title: Fulminant hyperammonaemia induced by thiopental coma in rats.
abstract: Fulminant hyperammonaemia as a threshold effect of coma-inducing dose of sodium thiopental has been revealed in rats. Blood ammonia content increased progressively after the introduction of 1.0 LD(50) (but not 0.8 LD(50)) of sodium thiopental three times in 3h and five times in 18h. The urinary ammonia excretion was not impaired while the volatilization of ammoniac from the body of ST-treated rats was higher, giving evidence of the augmentation of ammonia production. Blood urea increased by one third despite of insignificant alterations of haematocrit and blood creatinine. Ammonia hyperproduction in the digestive tract could result from gastrointestinal stasis, which has been verified by roentgenography and confirmed by correlation of hyperammonaemia with the stool retardation. In thiopental coma rats the slope of a dose-dependent increase of the blood ammonia and the blood urea after the intraperitoneal injection of ammonium acetate did not exceed that in intact animals. So the ammonia hyperproduction in the digestive tract could be the main contributing cause of fulminant hyperammonaemia in rats with thiopental coma and thus be involved into pathogenesis of the coma.
authors.affiliation: Military Toxicology and Medical Protection, Military Medical Academy, ul. Lebedeva 6, 194044 St. Petersburg, Russia.
authors.forename: Jury Ju
authors.initials: JJ
authors.lastname: Ivnitsky
authors.forename: Vladimir L
authors.initials: VL
authors.lastname: Rejniuk
authors.forename: Timur V
authors.initials: TV
authors.lastname: Schäfer
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Malakhovsky
mesh_terms: D000085:Acetates / Q000008:administration & dosage / Q000633:toxicity; D000641:Ammonia / Q000097:blood; D000818:Animals; D001806:Blood Urea Nitrogen; D003128:Coma / Q000097:blood / Q000139:chemically induced*; D003672:Defecation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005766:Gastrointestinal Contents / Q000187:drug effects; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000503:physiopathology; D022124:Hyperammonemia / Q000097:blood / Q000139:chemically induced*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000633:toxicity; D007274:Injections, Intraperitoneal; D007415:Intestinal Obstruction / Q000097:blood / Q000139:chemically induced; D051381:Rats; D013874:Thiopental / Q000008:administration & dosage / Q000633:toxicity*; D013997:Time Factors
chemical_list: D000085:Acetates; D006993:Hypnotics and Sedatives; D000641:Ammonia; D013874:Thiopental; C018824:ammonium acetate