Role of muscle fasciculations in the generation of myopathies in mammalian skeletal muscle.
The myotoxicity of pyridostigmine bromide was investigated on rat diaphragm nerve-muscle preparations in vitro. Within 2 h of exposure to pyridostigmine (2 microM), diaphragm muscles exhibited ultrastructural alterations characterized by swelling of subjunctional mitochondria and disorganization of contractile proteins. These alterations developed both in the absence and presence of electrical stimulation of the phrenic nerve, and were accompanied by continuous muscle fasciculations. Pretreatment by tetrodotoxin suppressed both the muscle fasciculations and the appearance of myopathies. These findings suggest that fasciculations may be an important contributing factor in the development of anti-cholinesterase-induced myopathies.
Adler
M
M
Neurotoxicology Branch, U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010.
Hinman
D
D
Hudson
C S
CS
D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D003964:Diaphragm / Q000503:physiopathology; D004558:Electric Stimulation; D004594:Electrophysiology; D008297:Male; D008854:Microscopy, Electron; D009045:Motor Endplate / Q000187:drug effects; D009132:Muscles / Q000473:pathology* / Q000503:physiopathology; D009135:Muscular Diseases / Q000473:pathology* / Q000503:physiopathology; D011729:Pyridostigmine Bromide / Q000494:pharmacology; D051381:Rats; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology
D013779:Tetrodotoxin; D000110:Acetylcholinesterase; D011729:Pyridostigmine Bromide