The Course of Myasthenia Gravis and Therapies Affecting Outcome

Injection of rabbits with acetylcholine receptor highly purified from the electric organ of Electrophorus electricus emulsified in complete Freund's adjuvant resulted in the production of precipitating antibody to acetylcholine receptor. After the second injection of antigen, the animals developed the flaccid paralysis and abnormal electromyographs characteristic of neuromuscular blockade. Treatment with the anticholinesterases edrophonium or neostigmine dramatically alleviated the paralysis and the fatigue seen in electromyography.

Immunization of animals with acetylcholine receptor (AChR) protein from the electric organs of Electrophorus electricus and Torpedo californica induces an autoimmune response to the AChR of mammalian skeletal muscle. Rats and guinea pigs develop experimental autoimmune myasthenia gravis (EAMG) after a single inoculation with small quantities of AChR and adjuvant. The indicence and severity of disease appears to depend on the dose of AChR and stability of the emulsion. EAMG is strikingly similar to myasthenia gravis (MG) of man in its clinical picture and its electrophysiological abnormalities. The presence of antibodies to syngeneic rat muscle AChR in the serum of rats with EAMG documents the existence of autoimmunity in the experimental disease. A common immunopathogenesis is suggested for both EAMG and mg.