Blockade of acetylcholine receptors: a model of myasthenia gravis.

In order to block acetylcholine receptors of muscle, the alpha toxin of the Formosan cobra (Naja naja atra) was given intravenously to rats. Electrophysiological and pharmacological changes typical of myasthenia gravis were recorded, including decremental responses to repetitive stimuli, curare sensitivity, neostigmine reversal, and posttetanic phenomena. This model supports the concept that a reduction of available acetylcholine receptors may play an important role in myasthenia gravis.