Effect of cyclooxygenase-2 on the regulation of cerebral blood flow during neuronal activation in the rat.

The present study was designed to clarify the precision of the main approach for investigating the regulation of local cerebral blood flow (CBF) response to neuronal activation in the brain (neurovascular coupling). In this study, we examined the effects of NS-398, a highly selective cyclooxygenase-2 inhibitor, on the physiological variables, baseline CBF, and local CBF response during rat somatosensory neuronal activation by laser-Doppler flowmetry. Blood pressure and heart rate were significantly decreased 3h after i.v. infusion of NS-398. Baseline CBF and local CBF during somatosensory activation gradually decreased with an increase in time of NS-398 infusion up to 3h, although neuronal activity in the somatosensory area was almost constant during the infusion. The results suggest that cyclooxygenase-2 participates in the regulation of local CBF during neuronal activation in rats. The present study also revealed the potential side-effects of dimethylsulfoxide, a solvent of NS-398, on neurovascular coupling.