| dc.description.abstract | Hypoxia is an important pathogenic factor for the induction of vascular leakage and brain edema formation. Recent studies suggest a role for TNF-alpha in the induction of brain edema. Ghrelin attenuates the synthesis of TNF-alpha following subarachnoid hemorrhage and traumatic brain injury (TBI). Therefore, we examined the effects of ghrelin on the brain edema, serum TNF-alpha levels and body weight in a systemic hypoxia model. Adult male Wistar rats were divided into acute and chronic controls, acute or chronic hypoxia and ghrelin-treated (80 mu g/kg/ip/daily) acute or chronic hypoxia groups. Systemic hypoxia was induced in rats by a normobaric hypoxic chamber (O-2 11%) for two days (acute) or ten days (chronic). Effect of ghrelin on brain edema and serum TNF-alpha levels was assessed by dry wet and ELISA method, respectively. The results showed that acute (P < 0.001) and chronic (P < 0.05) hypoxia caused an increase of brain water content. Administration of ghrelin only in the acute hypoxia group significantly (P < 0.001) reduced brain water content. Acute hypoxia caused an increase of serum TNF-alpha level (P < 0.001) and ghrelin significantly (P < 0.001) reduced it. TNF-alpha level in chronic hypoxia did not change significantly. Both acute and chronic hypoxia decreased body weight significantly (P < 0.001) and administration of ghrelin only could prevent further weight loss in chronic hypoxia group (P < 0.001). Our findings show that administration of ghrelin may be useful in reducing brain edema induced by acute systemic hypoxia and at least part of the anti-edematous effects of ghrelin is due to decrease of serum TNF-alpha levels. (C) 2013 Elsevier Ireland Ltd. All rights reserved. | |
