NEUROPHARMACOLOGICAL ASSESSMENT OF GROWTH-HORMONE SECRETION

The biochemical diagnosis of individuals who are either deficient in g rowth hormone (GH) or who have alterations in the normal pattern of GH secretion is difficult. The uncertainty surrounding diagnosis reflect s the lack of a thorough understanding of the physiology of GH secreti on and of the hypothalamic hormones involved. At least three hormones are implicated: GH-releasing hormone (GHRH), somatostatin and the endo genous ligand of the GH secretagogue receptor, although the role that each plays in the release of GH is not clear from the available experi mental evidence. In such a situation, most of the dynamic tests of GH secretory capacity in humans need to undergo a 'trial and error' proce ss before being validated. The search for the 'gold standard' test of GH secretion is ongoing, and the combination of GHRH plus GK secretago gues will probably play an important role in future clinical diagnosis .