Coyle D E, Sperelakis N
Department of Anesthesia, University of Cincinnati College of Medicine, Ohio.
J Pharmacol Exp Ther. 1987 Sep;242(3):1001-5.
The effects of bupivacaine and lidocaine on the slow-rising action potentials, induced by superfusion with high-K+ (26 mM) Tyrode's solution with 10(-6) M isoproterenol, were studied in guinea pig ventricular muscle. The concentrations of bupivacaine or lidocaine necessary to result in a 50% depression of the maximum upstroke velocity were about 10(-5) and 10(-4) M, respectively. The concentrations necessary to completely block the slow action potentials were about 10(-4) M for bupivacaine and 5 X 10(-4) M for lidocaine. The relative potencies of lidocaine to bupivacaine in abolishment of the slow action potentials are in the ratio of 1:5. These results suggest that local anesthetics do affect the slow Ca++ channel of ventricular muscle.
在豚鼠心室肌中，研究了布比卡因和利多卡因对用含10(-6)M异丙肾上腺素的高钾（26mM）台氏液灌流诱发的缓慢上升动作电位的影响。使最大上升速度降低50%所需的布比卡因或利多卡因浓度分别约为10(-5)M和10(-4)M。完全阻断缓慢动作电位所需的浓度，布比卡因为10(-4)M，利多卡因为5×10(-4)M。利多卡因与布比卡因消除缓慢动作电位的相对效价之比为1:5。这些结果表明局部麻醉药确实会影响心室肌的慢钙通道。
