Convulsions induced by canatoxin in rats are probably a consequence of hypoxia.
Canatoxin, a convulsant neurotoxin from the seeds of Canavalia ensiformis, induces lipoxygenase-dependent hypoxia and sex-related alterations of carbohydrate metabolism in rats which are blocked by glucose, diazepam and hexamethonium. The present study analyzes the possible casual relationship between the convulsant action of canatoxin and its effects on carbohydrate metabolism. The incidence of canatoxin-induced convulsions was greater in male than in female rats. Pretreatment of male rats with drugs that block hypoxia, such as glucose (2.5 g/kg, iv, 15 min), diazepam (5 mg/kg, ip, at 48 h, 24 h and 15 min), hexamethonium (4 mg/kg, ip, 15 min) and NDGA (125 mg/kg, ip, 1 h), also protected the animals against convulsions, respiratory distress and death. These results suggest that canatoxin-induced convulsions are probably the consequence of hypoxia and both effects are mediated by lipoxygenase activation.
Ribeiro-DaSilva
G
G
Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Brasil.
Pires-Barbosa
R
R
Prado
J F
JF
Carlini
C R
CR
D000818:Animals; D001219:Aspartate Aminotransferases / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D000860:Hypoxia / Q000139:chemically induced* / Q000150:complications; D007773:Lactates / Q000378:metabolism; D037102:Lectins / Q000633:toxicity*; D007928:Lethal Dose 50; D008084:Lipoxygenase / Q000378:metabolism*; D008099:Liver / Q000187:drug effects; D008112:Liver Glycogen / Q000378:metabolism; D008297:Male; D010940:Plant Proteins; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000209:etiology*; D014118:Toxins, Biological
D001786:Blood Glucose; D007773:Lactates; D037102:Lectins; D008112:Liver Glycogen; D010940:Plant Proteins; D014118:Toxins, Biological; C032815:canatoxin; D008084:Lipoxygenase; D001219:Aspartate Aminotransferases