Growth hormone secretagogues: The clinical future

Growth hormone (GH) releasing hexapeptide (GHRP)-6 and other peptidergic an d non-peptidergic compounds collectively designated GH secretagogues (GHS) are potent releasers of GH in man. Their clinical future may be envisioned in th ree areas: therapy of GH-deficient (GHD) states, diagnosis of GHD, an d non-endocrinological actions, As therapeutic agents and compared with GH itself, GHS have the disadvantage of lower potency but have a more physiolo gical and safer profile of GH secretion. GHS administration could be indica ted for states in which medium GH doses have been shown to be effective. As a diagnostic tool, the combined administration of GH releasing hormone plu s GHRP-6, both at saturating doses, is currently the most powerful releaser of GH, devoid of side effects and convenient for the patient; it may also be an alternative to the insulin tolerance test for the diagnosis of GHD in adult patients. Their potential action at cardiovascular level is highly p romising. Although the clinical future of GH releasing substances is appeal ing, probably the most relevant contribution has yet to be discovered. Once the endogenous ligand of the GHS receptor is identified, we will have an i nsight into the real hypothalamic control of GH secretion in man. With this knowledge it is likely that some diagnostic and therapeutic actions that a re commonly undertaken will significantly change. Copyright (C) 1999 S. Kar ger AG, Basel.