The differential toxicity of ammonium salts.

The relationship between liver disease and ammonia toxicity has been known since the discovery of meat intoxication in Eck fistula dogs (1-4). The similarity between this syndrome and clinical hepatic coma stimulated the study of ammonia toxicity in humans. This proceeded from oral administration (5-10) to intravenous infusion (11, 12) and finally to the development of an "ammonia tolerance test" (13, 14). Ammonia toxicity studies have been performed in animals by the intravenous (15-24), oral, subcutaneous, and intraperitoneal routes (25-29). Many different ammonium compounds were used in the above studies with the tacit assumption that their toxicities were similar. In order to test that assumption, intravenous LD50's were determined in mice under controlled conditions.