The anti-inflammatory effects of quinolinic acid in the rat

Quinolinic acid (QUIN) levels are elevated in patients and animals sufferin g from chronic infectious diseases. In the present study, male Sprague-Dawl ey rats were used to test the anti-inflammatory effects of QUIN using the c arrageenan (CGN)-induced paw edema assay and the CGN sponge assay. Results of these studies indicate that QUIN (30, 100 or 300 mg/kg i.p.) caused a re duction of carrageenan-induced inflammation by as much as 80% at the highes t dose. Moreover, QUIN reduced exudate volume and inhibited leukocyte migra tion in the sponge granuloma assay. In another experiment, the anti-inflamm atory activity of QUIN was eliminated in adrenalectomized rats. QUIN did no t reduce edema caused by arachidonic acid, bradykinin or compound 48/80. Ne ither morphine nor naloxone altered the anti-inflammatory activity of QUIN. These results may suggest that QUIN exerts its anti-inflammatory activity through a direct action on neutrophils or vascular permeability.