Acute radiation enteritis in rats: bile salts and trypsin.

Surgically exteriorized rat intestine divided into segments containing saline solution, a bile salt binder, or a trypsin inhibitor were radiated (1100 cGy) and subsequently evaluated for histologic damage. Five days after radiation, crypt cell numbers, mucosal height, and mucous cell numbers were significantly greater in segments protected by the binding of bile salts or the absence of trypsin activity compared with saline-bathed mucosa. Thus both proteolytic enzymes and bile salts in the lumen contribute to the acute enteritis that follows a single dose of x-radiation.