The Influence of Immunosuppression and Sex Hormone Manipulation on Mammary Tumounrogensis in Rat

Abstract

Summary The 7.12 dimethyl benznthracene induced rat mammary tumour model was chosen as system for the investigation of the effect of sex hormone and immunosuppression on later incidence of tumours. Prior oophorectomy significantly reduced tumour incidence. No increase in tumour incidence after immunosuppression with antithymocyte globulin was shown unless the rats were previously oophorectomised. Subsequent treatment with oestradiol restored the carcinogenic action of 7‐12 dimethyl benzanthracene in oophorctomised animals and testosterone inhibited tumour development in oophorectomised, immunosuppressed rats.

Effects of Reserpine on the Incidence of 9,10-Dimethyl-1,2-benzanthracene-induced Tumors in Pinealectomised and Thymectomised Rats

“…3. The immune-suppression due to neonatally performed ThX does not increase susceptibility to the carcinogenic effect of DMBA, which corresponds with the results of Hunt and Holyoke [8]. The findings of nephroblastoma ob served in two ThX animals correlates with the findings of such tumors in rats treated with DMBA and antilymphocytic serum [3].…”