[In vitro caffeine test on skeletal muscle samples from swine].

Excitable porcine gracilis muscle samples were subjected to an in vitro caffeine test. Muscle samples were taken from pig carcasses or as biopsy from anaesthetized and halothane tested pigs. The caffeine threshold of the muscle was determined, which was the caffeine concentration of the bath that produced a contracture of the muscle sample. The in vitro caffeine test is used in human medicine to diagnose malignant hyperthermia susceptibility. In this study, the caffeine test was adapted to the particular demands of skeletal muscle samples taken from pig carcasses. The used method is described and the results from 62 pigs are reported. The in vitro caffeine test is a reliable and good reproducible method to diagnose malignant hyperthermia susceptibility in pigs. The caffeine threshold characterizes the resistance of Ca(2+)-ion-storages in the muscle fibers with a numerical value. The caffeine threshold allows a gradual evaluation of the muscle quality and represents a valuable addition to the halothane test.