Effects of adenylate cyclase activators on porcine skeletal muscle in malignant hyperpyrexia

The effect of adenylate cyclase activation on the in vitro contractures of control and malignant hyperpyrexia susceptible (MHS) porcine muscle was investigated. While fluoride and molybdate ions potentiated drug-induced contractures in control muscle, other activators of adenylate cyclase (forskolin and noradrenaline) did not. Furthermore, fluoride and molybdate had no effect on MHS skeletal muscle contractility. Cyclic AMP content, basal adenylate cyclase activity and molybdate-stimulated adenylate cyclase activity of MHS skeletal muscle was not significantly different from that of control muscle. It is concluded that increased activity of adenylate cyclase does not represent the primary skeletal muscle defect which predisposes to porcine MH.