Nitric Oxide is an Indicator of Peritonitis in Patients on Continuous Ambulatory Peritoneal Dialysis Nitric oxide (NO) plays an important role in mediating the inflammatory process. The aim of this study was to evaluate the increament of nitric oxide production during peritoniti ; in patients receiving continuous ambulatory peritoneal dialysis (CAPD). Nitrat, a stable metabolite of NO, was measured plasma and dialysate. The study population comprised 12 patients with 18 episodes of peritonitis. Seven patients without peritonitis were controls. NO was measured by colorimetric Green LC method The median dialysate/plasma (D/P) ratio nitrate in acute phase peritonitis was 1.38, which was higher than after recovery (1.24, p