EFFECTS OF VESICOCOLIC ANASTOMOSIS ON THE PROLIFERATION OF COLONIC MUCOSA IN A RAT MODEL

The effects of diverting the urinary stream into a defunctioned segment of the distal colon has been studied in a rat model. Distal rat colon was defunctioned using the Hartmann's procedure and a vesicocolic anastomosis was performed 14 days later. The distal colon was harvested after 10 days following the administration of a vinblastine mitotic block either 1 or 3 h before death. Both the mean crypt cell proliferation and the crypt length were increased significantly in the colonic mucosa exposed to urine when compared with the control defunctioned colon or to the functional unexposed proximal colon. An active fraction was obtained from human urine by elution from a diethylaminoethyl sepharose column using 1 mol/L NaCl. This fraction was administered intraluminally to defunctioned rat colons using Alzet miniosmotic pumps. In these animals the crypt cell production rate was significantly increased compared with the control animals. Although the crypt length did not increase significantly in these animals the atrophy normally seen in defunctioned colonic mucosa did not occur. The identity of the active molecule in this urine fraction is still being determined.