Assuntos
Potenciais Evocados , Síndrome Miastênica de Lambert-Eaton/imunologia , Síndrome Miastênica de Lambert-Eaton/fisiopatologia , Proteínas do Tecido Nervoso/imunologia , Junção Neuromuscular/fisiologia , Sinaptossomos/fisiologia , Animais , Diafragma , Modelos Animais de Doenças , Órgão Elétrico/imunologia , Órgão Elétrico/fisiologia , Potenciais Evocados/efeitos dos fármacos , Técnicas In Vitro , Camundongos , Proteínas do Tecido Nervoso/administração & dosagem , Junção Neuromuscular/efeitos dos fármacos , Nervo Frênico , Potássio/farmacologia , Ratos , Ratos Endogâmicos Lew , Rajidae , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Sinaptossomos/imunologiaRESUMO
Sera from 30 patients with sporadic amyotrophic lateral sclerosis (ALS) were tested to determine their effects at the neuromuscular junction. Spontaneous transmitter release was significantly increased, as evidenced by a 151% increase in MEPP frequency, by sera from 16 ALS patients. In addition, 16 patients' sera elevated EEP quantal content by an average of 89%. Eleven sera produced both effects. There was no consistent change in MEPP amplitude or time course, indicating the absence of a humoral effect on postjunctional ACh receptors or endplate membrane function. These results suggest that a portion of the sporadic ALS patient population possess serum factors that can alter presynaptic function of the motor nerve terminal. Evidence from the present experiments indicates that alterations at the neuromuscular junction are a result of a combination of increased Ca2+ influx into the cell and an independent increase in intracellular calcium concentration.
