Effects of bretylium tosylate on electrophysiologic properties of normal and digitalized papillary muscles of guinea pigs.
The effects of bretylium tosylate (BT) on the electrophysiologic properties of normal and digitalized papillary muscles isolated from guinea pigs were studied with regular glass microelectrode. BT prolonged effective refractory period (ERP) and action potential duration (APD) of normal papillary muscles. The ERP and APD of papillary muscles were shortened by perfusion with ouabain (Oua) 0.2 mumol.L-1. No recovery was seen in perfusion without drug for 30 min. In digitalized papillary muscles with Oua, ERP, APD90, and APD50 were prolonged by BT 120 mumol.L-1 form 175 +/- 20, 187 +/- 20, and 146 +/- 21 ms to 222 +/- 21, 220 +/- 19, and 190 +/- 19 ms, respectively. The results demonstrated that BT can prolong ERP and APD of papillary muscles digitalized with Oua.
Liu
Y C
YC
Department of Physiology, Zhejiang Medical University, Hangzhou, China.
Zhu
P J
PJ
Li
Z Y
ZY
Yu
D Z
DZ
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001950:Bretylium Tosylate / Q000494:pharmacology*; D004594:Electrophysiology; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D010042:Ouabain / Q000037:antagonists & inhibitors; D010210:Papillary Muscles / Q000187:drug effects* / Q000502:physiology; D012032:Refractory Period, Electrophysiological / Q000187:drug effects
D010042:Ouabain; D001950:Bretylium Tosylate