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

The effects of diverting the urinary stream into a defunctioned segmen t of the distal colon has been studied in a rat model. Distal rat colo n was defunctioned using the Hartmann's procedure and a vesicocolic an astomosis was performed 14 days later. The distal colon was harvested after 10 days following the administration of a vinblastine mitotic bl ock either 1 or 3 h before death. Both the mean crypt cell proliferati on and the crypt length were increased significantly in the colonic mu cosa exposed to urine when compared with the control defunctioned colo n or to the functional unexposed proximal colon. An active fraction wa s obtained from human urine by elution from a diethylaminoethyl sephar ose column using 1 mol/L NaCl. This fraction was administered intralum inally to defunctioned rat colons using Alzet miniosmotic pumps. In th ese 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 d efunctioned colonic mucosa did not occur. The identity of the active m olecule in this urine fraction is still being determined.