Confirmation of nitric oxide synthesis in active ulcerative colitis by infra-red diode laser spectroscopy.

The synthesis of nitric oxide (NO) in the colonic mucosa of patients affected by ulcerative colitis (UC) has been previously investigated using indirect measurements of enzyme activity and non-specific measurements of luminal NO gas. The aim of this study was to determine unequivocally if luminal NO gas in active UC is present in greater concentrations than in healthy control subjects. Luminal gas was collected from eight patients with active UC and eight healthy volunteers. NO gas concentration was measured using diode laser spectroscopy. NO gas was detected in four of eight patients with active UC (range 0.13-1.1 nmol) and none of the healthy control subjects. NO gas is present in greater concentrations in patients with active UC than in control subjects. This supports the view that mucosal NO synthesis is increased in ulcerative colitis.