PORCINE MALIGNANT HYPERTHERMIA: CAFFEINE CONTRACTURE OF SINGLE SKINNED MUSCLE FIBERS

Abstract

Using skinned muscle fibers, the response to caffeine was compared between malignant hyperthermia susceptible (MHS) and control swines. The caffeine concentration for the threshold and halfmaximum contracture was markedly lower in MHS swines than in controls. These results agree with those in human malignant hyperthermia (MH). Dantrolene did not exhibit any effect on the dose-response relationship ofcaffeine contracture in the skinned fiber from MHS swines. The muscle fiber diameter was significantly increased in every fiber type of MHS swines. The pathogenesis of porcine MH and effect of dantrolene were discussed.