REACTION OF MICROGLIAL CELLS AND MACROPHAGES AFTER CORTICAL INCISION IN RATS - EFFECT OF A SYNTHESIZED FREE-RADICAL SCAVENGER,(+ -)-N,N'-PROPYLENEDINICOTINAMIDE (AVS)/

Reactive microglial cells and macrophages appear after trauma to the b rain. To investigate the accumulation patterns of reactive microgial c ells and macrophages after cortical incision, these cells were stained immunohistochemically with anti-EDl antibody in the brain sections be fore and 1, 3, 5, and 7 days after incision. And to ascertain the part icipation of oxygen free radicals in these cellular reactions, a synth esized free radical scavenger, (+/-)-N,N'-propylenedinicotinamide (AVS ) was administered in this model. Rats were administered AVS (300 mg/k g, i.p.) 30 min before, 2.5 h and every 24 h after incision (AVS group ), while only saline was administered in the same manner as a control (saline group). In the saline group, both reactive microglial cells an d macrophages had already appeared on day 1 post-incision. The former continued to increase in number during the following days, whereas the latter increased in number up to day 3 and thereafter decreased. Both the numbers of reactive microglial cells and macrophages were signifi cantly decreased (P < 0.05) in the AVS group on days 5 and 7. The resu lts suggest the participation of oxygen free radicals in the reaction of microglial cells and macrophages in traumatic brain injury.