INCREASED LUMINAL NITRIC-OXIDE IN INFLAMMATORY BOWEL-DISEASE AS SHOWNWITH A NOVEL MINIMALLY INVASIVE METHOD

Background: The production of nitric oxide (NO) is increased in ulcera tive colitis, as shown by bioassays of NO synthase activity in mucosal biopsy specimens. We wanted to develop a less invasive method for mea surement nf NO directly in the rectum in patients with inflammatory bo wel disease (IBD). Methods: We studied 10 patients with active ulcerat ive colitis, 6 with active Crohn's disease, 6 with non-active ulcerati ve colitis, and 24 controls without inflammation A tonometer balloon c atheter was inserted in the rectum and inflated with 5 ml of NO-free a ir. After 15 min of incubation the sample was extracted, and the NO co ncentration was immediately analysed with a chemiluminescence techniqu e. Results: Patients with active disease had greatly increased concent rations of NO in the rectum as compared with controls and patients wit h non-active disease. Conclusions: During inflammation in the large in testine increased amounts of NO are released from the mucosa. Measurem ents of NO directly in the rectum could be of help in further understa nding the role of this gas in IBD. Moreover. it is tempting to specula te that this minimally invasive method could be clinically useful as a diagnostic tool and in monitoring the effect of therapy.