MISOPROSTOL IN THE INTESTINAL LUMEN PROTECTS AGAINST RADIATION-INJURYOF THE MUCOSA OF THE SMALL-BOWEL

Systemically administered misoprostol, a PGE(1) analog, has been shown to be an intestinal radioprotector. The purpose of this study was to determine if administration of misoprostol into the intestinal lumen c an also reduce the severity of acute radiation enteritis. The rat smal l bowel was operatively exteriorized and segmented by means of suture ties. The remainder of the intestine and the rat were shielded in a le ad box. Misoprostol was introduced into the lumen in various doses. Af ter 30 min exposure to misoprostol, the isolated, exteriorized, segmen ted bowel was subjected to 11 Gy X irradiation. Five days later the an imals were sacrificed and the intestines harvested for evaluation. Sur viving crypt numbers per circumference and mucosal height were the cri teria used for quantification of damage. Mucosa exposed to misoprostol at the time of radiation delivery showed significantly increased cryp t numbers and mucosal height compared to adjacent saline-filled intest ine.