Growth Hormone and Insulin Release After Arginine: Indifference to Hyperglycemia and Epinephrine

Attention has centered primarily on changes in blood glucose concentration as a mediator of insulin and growth hormone (HGH) release. Hypoglycemia, however produced, calls forth an outpouring of HGH, and hyperglycemia is followed by a rise in plasma insulin (1, 2). More recently, infusion of several amino acids including arginine has been shown to provoke the release of both insulin and HGH (3–6). It has not been established whether glucose-initiated and amino acid-initiated hormonal release is mediated by separate mechanisms, a question which may assume importance in human disease since it is hypothetically possible that an endocrine gland may become insensitive to one stimulus, while retaining responsiveness to another.