Prevention of Ulcer Formation by Hypophysectomy

Hypophysectomy in the rat reduced gastric ulcers induced by administration of prednisolone for 4 days. Ulcer inhibition became more marked as the interval between hypophysectomy and treatment with prednisolone increased. Seventeen weeks after hypophysectomy, the animals were almost completely resistant to ulcerations. This slowly developing refractoriness was not accompanied by resistance to other properties of prednisolone; thus, body weight loss and spleen atrophy produced by the corticoid were maximal already one week after hypophysectomy and remained so throughout the 17 weeks of the experiment. Pituitary-dependent structures (adrenals, thyroid, testes) were previously reported to be maximally involuted within a month following hypophysectomy. To interpret this unique effect of hypophysectomy, it is suggested that either a humoral factor, of unknown origin, endowed with anti-ulcer activity, may be formed in progressively increasing amounts after removal of the pituitary or that the peripheral effects of the secretion of some pituitary-dependent gland(s) persist for variable intervals after hypophysectomy. The possible protective role of corpora lutea, persisting after hypophysectomy, is also considered.