EVIDENCE FOR THE INVOLVEMENT OF NITRIC-OXIDE IN THE ANTINOCICEPTIVE EFFECT OF KETOROLAC

The involvement of nitric oxide in the antinociception produced by ket orolac was assessed using the pain-induced functional impairment model in the rat: 800 mu g of N-G-nitro-L-arginine methyl ester, an inhibit or of nitric oxide synthesis, or saline was injected intra-articularly in a hind limb joint previously injured with uric acid. Animals then received ketorolac, dipyrone or no drug. Ketorolac and dipyrone produc ed a significant antinociceptive effect which was reduced by pretreatm ent with N-G-nitro-L-arginine methyl ester, but not with saline. It is concluded that the antinociceptive effect of both drugs involves the local participation of nitric oxide.