Effects of central infusion of ghrelin on food intake and plasma levels of growth hormone, luteinizing hormone, prolactin, and cortisol secretion in sheep

Abstract

Ghrelin is an endogenous ligand for the GH secretagogue/ghrelin receptor (GHS-R) and stimulates feeding behavior and GH levels in rodents and humans. A preprandial increase in plasma ghrelin levels is seen in sheep on programmed feeding, followed by a postprandial rise in plasma GH levels, but effects on food intake and endocrine function are not defined in this ruminant species. We administered ghrelin to female sheep in various modes and measured effects on voluntary food intake (VFI) and plasma levels of GH, LH, prolactin, and cortisol. Whether administered intracerebroventricularly or iv, ghrelin consistently failed to stimulate VFI. On the other hand, ghrelin invariably increased plasma..