Effect of epidermal growth factor (EGF) on experimental granulation tissue

Subcutaneously implanted cylindrical hollow viscose cellulose sponges were used to study the effects of locally applied epidermal growth factor (EGF) on developing granulation tissue in rats. In the first set of experiments the test implants were treated with a single injection of a solution containing 5 micrograms of EGF in 0.5% albumin while the control implants were treated correspondingly with the carrier solution only. In the second set of experiments the injections of both test and control implants were repeated daily. Analyses of wound fluid and granulation tissue in the sponge cylinders were carried out 10 days after implantation. After single application of EGF no essential differences were detected in wound fluid prostaglandin E2 levels or various components of granulation tissue between the groups. After daily application, however, a stimulatory effect of EGF on granulation tissue formation was observed: cellularity increased, as evidenced by the elevated amounts of nucleic acids, and accumulation of collagen and glycosaminoglycans was enhanced.