Effects of 3,6-dimethylamino-dibenzopyriodonium edetate on action potentials in guinea pig papillary muscles
Ji, G.J.; Zhao, D.H.; Liu, D.Q.; Sheng, B.H.
Zhongguo Yao Li Xue Bao 14(2): 121-124
1993
ISSN/ISBN: 0253-9756 PMID: 8352002 Document Number: 413027
The effects of 3,6-dimethylaminodibenzopyriodonium edetate (IHC-72) on action potentials (AP) and slow response action potentials of guinea pig papillary muscles were studied with intracellular microelectrodes. IHC-72 12.7, 25.4, and 50.8 mu-mol cntdot L-1 decreased the maximal upstroke velocity (V-max), amplitude of action potential (APA), over shot (OS), and resting potential (RP) while prolonged the action potential duration at 30%, 50%, 90%, and 100% repolarization (APD-30, APD-50, APD-90, and APD-100). IHC-72 25.4 and 50.8 mu-mol cntdot L-1 decreased the APA, V-max, and prolonged APD-50 and APD-90 under high K+ superfusion. IHC-72 25.4 and 50.8 mu-mol cntdot L-1 depressed the automaticity, APA, and maximal diastolic potential (MDP) of the slow response action potentials induced by BaCl-2. The results indicated that IHC-72 might nonspecifically inhibit the transmembrane movement of Ca-2+, Na+, and K+.