Altered calcium in motoneurons by IgG from human motoneuron diseases.
OBJECTIVE
The effect of IgG from patients with multifocal motor neuropathy (MMN) on the content and distribution of calcium in spinal motoneurons was compared with the effect of IgG from patients with sporadic amyotrophic lateral sclerosis (SALS) and IgG from normal individuals.


METHODS
Different purified IgG samples were injected intraperitoneally in mice. Then, the animals were subjected to histochemical techniques to visualize calcium in electron microscopic sections.


RESULTS
Quantitative morphometric analysis verified that IgG from MMN decreased the vesicular and axoplasmic calcium content in the axon terminals at the neuromuscular junctions and had no influence on the perikaryon. In contrast to this, IgG from patients with SALS increased the intracellular calcium both in the axon terminal and in the perikaryon. IgG from normal individuals exerted no effect. Elevated intracellular calcium may contribute to motoneuron degeneration. The lack of such effect with MMN immunoglobulins helps to explain the relative sparing of motoneurons in the disease.
Obal
I
I
Department of Neurology, University of Szeged, Szeged, Hungary. obali@nucleus.szbk.u-szeged.hu
Siklós
L
L
Engelhardt
J I
JI
D000690:Amyotrophic Lateral Sclerosis / Q000276:immunology*; D000818:Animals; D002118:Calcium / Q000032:analysis* / Q000493:pharmacokinetics*; D004195:Disease Models, Animal; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016472:Motor Neuron Disease / Q000276:immunology*; D009046:Motor Neurons / Q000187:drug effects* / Q000276:immunology* / Q000648:ultrastructure; D013127:Spinal Nerves / Q000187:drug effects / Q000276:immunology / Q000648:ultrastructure
D007074:Immunoglobulin G; D002118:Calcium