PLASMA NITRATE CONCENTRATION AND URINARY NITRATE EXCRETION IN PATIENTS WITH GASTROENTERITIS

The concentration of nitrate (the stable oxidation product of nitric o xide) in plasma and its excretion in urine was measured in 20 patients with a diagnosis of gastroenteritis. On day 1 of the illness plasma n itrate concentration was significantly elevated compared with a health y control population (92.7 +/- 17.0 mu mol/l vs. 33.1 +/- 1.6 mu mol/l ; P<0.001) and continued to be elevated on days 2 and 3. Urinary nitra te excretion was also elevated. The plasma nitrate concentration corre lated with disease severity as assessed by stool frequency and plasma urea concentration. Plasma nitrate concentration may be a sensitive an d clinically useful indicator of severity of gastroenteritis.