The effects of benzamil on in vitro contracture responses of human skeletal muscle to halothane.
1. Inhibition of sodium-calcium exchange using 100 microM benzamil caused contracture development of in vitro skeletal muscle samples from humans susceptible to malignant hyperthermia, but not of samples from normal individuals. 2. This dose of benzamil increased the contracture response of both types of muscle to halothane. 3. At a concentration of 1 microM, benzamil significantly reduced the contracture response to halothane of muscle from malignant hyperthermia individuals. 4. The implications for the role of sodium-calcium exchange in skeletal muscle calcium homeostasis and the pathophysiology of malignant hyperthermia are discussed.
Malignant Hyperthermia Investigation Unit, St James's University Hospital, Leeds, England.
P M
PM
Hopkins
F R
FR
Ellis
P J
PJ
Halsall
D000584:Amiloride / Q000031:analogs & derivatives* / Q000494:pharmacology; D004347:Drug Interactions; D006221:Halothane / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008305:Malignant Hyperthermia / Q000503:physiopathology; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects* / Q000502:physiology
C013407:benzamil; D000584:Amiloride; D006221:Halothane