Tear nitrite and nitrate levels as nitric oxide end products in patients with Behcet's disease and non-Behcet's uveitis

To evaluate the role of nitric oxide (NO) in ocular inflammation, tear nitr ite and nitrates (NN) as NO end products were determined in 11 patients wit h Behcet's disease (BD) and in 11 with non-Behcet's uveitis (NBU) during th e active and remission stages and in 12 healthy controls. Median (with the range) NN levels were 82.29 (59.60-98.25) mu mol/l in the active and 98.25 (52.88-246.92) mu mol/l in the remission stage of ED; 88.17 (25.99-116.73) mu mol/l in the active and 83.00 (31.04-250.28) mu mol/l in the remission s tage of NBU and 109.17 (88.17-158.74) mu mol/l in the controls. The NN leve ls in the active stage of ED and NBU were significantly decreased when comp ared to the controls (p < 0.05; Kruskal-Wallis test). Decreased NN levels a t the activation stage may be caused by the rapid transformation of the NO to peroxynitrites, which are highly oxidizing and cytotoxic substances. Cop yright (C) 2001 S. Karger AG, Basel.