Ghrelin has been reported to cause hyperglycemia in humans and adiposity in rodents. The objective of trial one was to test the effects of ghrelin on blood and body composition in rats. The objective of trial two was to evaluate the effect of two doses of ghrelin on blood and body composition. Trial One: Adult male Sprague Dawley rats were administered 1 μg/rat ghrelin in 0.15 M NaCl or vehicle (0.15 M NaCl) every morning for 30 days. The terminal blood sample was analyzed for glucose, urea nitrogen, and nonesterified fatty acids concentrations. The carcasses were analyzed for total lipid and nitrogen content. Blood urea nitrogen, nonesterified fatty acids, carcass total lipid, and carcass total nitrogen concentrations were similar for the control and ghrelin groups. However, blood glucose concentration tended to be higher in the ghrelin group than in the control. Ghrelin administered at 2.4 μg/kg did not cause adiposity in rats but did tend to cause hyperglycemia. Trial Two: Adult male Sprague Dawley rats were administered 1 μg/rat ghrelin, 20 μg/rat ghrelin, or vehicle every morning for 30 days. The terminal blood sample was analyzed for glucose and cholesterol concentrations. The carcasses were analyzed for total lipid and nitrogen content. Carcass total nitrogen concentrations were similar for the control and ghrelin groups. Carcass percent lipid was higher in the 1 μg/rat ghrelin group (P = 0.04). Feed intake among all three groups was the same. Blood glucose concentration, however, tended to be higher in the ghrelin groups than in the control. Blood cholesterol concentration was lower in the ghrelin treated animals. In the second trial, ghrelin injection of 1 μg/rat did cause an increase in adiposity whereas 20 μg/rat did not cause an increase in adiposity. Both ghrelin treatments tended to cause hyperglycemia in rats. In summary, ghrelin increased blood glucose concentration without changing body composition.
Iowa State University
Bohan, Michelle M.; Knight, Travis J.; Wertz, Aimee; Trenkle, Allen H.; and Beitz, Donald C., "Effect of Ghrelin Injection on Blood and Body Composition in Rats" (2003). Beef Research Report, 2003. 21.