INFLUENCE OF COLOSTOMY ON IN-VIVO AND IN-VITRO PERMEABILITY OF THE RAT COLON

PURPOSE: Barrier properties of an isolated colon loop and the remnant colon in continuity with the gastrointestinal tract after colostomy we re studied in the rat. METHODS: The in vivo absorption after colonic l oop administration of the marker fluorescein sodium was measured as th e urinary recovery. The in vitro permeability was measured in Ussing d iffusion chambers as the transmucosal passage of [C-14]mannitol and of human serum albumin in the isolated and the nonexcluded colonic segme nts and was compared with the corresponding colonic regions from sham- operated rats atl to 14 days after operation. RESULTS: Body weight gai n of the rats decreased and diarrhea appeared from day 2 after colosto my. Histologic examination showed mucosal atrophy with decreased villu s height in the isolated colonic loop and an increased villus height i n the nonexcluded colon segment. Absorption of fluorescein sodium in t he isolated loop was increased at 8 and 14 days. Moreover, permeabilit y in the isolated loop was increased for both mannitol and human serum albumin from four days after colostomy compared with the correspondin g colonic segments after the sham operation, whereas a decrease in the passage of mannitol was noted in the nonexcluded colon. CONCLUSIONS: Experimentally performed colostomy diver ion in the rat induced altera tions of the barrier function in both the isolated colonic loop and th e nonexcluded colon in continuity with the fecal stream.