Contribution of insulin-like growth factor I to the healing of colonic anastomoses in rats.

The aim of this experimental study was to investigate the contribution of insulin-like growth factor I (IGF)-I in the colonic healing process when injected intraperitoneally after colon resection. Forty male Wistar rats were used. Rats in the control group were injected with 3 mL of a solution of 0.9% NaCl intraperitoneally after the operation and on postoperative day 2, 4, and 6. Rats in the IGF-I group received recombinant human IGF-I in a dose of 2 mg/kg body weight intraperitoneally, immediately after the colonic anastomosis was performed and on postoperative day 2, 4, and 6. All rats were killed on postoperative day 7. The hydroxyproline tissue content was significantly higher in the IGF-1 group than in the control group. The bursting pressures were also significantly higher in IGF-1 group than in the control group. The weight change between the groups differed significantly; in the control group the average weight decreased about 5% postoperatively, while in the IGF-1 group the average weight increased about 6%. The average inflammatory cell infiltration score was significantly higher in the control group. Neoagiogenesis did not differ significantly between the two groups. The fibroblast activity differed significantly between the two groups, as the control group had significantly less fibroblasts compared to the IGF-1 group. In conclusion, IGF-I when given intraperitoneally stimulates the healing of colonic anastomoses in the rats. Further studies are required in order to determine whether this effect is dose related.