Temperature dependence of muscle function in malignant hyperpyrexia-susceptible swine

Contractures induced by halothane, caffeine, suxamethonium chloride and potassium in malignant hyperpyrexia-susceptible (MHS) and control swine skeletal muscle preparations were temperature-dependent, but differed in their temperature response profiles. Increasing the temperatures from 20 degrees C to 37 degrees C increased drug-induced contractures in MHS muscle. At 5 degrees C drug-induced contractures were not inhibited by dantrolene sodium, deuterium oxide or glycerination in either MHS or control muscle. These observations give further support to the view that the abnormality in MHS skeletal muscle is associated with the mechanism of excitation-contraction coupling.