Histological and histochemical study of paraoxon myopathy in the rat.
Time and dose dependency of paraoxon-induced myopathy in rats was studied in relation to esterase inhibition and clinical symptoms. High-dose poisoning resulted in a major cholinergic crisis with concomitant acetylcholinesterase inhibition in the first few hours with rapid restoration thereafter. Dose-dependent segmental muscle fiber necrosis occurred in clusters around the end-plates and was more frequent in diaphragms as compared to gastrocnemius muscles. However, in low-dose poisoned rats without major cholinergic symptoms or end-plate cholinesterase inhibition, necrotic fibers were also present. This indicates that not only end-plate cholinesterase inhibition but also neural or neuronal factors might be responsible for acetylcholine overflow and muscle fiber degeneration.
De Bleecker
J
J
Neurology Department, University Hospital, Ghent, Belgium.
Willems
J
J
De Reuck
J
J
Santens
P
P
Lison
D
D
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004950:Esterases / Q000037:antagonists & inhibitors; D005260:Female; D008297:Male; D009132:Muscles / Q000187:drug effects* / Q000648:ultrastructure; D009135:Muscular Diseases / Q000139:chemically induced*; D010261:Paraoxon / Q000008:administration & dosage / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains
D004950:Esterases; D010261:Paraoxon