Changes in dental blood flow following electrical tooth pulp stimulation--influences of capsaicin and guanethidine.

The responses of rat incisors microcirculation to electrical pulp stimulation was examined. A fast initial decrease was followed by a long lasting increase in blood flow due to activation of sympathetic efferents and nociceptive afferents, respectively. Both constituents of the response could be abolished differentially by the use of guanethidine (sympathectomy) and capsaicin (C-deafferentiation), respectively. The results point to a role of both C-efferents and peptidergic C-afferents in the control of tooth pulp circulation.