[Leukocytic and thrombocytic generation of nitric oxide in patients with bronchial asthma]

Leukocytic and thrombocytic nitric oxide generation was studied in 23 healthy individuals and 17 patients with bronchial asthma. Differential centrifugation was used to isolate leukocytes and platelets from blood. The suspensions of leukocytes (5.10(6)) and platelets (0.5.10(8)) were incubated in 0.5 ml of the medium RPMI 1640 at 37 degrees C for 15 hours. The concentration of the stable metabolite of NO nitrite was estimated by the Griss test. The relative leukocytic NO production was 0.75 +/- 0.06 and 1.32 +/- 0.06 mumole/l in healthy individuals and patients, respectively (p < 0.001). The relative thrombocytic NO production was 2.15 +/- 0.14 and 2.26 +/- 0.07 mumole/l in healthy individuals and patients, respectively. The absolute leukocytic NO production was 0.47 +/- 0.05 and 0.65 +/- 0.05 mumol/l in healthy individuals and patients, respectively (p < 0.01). The absolute thrombocytic NO production was 7.70 +/- 0.55 and 5.32 +/- 0.27 mumole/l in healthy individuals and patients, respectively (p < 0.001). Therefore, the absolute production of NO by platelets is 16 times higher than that by leukocytes. In the patients, the relative and absolute leukocytic NO productions increased and the absolute thrombocytic NO production significantly decreased.