Cellular changes in denervated tissue during wound healing in a rat model

There is increasing evidence that innervation, possibly mediated via neurop eptides, promotes wound healing. This study presents data on the early cell ular events during healing in denervated tissue. Free oblique groin flaps w ere raised on 25 adult Sprague-Dawley rats. Excisional wounds were placed w ithin the flap and in two control sites, the contralateral inguinal region and the thorax. The absence of innervation in the free flap wounds was conf irmed 10 days after surgery by indirect immunofluorescence with a pan-neuro nal marker. The cellular infiltrate of the wounds was analysed immunohistoc hemically with a panel of antibodies to rat macrophages and monocytes (ED1) , rat B lymphocytes (CD45R) and T lymphocytes (CD2). The immunostained cell ular infiltrate was quantified at 2, 4, 7 and 10 days postoperatively. Our results show that denervated wounds have a significantly lower macrophage a nd T-lymphocyte count at day 4 of wound healing (P < 0.05). Inflammatory ce lls, particularly macrophages, are known to play an important part in wound healing and their reduced chemotaxis in denervated tissue may be related t o the observed delay in wound closure.