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Altered muscle calcium channel binding kinetics in autoimmune motoneuron disease
Author(s) -
Smith R. Glenn,
Kimura Fumiharu,
Harati Yadollah,
McKinley Kevin,
Stefani Enrico,
Appel Stanley H.
Publication year - 1995
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880180609
Subject(s) - skeletal muscle , amyotrophic lateral sclerosis , endocrinology , medicine , voltage dependent calcium channel , calcium channel , dihydropyridine , calcium , denervation , myasthenia gravis , chemistry , biology , disease
While skeletal muscle is not apparently affected directly in amyotrophic lateral sclerosis (ALS), immunoglobulin G fractions purified from patients with ALS (ALS IgG) bind dihydropyridine (DHP)‐sensitive L‐type voltage‐gated calcium channel (VGCC) antigen isolated from skeletal muscle in ELISA and Western immunoblot, and alter VGCC function in vitro. To determine whether muscle VGCC properties are altered in ALS, VGCC‐enriched subsarcolemmal membrane fractions were prepared from biopsied quadriceps muscle of patients with ALS, with other neurologic diseases, or without apparent muscle disease, and tested for DHP binding with [ 3 H]PN200‐110. ALS muscle VGCCs from muscle fractions of most other patients, independent of denervation‐induced increases in DHP binding site number. Similarly elevated DHP binding affinities were observed in specimens from patients with autoimmune motor neuropathies, suggesting that ALS and immunemediated motoneuron disease share skeletal muscle L‐type VGCC alterations. © 1995 John Wiley & Sons, Inc.