The Effect of Hypophysectomy upon the metabolism of Grafted Tumor Tissue

Abstract

Numcrous attempts havc bccn made to establish a relationship between the pituitary gland and tumor growth. Zondek and his coworkers (1) and Cannavo ( 2 ) concluded from their experimental work that the growth of graftcd tumors could be inhibited or retarded by injections of prolan. This could not be confirmed by Krehbiel, Haagensen, and Plantenga ( 3 ) , nor by Suginra and Benedict (4), nor by Wiesncr and Haddow (5). Gross ( G ) , on the other hand, observed slightly accclerated growth in mouse sarcoma when using comparatively small doses of prolan ; and BischofT and his co-workers (7) found that standardized growth-promoting preparations of the pituitary significantly accclerated the ratc of growth of carcinoma 256 in older rats. Bischoff and his associates (7) also found that pituitary irradiation retarded the growth rate of grafted tumors in rats and mice. Ball, Samuels, and Simpson (8, 9) reported a smaller percentage of takes and a retardation of growth of the Walker transplantable mammary carcinoma in hypophysectomized rats. McEuen and Thomson (10) found that hypophysectomy retarded but did not prevent the growth of the Walker rat tumor, and also found that semi-starvation, similar to that which obtains in hypophysectomized rats, resulted in a retardation of tumor growth equivalent to that produced by hypophysectomy.No study appears to have been made, however, of the effect of removal of the pituitary gland upon the metabolism of transplanted tumor tissue. Studies of tumor tissue metabolism in mice after removal of the testicles, thyroid glands, and suprarenal glands have been reported by Meyer, McTiernan, and Rub (11). Since hypophysectomy has been shown to induce a lowering of general body metabolism (12), an investigation was made to see whether this effect also obtained in the metabolism of transplanted tumor tissue in the rat. hf ETHODSFourteen inbred, pure-strain, albino, male rats were hypophysectomized by the parapharyngeal route when their weights were between 80 and 100 grams. Litter-mate controls were set aside. Between two and four wceks after operation when, by stationary body weight and atrophy and retraction of the testiclcs, it became obvious that complete hypophysectomy had been effected, tumor transplants of the Walker rat carcinoma No. 256 were placed beneath the skin of both flanks. The tumors had usually reached sufficient size in both the hypophysec-106

The Relation of the Hypophysis to the Growth of Malignant Tumors: IV. A Study of the Influence of Nutritional Factors on Walker Tumor 256 in Relation to the Effect of Hypophysectomy

“…Since pituitary ablation has been shown to influence the rate of growth of transplanted (1)(2)(3)(4) and autogenous (5) rat tumors, several investigators (6,7,8) have made an effort to define the factors by which this effect is produced. The numerous physiologic and anatomic changes which follow hypophysectomy contribute to make the problem complex.…”