title: Systemic administration of oxytocin reduces basal and lipopolysaccharide-induced ghrelin levels in healthy men.
abstract: Oxytocin (OXT) and ghrelin have several common properties such as the involvement in the first phase response to stressors, in appetite regulation, and in the modulation of neural functions. Despite a recent study showing that intraventricular administration of ghrelin activates OXT neurons, little is known on the cross-talk between these two peptides. Here, we investigated the role of the i.v. administration of OXT on circulating ghrelin concentrations under fasting conditions and during the lipopolysaccharide (LPS)-induced endotoxemia. A randomized placebo-controlled cross-over study was performed in ten healthy men. In four study sessions, the participants received once placebo, once OXT (1 pmol/kg per min over 90 min), once LPS (2 ng/kg), and once both OXT and LPS. Plasma ghrelin, glucose, and free fatty acid (FFA) levels were measured at regular intervals during the first 6 h following the LPS bolus. Systemic administration of OXT decreased within 1 h plasma ghrelin levels (611+/-54 vs 697+/-52 pg/ml in placebo days, P=0.013) and increased plasma glucose and FFA concentrations (P=0.002 and P=0.005 respectively). OXT also reduced the LPS-induced surge in ghrelin at time point 2 h (P=0.021). In summary, i.v. administration of OXT decreases circulating levels of ghrelin during fasting, as well as following LPS-induced endotoxemia in healthy men. The cross-talk between OXT and ghrelin might be important in the regulation of energy homeostasis and stress responses.
authors: Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. greisa.vila@meduniwien.ac.at
authors: Greisa
authors: G
authors: Vila
authors: Michaela
authors: M
authors: Riedl
authors: Michael
authors: M
authors: Resl
authors: Aart Jan
authors: AJ
authors: van der Lely
authors: Leo J
authors: LJ
authors: Hofland
authors: Martin
authors: M
authors: Clodi
authors: Anton
authors: A
authors: Luger
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D019446:Endotoxemia / Q000097:blood*; D005215:Fasting / Q000097:blood*; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D010121:Oxytocin / Q000008:administration & dosage / Q000097:blood*; D013312:Stress, Physiological; D055815:Young Adult
chemical_list: D054439:Ghrelin; D010121:Oxytocin