ABSTRACT
Dauricine ( Dau ) significantly prolonged monophasic action potential duration of 50% and 90% repolarization ( MAPD50 and MAPD90 ) and functional refractory period (FRP)of the hearts in anesthetized cats in dose-dependent manner. At 9 mg/kg of Dau, MAPD50 was increased from 170?19 ms to 197?20 ms; MAPD90 from 216?16 ms to 249?18 ms; FRP from 177 ? 15 ms to 238 ? 20 ms.Dau 5 mg/kg iv followed by constant perfusion for 30 min could prevent the shortening of MAPD50 in the ischemic boundary area ( BA ) and increased FRP in the non-ischemic area ( NA ) , ischemic central area ( CA ) and BA, and markedly reduced the extent of dispersion of FRP of hearts in anesthetized cats. The results suggest that the antagonizing effect of Dau on the arrhythmias caused by acute myocardial ischemia and reperfusion might be related to its action of prolonging FRP and decreasing the dispersion of FRP in ischemic hearts.
ABSTRACT
The effects of dauricine on tolerance to anoxia in mice and on experimental myocardial ischemia and infarct in rats were investigated .Dauricine was found to be capable of increasing the tolerance of mice to anoxia and prolonging life and decreasing oxygen consump-sion.Dauricine improved the ECG L-Ⅱ "J" point change induced by pituitrin and LAD ligation, and reduced the rate of the development of pathologic Q wave and the infarct size induced by LAD ligation as indicated by N-BT staining in rats. The results suggest that dauricine offered beneficial effect on the experimental ischemia and infarct. Dauricine; Propranolol; Verapamil; Nifedipine; Pituitrin; ECG; Myocardial infarct