Proton hypophysectomy and induction of mammary gland carcinoma

It is shown that irrespective of the size of the damaged part of the hypophysis after single irradiation with a narrow beam of protons with doses of 15000-30000 rad no tumours of the mammary gland developed in most of the rats, whereas in the control group they appeared in 81 per cent of the animals. There were but inconsiderable variations in the mass index of the ovaries, adrenals and the uterus in the animals with partial or complete damage of the hypophysis. These data confirm the observations according to which the clinical effect of hypophysectomy is determined not only by the complete damage of the hypophysical tissue. Possibilities of selective exclusion of certain structures of the hypophysis pertaining to regulation of the mammary gland proliferative and functional activity by means of ''bloodless'' destruction are discussed