Changes in the gastric ghrelin concentration after whole-abdominal irradiation in rats: Is this related to the radiation-induced anorexia and weight loss?

Background : Ghrelin is a hormone related to food intake in rodents and humans, mainly produced in stomach. This study aimed to determine the effect of irradiaon on ghrelin concentraon in the gastric mucosa of rats. Materials and Methods : Twenty-five rats were exposed to 15 Gy of whole- abdominal irradiaon. Gastricssue samples were ob tained 1, 3, 7, 30, and 90 days a'er irradiaon. Five non-irradiated rats w ere used as controls. The number of ghrelin cells that reacted with an�-ghrelin anbody was counted. Moreover, ghrelin mRNA expression was determined. Food intake and body weight changes were measured simultaneously. Results : Compared to the controls, irradiated rats showed a significantly decreased gastric ghrelin cell count, i.e., 29%, 30%, 32%, and 32% at 1, 3, 30, and 90 days, respecvely, a'er irradiaon (p < 0.05). Irradiated rats also sh owed decreased ghrelin mRNA expression; the expression decreased by 54.1%, 58.8%, 52.0%, and 52.7% at 1, 3, 30, and 90 days, respecvely (p < 0.05). Food intake of irradiated rats decreased connuously compared with the control rats, except at 90 days. Body weight of the irradiated rats was lower than that of the controls at 7 and 30 days. Conclusion : This study demonstrated that abdominal irradiaon can reduce gastric ghrelin concentraon. Though decrease of food intake and body weight was observed simultaneously, further evaluaon needs to find out the relaonship between gastric ghrelin level and food intake a'er exposure to irradiaon.