PLASMA NITRATE CONCENTRATIONS IN NEUTROPENIC AND NON-NEUTROPENIC PATIENTS WITH SUSPECTED SEPTICEMIA

Nitric oxide (NO) is an important physiological mediator of vascular t one and is thought to be involved in the pathogenesis of septic shock. Plasma nitrate is the stable end product of NO oxidation and in part reflects endogenous NO production. We measured plasma nitrate levels i n 47 episodes of suspected septicaemia in 43 in-patients(l6 male and 2 7 female, age 15-63 years). Nitrate concentrations were significantly higher (P < 0.01) compared to healthy controls. Further analysis revea led that significantly elevated levels occurred only in the septic pat ients who had normal or elevated numbers of neutrophils in the periphe ral blood and were hypotensive on presentation. Failure of plasma nitr ate concentrations to rise significantly in patients with neutropenia suggests that this cell type may be important in the activation of the arginine-NO system in severe sepsis in man.