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.

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doi.org/10.1677/JOE-09-0227, hdl.handle.net/1765/17851
Journal of Endocrinology
Erasmus MC: University Medical Center Rotterdam

Vila, G., Riedl, M., Resl, M., van der Lely, A.-J., Hofland, L., Clodi, M., & Luger, A. (2009). Systemic administration of oxytocin reduces basal and lipopolysaccharide- induced ghrelin levels in healthy men. Journal of Endocrinology, 203(1), 175–179. doi:10.1677/JOE-09-0227