbamine on
myocardial ischemia/
reperfusion injury. The hearts were remarkably injured by 40 min global
ischemia followed by 20 min reperfusion.
Berbamine could significantly improve heart function, prevent
ventricular fibrillation, reduce CK release, preserve Na, K-
ATPase activity, and reduce Na+ gain and K+ loss during
ischemia and Ca2+ overload during reperfusion. With the use of low temperature ESR technique, we found that, in hearts subjected to 40 min
ischemia and 15 sec reperfusion,
oxygen-centered
free radical signals became much more intense. In the presence of
berbamine, these signals decreased. The results showed that
berbamine could alleviate
myocardial ischemia/
reperfusion injury. This effect might be due to (1) preserved myocardial Na, K-
ATPase activity and inhibition of
sodium overload at the end of
ischemia, which might further lead to attenuation of reperfusion-induced
calcium overload, and (2) reduction of
oxygen free radical generation during reperfusion.