Species susceptibility to the pulmonary toxicity of 3-furyl isoamyl ketone (perilla ketone): in vivo support for involvement of the lung monooxygenase system.

To explore a possible relationship between metabolism and lethality, the acute toxicity of naturally occurring perilla ketone (PK), 1-(3-furyl)-4-methyl-pentan-1-one, was examined in the uninduced mouse, hamster, rabbit, dog and pig. The LD50 (+/- SE), determined using intraperitoneal (ip) injection, for the mouse and hamster were low at 5.0 +/- .3 and 13.7 +/- .9 mg/kg, respectively. The rabbit died from an ip dosage of near 14 mg/kg and estimated ip LD50 dosages were quite high for the dog and pig, being 106 +/- 25 mg/kg and over 158 mg/kg, respectively. Dogs and the pig that died from ip injections of PK displayed varying degrees of midzonal and centrilobular liver damage and dogs also had elevated serum alkaline phosphatase and glutamic-pyruvic transaminase activities. In contrast, rodents and rabbits display only pulmonary toxicity from this agent. Cytochromes P-450 and b5 concentrations and NADPH-cytochrome c reductase activity were determined for the lung, liver and kidney of mice, hamsters, rabbits, dogs, swine, sheep and cattle. High correlation between lethality and enzyme concentration further supports the hypothesis that enzymatic bioactivation of PK is required for toxicity in all species.