The metabolisms of reactive nitrogen and
oxygen intermediates (RNI and ROI) in patients with cutaneous
leishmaniasis (CL) were investigated and compared with those of
healthy subjects. To determine RNI metabolism, nitrite plus nitrate
concentrations were measured spectrophotometrically. Nitrite
concentration in plasma was determined directly by the Griess
method. Nitrate levels in plasma were measured after reduction into
nitrite by using copper-cadmium-zinc. ROI metabolism was evaluated
by measuring erythrocyte superoxide dismutase, catalase and
glutathione peroxidase activities. Plasma nitrite plus nitrate
levels and erythrocyte superoxide dismutase activity were higher in
the patient group than healthy subjects (p<0.01). In contrast,
erythrocyte catalase and glutathione peroxidase activities were
lower (p<0.05, p<0.01, respectively). ROI metabolism was
altered in relation to hydrogen peroxide elevation in patients with
CL. These alterations in ROI enable nitric oxide (NO) to amplify
its leishmanicidal effect. The determination of ROI and RNI in
patients with CL may be a useful tool to evaluate effector
mechanisms of NO and clinical manifestations.