Effects of ghrelin on plasma glucose levels, body weight, food intake and hematocrit in acute and chronic systemic hypoxia in adult male rats

Abstract

Introduction: Acute and chronic hypoxia influence blood glucose levels and decrease body weight. Ghrelin increases appetite and body weight and regulates energy metabolism and also glucose homeostasis. Therefore, in the present study the effects of ghrelin administration on blood glucose, body weight, food intake and hematocrit were investigated in a model of systemic normobaric acute and chronic hypoxia in adult male rats. Materials and methods: Forty-eight adult male Wistar rats were divided into six groups [acute control + saline, chronic control + saline, acute or chronic hypoxia + saline, acute or chronic hypoxia + ghrelin (80 +g/kg/day, ip)]. Control groups remained in room air (21% O2) and hypoxia (11% O2) induced by a normobaric hypoxic chamber for two days (acute) or ten days (chronic). Blood glucose levels, body weight, food intake and hematocrit were assessed. Results: Chronic hypoxia caused a significant (P<0.001) decrease in blood glucose levels. Administration of ghrelin increased blood glucose levels significantly in acute (P<0.05) and chronic (P<0.01) hypoxia. Body weight decreased (P<0.001) in both acute and chronic hypoxic groups. Administration of ghrelin could (P<0.001) prevent decrease in body weight in chronic hypoxia group. Acute and chronic (P<0.001) hypoxia significantly decreased food intake. Ghrelin however increased food intake in both the acute (P<0.001) and chronic (P<0.05) hypoxia groups. Acute (P<0.01) and chronic (P<0.001) hypoxia also increased hematocrit. Conclusion: Ghrelin administration is useful in modulating blood glucose, body weight and food intake in hypoxic situations.