MUCOSAL BLOOD-FLOW AND GENERATION OF SUPEROXIDE IN RAT EXPERIMENTAL COLITIS INDUCED BY SUCCINIC ACID

As we consider succinic acid to be an exacerbating factor in ulcerativ e colitis, we investigated its influence on rat colonic mucosa in term s of mucosal blood flow and superoxide generation. We measured mucosal blood flow by the hydrogen gas clearance method and superoxide genera tion by the chemiluminescence method, and observed histopathological f indings to determine the effects of succinic acid, After the instillat ion of succinic acid of any concentration tested to the colon, mucosal blood flow decreased. Histopathologically, the higher the concentrati on of succinic acid, the greater was the erosion formation in the colo nic mucosa, while significant polymorphonuclear cell infiltration and superoxide generation from colon tissue were observed with 0.01% succi nic acid compared with higher or lower concentrations. Succinic acid, at fecal concentrations found in active stage ulcerative colitis, appe ars to be implicated in mucosal injury, mediated by a decrease in colo nic mucosal blood flow and infiltration of superoxide-generating polym orphonuclear cells into the mucosa.