A comparative study of serum growth hormone and plasma cortisol levels in stimulation tests with insulin and propranolol-glucagon.
Insulin and propranolol-glucagon stimulation tests were carried out on 28 children and 5 adolescents and the results of their growth hormone and plasma cortisol estimations were compared. Twenty-nine subjects with normal growth hormone reserves showed a mean maximum rise of 17.4 muU/ml of serum growth hormone in the insulin test whereas the intramuscular injection of glucagon after oral premedication with propranolol produced a rise of 38.5 muU/ml. Five subjects with normal growth hormone reserves showed a reduced hormone output in the insulin stimulation tests but normal response in the propranolol-glucagon stimulation tests. Only one subject showed a poor response in the propranolol-glucagon but normal response in the insulin stimulation test. In 30 subjects with normal adrenocortical function the mean maximum increase of plasma cortisol was 15.6 muU/ml in the insulin - and 14.9 muU/ml in the propranolol-glucagon stimulation tests, respectively. Both methods are suitable for studying the pituitary-adrenocortical interrelationships. The mechanism of the release of glucagon-induced growth hormone is not clear but the fall in blood glucose does not seem to play a major role in the process. A stress-like mechanism is equally unlikely because vegetative symptoms occurred only i a small number of subjects after intramuscular glucagon administration. It is possible that glucagon possesses a releasing-like mechanism which operates in the pituitary itself.
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D005934:Glucagon / Q000494:pharmacology*; D006130:Growth Disorders / Q000097:blood; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology*; D011292:Premedication; D011433:Propranolol / Q000494:pharmacology*; D013268:Stimulation, Chemical
D001786:Blood Glucose; D007328:Insulin; D013006:Growth Hormone; D005934:Glucagon; D011433:Propranolol; D006854:Hydrocortisone