EFFECTS OF GROWTH HORMONE ON METABOLIC AND ENDOCRINE FACTORS IN HYPOPHYSECTOMIZED DOGS

Abstract

Hypophysectomy in dogs caused reductions in: the level of sugar in the blood; the volume % of packed red blood corpuscles; the rate of clearance of bromsulphthalein; the weight of the pancreas; the amount of insulin extractable from the pancreas; and the weights of the kidneys, heart, and adrenal glands. The glucose tolerance of hypophysectomized dogs was significantly less than that of normal dogs.The administration of growth hormone during 5 days to hypophysectomized dogs caused: increase of blood sugar but not to diabetic levels; elevation and prolongation of the glucose tolerance curve; increased erythrocyte sedimentation rate; reduced volume % of red blood corpuscles; restoration of bromsulphthalein clearance to normal; reduction of the insulin extractable from the pancreas to 60% of the pretreatment level; increases in the weight, total lipid, dry fat-free residue, and water of the liver; and restoration of the kidney weight and lipid content to normal. Little or no glycosuria or ketonuria and no anorexia occurred under these conditions.The same treatment of normal dogs with growth hormone caused: increase of blood sugar to diabetic levels; elevation and prolongation of the glucose tolerance curve; increased erythrocyte sedimentation rate; decreased volume % of packed red blood corpuscles, glycosuria, ketonuria, albuminuria, and anorexia; great decrease in the amount of insulin extractable from the pancreas to 6% normal; increase in the total lipid, dry fat-free residue, and water of the liver, increase in the weight and lipid of the kidney; and increase in the weight of the ventricles of the heart. The bromsulphthalein clearance was not altered. The physiological significance of these findings is discussed, particularly the production by growth hormone of more pronounced diabetes and greater reduction of insulin extractable from the pancreas in normal than in hypophysectomized dogs.