Induction of Permanent Diabetes in Rats by Pituitary Hormones from a Transplantable Mammotropic Tumor. Concomitant Changes in Organ Weights and the Effect of Adrenalectomy

Abstract

No diabetes was observed in rats after 80% of the pancreas was removed (80 [image]) or in unoperated rats bearing large transplantable mammotropic pituitary tumors (MtT) that produce very high blood levels of 3 dlabetogenic hormones, growth hormone, prolactin and ACTH (adrenocorticotropic hormone). Diabetes developed in 32 of 33 rats that were 80% [image] and had MtT; in 8 of 9 rats that were 65% [image] and had MtT; and in only 3 of 11 rats that were 40% [image] and had MtT. The persistence of the diabetic state (blood sugar 300-400 mg/ 100 ml) in 80% [image] rats for 3 weeks after surgical removal of the MtT was demonstrated. Typical diabetic histological changes were observed in the [beta]-cells. Adrenalectomy of 80% [image] rats with MtT prevented the development of diabetes in about half of the rats. The other half had only mild diabetes. The usual growth-producing effect of MtT was inhibited by 80% [image] in intact rats which became diabetic but was not inhibited by 80% [image] in adrenalectomized rats; 80% [image] had no effect on organ weights of rats with or withoug MtT unless diabetes developed. Diabetes led to an increased food intake with a concomitant increase in the length and weight of the intestine.