The effects of growth hormone-releasing peptide-2 (GHRP-2) on the release of growth hormone and growth performance in swine

The effects of GHRP-2 (also named KP102), a new growth hormone-releasing pe ptide, on the release of growth hormone (GH) and growth performance were ex amined in swine. The single intravenous (i.v.) injection of GHRP-2 at doses of 2, 10, 30 and 100 mu g/kg body weight (BW) to cross-bred castrated male swine stimulated GH release in a dose-dependent manner, with a return to t he baseline by 120 min. The peak GH concentrations and GH areas under the r esponse curves (GH AUCs) for 180 min after the injections of GHRP-2 were hi gher (p < 0.05) than those after the injection of saline. The GH responses to repeated i.v. injections of GHRP-2 (30 mu g/kg BW) at 2-h intervals for 6 h were decreased after each injection. The chronic subcutaneous (s.c.) ad ministration of GHRP-2 (30 mu g/kg BW) once daily for 30 days consistently stimulated GH release. The CH AUCs for 300 min after the injections on d 1, 10 and 30 of treatment in GHRP-2-treated swine were higher than those in s aline-treated swine. However, chronic administration of GHRP-2 caused a par tial attenuation of GH response between d 1 and 10 of treatment. The chroni c s.c. administration of GHRP-2 also increased average daily gain for the e ntire treatment period by 22.35% (P < 0.05) and feed efficiency (feed/gain) by 20.64% (P < 0.01) over the saline control values, but did not significa ntly affect daily feed intake. These results indicate that GHRP-2 stimulate s GH release and enhancing growth performance in swine. (C) 2000 Elsevier S cience Inc. All rights reserved.