Changes in tetrodotoxin-resistant action potentials after passive transfer of myasthenia gravis patient sera.
Muscle electrical activity has been studied in mice after intraperitoneal injection of sera from myasthenia gravis (MG) patients. Myasthenic serum did not modify the electrical properties of innervated muscle fibres. The resting membrane potential and the action potential parameters remained unchanged. However, tetrodotoxin (TTX)-resistant action potentials of denervated muscles were reduced by myasthenic serum, possibly in association with receptor endocytosis induced by the immunoglobulin. However, a direct effect of MG serum on TTX-resistant sodium channels cannot be ruled out.
Laboratorio Neurofisiologia, Instituto de Investigaciones Medicas Alfredo Lanari, Argentina.
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Losavio
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Muchnik
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Panizza
D000200:Action Potentials / Q000187:drug effects; D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001323:Autoantibodies / Q000494:pharmacology*; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008875:Middle Aged; D009121:Muscle Denervation; D009132:Muscles / Q000294:innervation* / Q000502:physiology; D009157:Myasthenia Gravis / Q000276:immunology*; D011950:Receptors, Cholinergic / Q000276:immunology* / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology*
D001323:Autoantibodies; D011950:Receptors, Cholinergic; D013779:Tetrodotoxin