Toxicity and Metabolism of Trimethylarsine in Mice and Hamsters

Toxicity and Metabolism of Trimethylaisinc in Mice and Hamsters.YAMAUCHI, H., KAISE, T., TAKAHASHI, K., AND YAMAMURA, Y. (1990).Fundam. Appl. Toxicol. 14, 399–407. Trimethylarsine (TM-As)proved to be an arsenic compound of low toxicity, with a poLD50 of 7870 mg/kg in mice. A single po dose of 10 mg/kg ofTM-As caused no hemolysis, but a single po dose of 750 mg/kginduced mild, transient hemolysis in hamsters. TM-As was veryrapidly eliminated into the urine, with a biological half-lifeof 3.7 hr. TM-As was oxidized In vivo to form trimethylarsineoxide (TMAO) and excreted as such into the urine. TM-As wasnever demethylated In vivo. A mechanism was demonstrated bywhich a part of TM-As was eliminated directly into the expiredair. We drew a conclusion that TM-As is far less toxic thanarsine, most probably due to its In vivo conversion to TMAO.c 1990 Society of Toxicology.