The effect of 5-fluorouracil on abdominal wound healing in rats

We carried out experiments to test the hypothesis that 5-Fluorouracil would retard wound healing when administration was started on the day of operation. Abdominal wounds were made in rats and closed again, and some of the animals were given daily 5-FU, the rest acting as controls. Test animals were killed three, five, seven and 10 days after operation, and the strength of their wounds was measured. At five and seven days the control wounds were 10 times stronger than those of the treated animals, and at 10 days they were four times stronger. We speculated that the difference in strength might be largely due to the observed fact that the muscle layer in the treated animals was considerably weaker than in the controls. We concluded that it would be unsafe to start giving 5-FU to patients immediately after operation.