Abstract
The influence of the sympathetic nervous system activity on oxygen free radicals in tooth extraction wounds was studied in dogs. Cervical sympathetic trunks were stimulated continuously in seven healthy dogs by a portable pacemaker (group S). Postcervical ganglions were permanently blocked with pure ethanol in other seven dogs (group B). Bilateral gingival blood flow was measured in both groups by the hydrogen clearance method and the laser doppler method. Bilateral mandibular premolars and molars were extracted in all dogs of both groups. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and concentration of lipid peroxide (LPO) in gingivas and tooth extraction sockets of all dogs were measured on the fourth day after extraction. The results were as follows : 1. Gingival perfusion significantly decreased in group S and increased in group B in ipsilateral side compared with contralateral side without any remarkable cardiodynamic changes. 2. In group S, the average levels of SOD, GSH-Px activities and LPO concentration in ipsilateral gingivas seemed to be higher than those in contralateral gingivas. The level of CAT activity in ipsilateral gingivas seemed to be the same as that in contralateral gingivas. 3. The levels of SOD and CAT activities in ipsilateral extraction sockets seemed to be lower and the level of GSH-Px activity was significantly lower than those in contralateral extraction sockets in group S. Ipsilateral LPO concentration, however, seemed higher. 4. In group B, the level of ipsilateral gingival SOD activity seemed to be lower, moreover the levels of CAT, GSH-Px activities and LPO concentration were remarkably lower than those in contralateral gingivas. 5. The levels of SOD, CAT, GSH-Px activities and LPO concentration in ipsilateral extraction sockets showed no changes, the same as in contralateral side in group B. These results suggest that ischemia occurring by hyperactivity of sympathetic nervous system accelerates the production of oxygen free radicals in tooth extraction wounds. It seems that increase of perfusion by sympathetic nerve blocks suppresses those accelerations.
