Antibodies to motor nerve terminals: an electrophysiological study of a human myasthenic syndrome transferred to mouse

J Physiol. 1983 Nov;344:335-45. doi: 10.1113/jphysiol.1983.sp014943.

Abstract

Immunoglobulin G(IgG) prepared from the plasma of patients with a presynaptic disorder of neuromuscular transmission (Lambert-Eaton myasthenic syndrome, l.e.m.s.), or from normal pooled control human plasma, was injected into mice (10 mg daily) for up to 99 days. Micro-electrodes were used to record end-plate potentials from the diaphragm muscle bathed in normal Krebs solution containing tubocurarine (1.0-4.6 microM). At 0.5 Hz nerve stimulation frequency, the quantal content was significantly reduced (P less than 0.01-P less than 0.001) in mice treated with six l.e.m.s. patients' IgG each compared with paired controls. The pooled quantal content was 55 +/- 3 (n = 110 end-plates) for all test animals and 131 +/- 9 (n = 47) for all controls (P less than 0.001). During short trains at 20 or 40 Hz nerve stimulation, control muscles showed marked depression, while test muscles showed either facilitation or less marked depression. Quantal content throughout these trains remained lower than in controls. The results indicate that IgG antibody from l.e.m.s. patients can induce a similar physiologic disorder in injected mice, and they support the view that this antibody interferes with evoked release of transmitter in l.e.m.s. by binding to nerve terminal determinants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Autoantibodies / immunology*
  • Humans
  • Immunoglobulin G / immunology
  • Membrane Potentials / drug effects
  • Mice
  • Middle Aged
  • Motor Endplate / drug effects
  • Motor Endplate / immunology*
  • Motor Endplate / physiology
  • Muscles / innervation
  • Muscular Diseases / immunology*
  • Neuromuscular Junction / immunology*
  • Syndrome
  • Tubocurarine / pharmacology

Substances

  • Autoantibodies
  • Immunoglobulin G
  • Tubocurarine