Journal
AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY
Volume 293, Issue 6, Pages G1281-G1287Publisher
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajpgi.00357.2007
Keywords
trinitrobenzene sulfonic acid; dextran sulfate sodium; inducible nitric oxide synthase; neuronal nitric oxide synthase
Categories
Ask authors/readers for more resources
The role of NO in inflammatory bowel disease is controversial. Studies indicate that endothelial nitric oxide synthase (eNOS) might be involved in protecting the mucosa against colonic inflammation. The aim of this study was to investigate the involvement of nitric oxide (NO) in regulating colonic mucosal blood flow in two different colitis models in rats. In anesthetized control and colitic rats, the distal colon was exteriorized and the mucosa visualized. Blood flow (laser-Doppler flowmetry) and arterial blood pressure were continuously monitored throughout the experiments, and vascular resistance was calculated. Trinitrobenzene sulfonic acid (TNBS) or dextran sulfate sodium (DSS) was used to induce colitis. All groups were given the NOS inhibitor N-omega-nitro-Larginine (L-NNA) or the inducible NOS (iNOS) inhibitor L-N-6-(1-iminoethyl)- lysine (L-NIL). iNOS, eNOS, and neuronal NOS (nNOS) mRNA in colonic samples were investigated with real-time RT-PCR. Before NOS inhibition, colonic mucosal blood flow, expressed as perfusion units, was higher in both colitis models compared with the controls. The blood flow was reduced in the TNBS- and DSS-treated rats during L-NNA administration but was not altered in the control group. Vascular resistance increased more in the TNBS- and DSS-treated rats than in the control rats, indicating a higher level of vasodilating NO in the colitis models. L-NIL did not alter blood pressure or blood flow in any of the groups. iNOS and eNOS mRNA increased in both colitis models, whereas nNOS remained at the control level. TNBS- and DSS-induced colitis results in increased colonic mucosal blood flow, most probably due to increased eNOS activity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available