Cyclooxygenase inhibitors attenuate augmented glutamate release in organum vasculosum laminae terminalis and fever induced by staphylococcal enterotoxin A

Both the hyperthermia and augmented glutamate release in the organum vasculosum laminae terminalis (OVLT) after an intravenous dose (30 ng/kg) of staphylococcal enterotoxin A (SEA) were significantly reduced by pretreatment with intravenous administration of cyclooxygenase inhibitors such as aspirin (1-10 mg/kg), sodium salicylate (1-10 mg/kg), or diclofenac (10 mg/kg). Intra-OVLT administration of 50-200 mug in 1.0 mul of either aspirin or sodium salicylate 60 min before or 120 min after an intra-OVLT dose (50 mug in 1.0 mul) of glutamate also significantly suppressed the glutamate-induced hyperthermia. These findings suggest that inhibition of cyclooxygenase receptor mechanisms suppresses SEA fever by inhibition of glutamate release in the OVLT of rabbit brain.