Tumorigenicity of tetramethylhydrazine hydrochloride in Swiss mice.

Tetramethylhydrazine hydrochloride (TEMH) was administered in drinking water as a 0.125% solution to randomly bred Swiss mice for life beginning at 6 weeks of age. As a result of treatment, the incidence of blood vessel tumors rose from 5 to 96% in females and from 6 to 88% in males, while that of lung tumors increased from 21 to 36% in females and from 23 to 28% in males, as compared with untreated controls. The increased incidence of blood vessel tumors, but not of lung neoplasms, was statistically significant. Histopathologically, the tumors exhibited the characteristics of angiomas and angiosarcomas of blood vessels and adenomas of the lung. The investigation proved for the first time the tumorigenicity of TEMH. The possible role of increased methyl substitution on hydrazine in tumorigenesis was also discussed, as well as hydrazine derivatives as a tumor-producing class.