Effects of dauricine, quinidine, and sotalol on action potential duration of papillary muscles in vitro
Guo, D.L.; Zeng, F.D.; Hu, C.J.
Zhongguo Yao Li Xue Bao 18(4): 348-350
1997
ISSN/ISBN: 0253-9756 PMID: 10072920 Document Number: 476608
AIM: To compare the characteristics of dauricine, sotalol, and quinidine on action potential duration (APD). METHODS: Using intracellular microelectrode method to record APD in guinea pig papillary muscles. RESULTS: Dauricine 20 mu-mol cntdot L-1 prolonged action potential at 90% repolarization, the percent of APD prolongation were 22 +- 8, 11 +- 6, 9 +- 5, 7 +- 5, 6 +- 3, 4.3 +- 2.8, 4.5 +- 2.8 at the cycle lengths of 200 -2000 ms, dauricine became more effective in lengthening APD at short cycle lengths. The effect of dauricine on prolonging APD exhibited normal use-dependence, whereas quinidine 1 mu-mol cntdot L-1 and sotalol 10 mu-mol cntdot L-1 were less effective in lengthening APD at short cycle lengths. The effect of quinidine and sotalol on AM exhibited reverse use-dependence. CONCLUSION: The effect of dauricine on AM depends on activation frequency.