PERIPHERAL TOXICITY OF HEMICHOLINIUM‐3 IN MICE

1 The site (i.e. peripheral or central) of the toxicity produced by hemicholinium‐3 in mice was investigated. 2 Hemicholinium‐3 was measured fluorometrically and acetylcholine was determined by gas chromatography after intraventricular or intraperitoneal administration of hemicholinium‐3. 3 Hemicholinium‐3 was not detected in the brain nor were acetylcholine levels decreased in the brain after systemic administration. 4 The dose‐response curve following intraventricular administration demonstrated that hemicholinium‐3 was not as lethal after central administration as it was after peripheral administration. 5 Approximately 24% of a 75 μg intraventricular dose of hemicholinium‐3 was found in the periphery at death. 6 These results suggest that hemicholinium‐3 manifests its toxicity primarily in the periphery.