ALPHA-LACTALBUMIN CONTENT OF RAT MAMMARY CARCINOMAS AND EFFECT OF PITUITARY STIMULATION

Abstract

Primary mammary carcinomas induced in nonlactating rats by 7,12-dimethylbenz(.alpha.)anthracene or methylnitrosourea contained .alpha.-lactalbumin (.alpha.LA) in quantities equal to or < 10% of the amounts found in the parenchyma of the 5 day lactating gland. Only 2 of 5 transplantable mammary carcinomas contained .alpha.LA when growing in rats without hormonal stimulation. Hormonal stimulation maintained by transplantation into lactating females for 146 generations (65 mo.) failed to induce .alpha.LA production in dimethylbenz(.alpha.)anthracene no. 1 transplantable mammary carcinoma. Transplantation of a pituitary gland under the kidney capsule of the host increased .alpha.LA content of primary dimethylbenz(.alpha.)anthracene induced mammary carcinomas, reduced .alpha.LA content of primary methylnitrosourea induced mammary carcinomas and was unable to modify the .alpha.LA levels in 5 transplantable mammary carcinomas.