Objective: To study the effect of systemic and local irradiation on wound macrophages (M phi) and the pair promoting action of phenytoin sodium on irradiation-impaired wound healing.
Methods: Wound M phi was collected by polyvinyl alcohol sponges which were implanted in a rat dorsum incision. The number of M phi, phagocytic function of wound M phi, and the release of tumor necrosis factor (TNT alpha) and interleukin-1 (IL-1) from wound M phi, and wound breaking strength (WBS) were respectively investigated.
Results: WBS was deceased after 6Gy systemic irradiation and 20Gy local irradiation, and phenytoin sodium improved WBS in normal wound and radiation-impaired wound. After 6Gy systemic irradiation the phagocytic function of wound M phi, the release of TNF alpha and IL-1 from wound M phi, as well as the number of M phi in wound, were significantly decreased on days 3, 5, 8 after wounding. After 20Gy local irradiation, the ratio of M phi in wound cells was significantly decreased on days 3, 5, 8, 13 after wounding, but the function of macrophage was not significantly decreased. Phenytoin sodium significantly increased the number of wound M phi, improved the phagocytic function of M phi, and the release of TNF alpha and IL-I from wound M phi on days 3, 5, 8 days after wounding despite the rats were radiated or not.
Conclusion: The results indicated that the decrease of number and function of wound M phi play an important role in the impairment of early wound healing by systemic irradiation. Phenytoin sodium accelerated normal and irradiation-impaired wound healing by increasing the number of wound M phi and improving the M phi function.