Thymosin α1 inhibits mammary carcinogenesis in Fisher rats

The effects of thymosin alpha(1) (Talpha(1)) on mammary carcinogenesis was investigated in Fisher rats. Mammary carcinomas were observed 3 months after N-nitrosomethylurea (NMU) injection (10 mg, i.p.) into Fisher rats. Daily administration of Talpha(1) (10 mug, s.c.) reduced mammary carcinoma incidence and prolonged survival time. Animals treated with exogenous Talpha(1) had a significantly greater blood white cell density than control Fisher rats. These results suggest that Talpha(1) prevents mammary carcinoma incidence as a result of stimulation of the immune system. (C) 2002 Published by Elsevier Science Inc.