Effects of 5-fluorouracil and zinc on healing of colonic anastomoses in rabbits.

Abstract

To find out if 5-fluorouracil (5-FU) given intraperitoneally to rabbits impaired the healing of colonic anastomoses, and whether giving zinc might reverse the effect. Laboratory study. Teaching hospital, Turkey. 32 New Zealand white rabbits. All animals had 1cm of large bowel resected 10cm proximal to the peritoneal reflection and continuity restored by end-to-end anastomosis. They were divided into four groups and given intraperitoneal injections of saline (control group), 5-FU 10mg/kg/day in a concentration of 5mg/ml saline (5-FU alone group), zinc 2mg/kg/day (zinc alone group), and the same doses of 5-FU and zinc (5-FU + zinc group). The injections were given immediately after operation and daily for 4 days. The rabbits were killed at 7 days. Bursting pressures, tissue hydroxyproline concentrations, tissue zinc concentrations, and light and electron microscopic appearances. Six rabbits died of the complications of anaesthesia and 4 of sepsis leaving 7, 6, 7, and 6 rats in the four groups respectively. Mean (SD) anastomotic bursting pressures were significantly reduced in the 5-FU group compared with controls (5 (2) compared with 7 (1) mm Hg, p: 0.05) and collagen synthesis (indicated by reduced tissue hydroxyproline concentrations) was also decreased (7.1 (0.9) compared with 9.1 (1.5), p < 0.05). Rabbits given 5-FU + zinc had significantly higher bursting pressures than those given 5-FU alone (9 (2) compared with 5 (2), p: 0.01). Bursting pressures were also significantly higher in those given zinc alone, but hydroxyproline concentrations were similar to those in the control group. Histological examination showed that 5-FU alone significantly impaired the healing process, and those in the 5-FU + zinc group healed better than those in the 5-FU alone group. 5-FU given intraperitoneally significantly impaired the healing of colonic anastomoses in rabbits, and zinc reversed this effect.