Immunoglobulin G from a patient with Miller-Fisher syndrome rapidly and reversibly depresses evoked quantal release at the neuromuscular junction of mice.
A neuromuscular blocking factor has been described in the serum of patients with Miller-Fisher syndrome (MFS). We here examined the effect of immunoglobulins (Ig) on neuromuscular transmission in mice recording quantal endplate currents by means of a perfused macro-patch-clamp electrode. Ig and IgM- and IgG-fractions from an anti-GQ1b-positive patient with typical MFS were highly purified. After application of MFS-IgG, quantal release decreased 1000-fold within 2 min. Returning to control solution the average release came back to the baseline level within 4 min. In contrast, control-IgG and MFS-IgM did not cause any blocking effect. The very fast and fully reversible presynaptic blockade of release caused by the highly purified IgG-fraction may be one factor producing muscle weakness in MFS.
Buchwald
B
B
Physiologisches Institut der Technische Universität München Biedersteiner, Germany.
Weishaupt
A
A
Toyka
K V
KV
Dudel
J
J
D000818:Animals; D003711:Demyelinating Diseases / Q000276:immunology*; D003964:Diaphragm / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology; D066298:In Vitro Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D009045:Motor Endplate / Q000187:drug effects; D009469:Neuromuscular Junction / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000276:immunology*; D013577:Syndrome; D013779:Tetrodotoxin / Q000494:pharmacology
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D013779:Tetrodotoxin