Effect of exogenous ghrelin on body weight and hematocrit of male adult rats in chronic hypoxia

Background: Ghrelin is a peptide predominantly produced by the stomach. Recent studies have shown its protective roles and plasma alterations during hypoxia. Objectives: The aim of this study was to assess the effects of an exogenous administration of ghrelin on body weight and blood hematocrit during chronic hypoxia. Materials and Methods: Twenty four adult male Wistar rats were divided randomly into 3 groups. Hypoxic rats with saline or ghrelin treatment were placed in a normobaric hypoxic chamber for 2 weeks. Controls remained in room air. Weight gain, hematocrit, and plasma ghrelin were measured. Results: The rats showed significant (P < 0.05) weight loss in the hypoxic groups, and administration of ghrelin in hypoxic rats could prevent further weight loss. Interestingly, hypoxic animals that were treated with ghrelin were significantly more polycythemic than the controls and even the hypoxic rats treated with saline (P < 0.001). Plasma ghrelin significantly increased in the hypoxic animals at the end of the second week (P < 0.05). Conclusions: It seems that exogenous administration of ghrelin may be useful in modulating metabolism in high-altitude situations and that polycythemia induced by ghrelin, to some extent, might be a beneficial compensation during hypoxia. However, more investigation is needed to confirm the beneficial effects of ghrelin to establish this peptide’s status as a therapeutic agent. A R T I C L E I N F O Article history: Received: 12 Sep 2010 Revised: 5 Nov 2010 Accepted: 1 Jan 2011