Cyclooxygenase Inhibitors Attenuate Augmented Glutamate Release in Organum Vasculosum Laminae Terminalis and Fever Induced by Staphylococcal Enterotoxin A

Abstract

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 μg in 1.0 μl of either aspirin or sodium salicylate 60 min before or 120 min after an intra-OVLT dose (50 μg in 1.0 μl) 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. Keywords:: glutamate, fever, diclofenac