ABSTRACT
The resistance of puppies to the diabetogenic effect of administered growth hormone is well known. The possibility that this involves an adaptive increase in insulin secretion was explored by determining the effect of injected growth hormone on plasma insulin concentration at various age periods. Bovine growth hormone (1 mg/kg per day for 4 days) administered to 5-month-old puppies had no effect on plasma glucose or insulin levels nor on the effectiveness of injected insulin to lower plasma glucose levels. At 8 and 12 months of age the growth hormone regimen increased plasma glucose and insulin levels and produced a resistance to the hypoglycemic effect of injected insulin. It is evident that the difference between the puppy and adult in response to growth hormone is not due to excessive secretion of insulin by the puppy.