Effect of atropine on cyanide-induced acute lethality in mice.
The effects of atropine on acute lethality induced by cyanide were investigated in mice. The LD50 value of cyanide (s.c. injection) was 8.4 (7.6-9.3) mg/kg. However, the LD50 value of cyanide (s.c.) was significantly increased by 1.5-fold when atropine (32 mg/kg) was injected s.c. in mice. Furthermore, the combined administration of atropine (32 mg/kg), Ca2+ (500 mg/kg) and sodium thiosulfate (1 g/kg) tremendously increased the LD50 value by 5.6-fold in mice although sodium thiosulfate or Ca2+ alone increased the LD50 2.5- or 1.5-fold. On the other hand, although the LD50 value of cyanide (intracerebroventricular injection (i.v.t.)) was 52.0 (47.4-57.0) micrograms/brain, the LD50 value of cyanide (i.v.t.) was significantly increased by 1.3- or 1.61-fold in mice 10 min after s.c. injection of atropine (32 mg/kg) or Ca2+ (500 mg/kg). Furthermore, the combined administration of atropine and Ca2+ increased the LD50 value of cyanide by 2.1-fold. These results suggest that atropine inhibits cyanide-induced acute lethality and promotes the antagonistic effect of thiosulfate and Ca2+ in mice.
D000818:Animals; D001285:Atropine / Q000008:administration & dosage / Q000494:pharmacology*; D002118:Calcium / Q000008:administration & dosage / Q000494:pharmacology; D003486:Cyanides / Q000097:blood; D004347:Drug Interactions; D007276:Injections, Intraventricular; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D011190:Potassium Cyanide / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D013885:Thiosulfates / Q000008:administration & dosage / Q000494:pharmacology
D003486:Cyanides; D013885:Thiosulfates; D001285:Atropine; C017717:sodium thiosulfate; D011190:Potassium Cyanide; D002118:Calcium