title: Measures of skeletal muscle calcium channels and acetylcholine receptors in thyroidectomized rats.
abstract: Hypothyroidism frequently presents with muscle complaints. No consistent histopathology nor electrophysiology explains these symptoms and signs. As well, no previous study shows specific changes in components of the nerve-muscle synapse nor excitation-contraction coupling in adult muscles, but changes are seen in hormone-treated embryonic myoblasts. In this study, adult male Holtzman rats underwent thyroidectomy and their age-matched euthyroid controls were simultaneously subjected to sham operation. Thirty days post-operative, animals were sacrificed for anterior tibialis muscles harvest. Muscle dihydropyridine type calcium channel (isradipine) and acetylcholine receptor (alpha-bungarotoxin) binding were measured and compared between experimental treatment groups. There were no significant differences in either the affinity or density of isradipine binding. However, hypothyroid muscles showed a nearly 50% reduction in acetylcholine receptor density when compared to control muscles. Thyroidectomy is associated with specific effects on components of neuromuscular transmission in adult fast twitch muscle.
authors.affiliation: Department of Biological Sciences, Faculty of Natural Sciences and Mathematics, State University of New York at Buffalo 14260.
authors.forename: L
authors.initials: L
authors.lastname: Kragie
authors.forename: R
authors.initials: R
authors.lastname: Smiehorowski
mesh_terms: D000818:Animals; D002038:Bungarotoxins / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism*; D007037:Hypothyroidism / Q000378:metabolism*; D017275:Isradipine / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000378:metabolism*; D013965:Thyroidectomy
chemical_list: D002038:Bungarotoxins; D015220:Calcium Channels; D011950:Receptors, Cholinergic; D017275:Isradipine