INHIBITION OF NMDA-INDUCED INCREASE IN BRAIN TEMPERATURE BY N-OMEGA-NITRO-L-ARGININE AND INDOMETHACIN IN RATS

Intracerebroventricular administration of N-methyl-D-aspartate (NMDA) caused an increase in brain temperature, which appeared rapidly and pr eceded that in rectal temperature, in urethane-anesthetized rats. The increase in brain temperature was divided into two phases, an early in crease and a late increase. Intracerebroventricular indomethacin, a cy clooxygenase inhibitor, completely abolished the NMDA-induced late inc rease, but not the early increase, in brain temperature. On the other hand, intracerebroventricular N-omega-nitro-L-arginine, a potent inhib itor of nitric oxide synthase, strongly suppressed both the early and the late increases. These findings suggest that both nitric oxide and prostaglandins may be involved in the increase in brain temperature af ter NMDA receptor activation.