FLUIDITY STATE OF LYMPHOCYTE PLASMA-MEMBRANE IN MALIGNANT HYPERTHERMIA SUSCEPTIBLE PIGS AND HUMANS

Recent studies suggest that abnormalities occur at the lipid level in malignant hyperthermia susceptible humans and pigs. To test this hypot hesis, we first investigated the physical state of plasma membranes of lymphocytes isolated from normal and malignant hyperthermia susceptib le swine. In halothane-challenged pigs, malignant hyperthermia suscept ibility was also assessed by ryanodine binding assay on purified sarco -plasmic reticulum membranes. The results clearly show that plasma mem brane of lymphocytes from malignant hyperthermic pigs are significantl y more fluid than controls. We then attempted to apply the same method ology to lymphocytes prepared from human patients previously diagnosed by the halothane and caffeine contracture test. In that case, there w as no clear relationship between malignant hyperthermia susceptibility and the fluidity state of lymphocyte plasma membranes.