Effects of Stress on Growth of Transplanted and 7,12-Dimethylbenz[ a ]anthracene-Induced Tumors and Their Modification by Psychotropic Drugs 2

Abstract

The effects of various types of stress (immobilization, sound, electric foot-shock, and electroconvulsive shocks) on the growth of transplanted 4M mammary carcinoma in Sprague-Dawley male littermate rats and 7,12-dimethylbenz[a]anthracene-induced tumors in Sprague-Dawley female Iittermate rats were investigated. Growthof these tumors was inhibited concomitant with an increase in adrenal weight and decrease in spleen weight. Pretreatment with chlorpromazine reduced or abolished the inhibition of tumor growth in the stressed rats. Neuroendocrine and other mechanisms appeared to be involved in such effects.