Importance of Thyroid Hormone and Testosterone in the Induction of Carcinoma and Cirrhosis of the Liver in Female Wistar Rats Ingesting N-2-Fiuorenyldiacetamide23

Abstract

Female Wistar rats were given 0.025 percent N-2-fluorenyldiacetamide, a hepatocarcinogen, in the diet, and the relationship of the thyroid to the adrenals and to sex and sex hormones in carcinogenesis and cirrhosis of the liver was evaluated. Intact, thyroidectomized, adrenalectomized, castrated, thyroidectomized-castrated, and adrenalectomized-castrated female animals fed the carcinogen-containing diet failed to develop tumors or cirrhosis of the liver. Exogenous thyroid hormone did not induce hepatic carcinomas in any of the animals. Testosterone propionate was not effective when administered alone to thyroidectomized or thyroidectomized-castrated animals, but when given simultaneously with thyroid hormone, tumors and cirrhosis of the liver did develop in female animals. Thyroid hormone and testosterone propionate are necessary for the induction of carcinomas and cirrhosis of the liver in both male and female rats.