Activity of inducible and neuronal nitric oxide synthases in colonic mucosa predicts progression of ulcerative colitis.
OBJECTIVE
The present study analyzes inducible and neuronal nitric oxide synthase activity and expression in colonic mucosa of patients with ulcerative colitis, and correlates them with the progression of disease extent.


METHODS
Thirty patients with ulcerative colitis were included. Synthases activity and expression were analyzed both in inflamed and noninflamed mucosa. After 2 yr, disease extent was determined and compared with extent at inclusion.


RESULTS
Ca(2+)-independent activity, expressed as median with (interquartile range), in inflamed mucosa was higher than in noninflamed and control mucosa (102 (165-66), 24 (50-3), 1 (2.5-0.1) pmol.min(-1) mg prot(-1), respectively, p < 0.005), whereas Ca(2+)-dependent activity was significantly lower in inflamed than in noninflamed and control mucosa. Western blot analysis identified inducible and neuronal isoforms and confirmed these differences. Patients with more extended disease after 2 yr had higher levels of Ca(2+)-independent activity in noninflamed mucosa at inclusion and lower levels of Ca(2+)-dependent activity than patients with persistence of similar extent of inflammation (50 (78-29) vs 8 (30-0.1), p < 0.005; 51 (100-36) vs 150 (156-106), p < 0.05, respectively). Values of Ca(2+)-independent activity in noninflamed mucosa greater than 30 pmol. min(-1) mg prot(-1) showed 80% sensitivity and 87.5% specificity in the detection of patients with subsequent progression of disease extent, whereas values of Ca(2+)-dependent activity in noninflamed mucosa greater than 125 pmol. min(-1) mg prot(-1) showed 75% sensitivity and 80% specificity in the detection of patients with stability of disease extent. A ratio of Ca(2+)-independent/Ca(2+)-dependent activities over 0.29 showed 90% sensitivity and 87.5% specificity in the detection of patients with subsequent progression of extent.


CONCLUSIONS
Our results show an up-regulation of inducible nitric oxide synthase and a down-regulation of neuronal isoform not only in inflamed mucosa but also in apparently healthy mucosa of patients with ulcerative colitis. The values of activity of both isoforms in apparently healthy mucosa could predict the disease extent after 2 yr follow-up.
Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid, Spain.
Luis
L
Menchén
Arturo L
AL
Colón
José L M
JL
Madrigal
Luis
L
Beltrán
Sofía
S
Botella
Ignacio
I
Lizasoain
Juan C
JC
Leza
María A
MA
Moro
Pedro
P
Menchén
Enrique
E
Cos
Pedro
P
Lorenzo
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D015153:Blotting, Western; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000201:enzymology* / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000201:enzymology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D011336:Probability; D011379:Prognosis; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
D015415:Biomarkers; C496320:NOS1 protein, human; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II