Roentgen Irradiation of the Hypophysis

Abstract

IN view of the increased interest in the pituitary body in relation to experimental and clinical endocrinology, and because of the frequent attempts to influence disease through irradiation of the adenomatous or non-adenomatous gland, it has seemed important to study the effects of irradiation of the normal pituitary body of the white rat. During the past twenty years there have been numerous reports on the effects of irradiation of the hypophysis for various gynecological conditions, with varying results. Recently, irradiation of the pituitary has been extended to patients with diabetes mellitus and so-called essential hypertension, again with varying results. The question naturally arises, can the non-adenomatous pituitary gland be influenced with therapeutic doses of x-rays? A partial answer to this question could probably be obtained through animal experimentation. Apparently the first studies on the effects of pituitary irradiation in animals were made by Strauss (1) and Brunner (2), working independently in 1920. Strauss noted histologic changes in the pituitary body of the guinea pig after irradiation, but no changes in the other endocrine glands. Brunner irradiated the whole heads of young cats and puppies, and in addition to very slight histologic changes in the nervous tissue he found some histologic changes in the anterior pituitary. There was some suppression of growth after irradiation. Fraenkel and Geller (3), in 1921, irradiated the pituitary regions of young female rabbits. The irradiated animals grew less rapidly than the controls, and when killed they showed definite under-development of the genital organs, including small uteri and small ovaries with infantile follicles. The pituitary bodies of the experimental animals were small, and many of the cells in the anterior and middle lobes had indistinct boundaries and contained irregular pyknotic nuclei. There was, however, no characteristic change in any particular cell. In 1922 Rahm (4) irradiated the hypophyseal regions of young rabbits. With smaller doses he noted stimulation of growth, and larger doses caused cessation of growth. There were no histologic studies. Ghilarducci (5) also used young rabbits and claims to have found that many animals died after irradiation. At autopsy the internal organs were normal but there were skeletal changes with deformity, and complete destruction of the anterior pituitary glands, but apparently no changes in the ovaries or other endocrine glands. Podljaschuk, in 1927 and 1928 (6-a and 6-b), using young and mature rabbits and dogs, and giving more than an erythema dose to the pituitary region, observed inconstantly, suppression of growth, and under-development of sex organs with histologic changes in the pituitary body. Del Buono (7), using slightly less than a skin dose in adult dogs, could demonstrate no structural changes in the hypophysis or other organs, six months to one year after irradiation.