An environmental androgen, 17beta-trenbolone, affects delayed-type hypersensitivity and reproductive tissues in male mice.

Recently, a growth promoter for farm animals, trenbolone acetate, was identified as an environmental androgen that potentially affects reproduction. Because androgens also suppress immunity, it was hypothesized that an active metabolite of trenbolone acetate, 17beta-trenbolone (TB), might impair immune responses. Castrated adult CD-1 mice were injected daily with either one of two different doses of 17beta-trenbolone (TB), testosterone propionate (TP), or corn oil (vehicle). The antigen-specific immune response was assessed by measuring delayed-type hypersensitivity (DTH) responses. Reproductive response was assessed by measuring reproductive tissue mass and determining testosterone concentrations. Mice treated with TB or TP displayed larger reproductive tissue mass than males treated with corn oil. Furthermore, males exposed to the highest dose of TB displayed a reduced DTH response compared to vehicle-treated animals. In comparison, TP, at a similar dose, only minimally reduced the DTH response. These data support the reproductive and potentially immunosuppressive effects of this environmental androgen, and raise the possibility of health concerns for individuals or populations in contact with high concentrations of TB.