Mechanism and Effects of Pituitrin on Myocardial Monophasic Action Potential
Yu Wei, Feng Zhiqiang, Yu Liping, Cui Zezhong, Yu Shicheng (Department of Physiology, Luzhou Medical College, Luzhou 646000)
The mechanism and effect of pituitrin on monophasic action potential (MAP) were studied using the technique for recording MAP from epicardium in the closed-chest state in rabbits. The slow of the heart rate, decreased in MAP amplitude and Vmax, lengthening of MAP duration, interval irregularity and ventricular premature beats were observed after pituitrin. Basic idential elec-trophysiological changes from pituitrin as above were presented after atropine or propranolol or phen-tolamine or three blockers to etherly treated. It is suggest that the change in MAP is resulted from the myocardial ischemia for coronary vasoconstriction produced by pituitrin.
【CateGory Index】： R33