The presentation and organization of adaptive cytoprotection in the rat stomach,duodenum, and colon.

Background: Adaptive cytoprotection could be demonstrated in lesion attenuation within the whole gastrointestinal tract, in particular sequences, with onset and duration longer than the initial short-lasting period (i.e. one hour) defined by Robert in the stomach only. Material/Methods: Adaptive cytoprotection possibly appeared and lesions were attenuated when the stomach, duodenum or colon, in various combinations and sequences, were challenged with initial (mild) and/or final (strong) irritants over a two-week period. Rats were challenged with the mild or strong irritants 25% or 96% ethanol intragastrically 1 ml/rat (stomach) and cysteamine 40 mg or 400 mg/kg subcutaneously (duodenum), or intrarectally (colon). To postulate the prostaglandin relationship known in Robert's cytoprotection and adaptive cytoprotection, indomethacin (1 mg/kg subcutaneously) was given simultaneously with the second challenge. Results: Administering the mild and strong irritant protocols within the same part of the gastrointestinal tract, adaptive cytoprotection presents in the stomach (1 h to 14 days), duodenum (2 h to 14 days), but not in the colon. With these protocols applied to different parts of the gastrointestinal tract, adaptive cytoprotection cross-reaction was evident in the stomach-duodenum, duodenum-stomach (1 h-14 days and 2 h-14 days), stomach-colon, and duodenum-colon (both 2-24 hours), but not in the colon-stomach or colon-duodenum. This protection was fully antagonized with indomethacin. Conclusions: As observed for a day and even weeks, stomach-duodenum-colon adaptive cytoprotection is an important new defensive phenomenon.