Radiation-induced acute intestinal inflammation differs following total-body versus abdominopelvic irradiation in the ferret

Abstract

Purpose : The studies were designed to investigate the differences in the intestinal inflammatory response following abdominopelvic or total-body irradiation in a ferret model. Materials and methods : Ferrets were exposed either to total-body or to abdominopelvic γ-radiation (5 Gy) and various parameters of inflammation studied in the jejunum, ileum and colon 2 and 7 days later. Results : Abdominopelvic and, to a greater extent, total-body irradiation caused weight loss by 7 days. White blood cell counts were reduced in both groups, but more so following total-body irradiation. Myeloperoxidase activity was significantly increased in the ileum 2 days after abdominopelvic irradiation, but it was reduced after total-body irradiation. Total-body irradiation increased tissue prostaglandin E 2 levels in all regions at 2 days and decreased jejunal leukotriene B 4 levels in the jejunum at both time points. Ileal prostaglandin E 2 levels were increased 2 days after abdominopelvic irradiation. Expression of inducible nitric oxide synthase was not altered by either irradiation protocol. Conclusions : The data show that there are regional differences in the intestinal response to irradiation, depending on whether it was delivered to the whole body or locally to the abdominopelvic region. In particular, the ileum exhibited an acute increase in myeloperoxidase activity following abdominopelvic but not total-body irradiation.