An investigation of experimental myasthenia gravis.

Guinea-pigs were immunized with antigen prepared from calf thymus and muscle, and from guinea-pig thymus, and rats were immunized with antigen prepared from rat thymus and rat muscle. There was an increased incidence of delayed hypersensitivity and circulating thymus antibodies in the immunized guinea-pigs and an increased incidence of thymitis in the immunized guinea-pigs and rats. However, when compared with control animals, there was no electrophysiological evidence of impairment of neuromuscular transmission in the immunized animals.