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.