Denisenko N. The state of L-arginine/NO-synthase system and lipid peroxidation processes after modulation of cyclooxygenase activity and serotonin concentration in colon mucosa of rats under conditions of stress and colitis.

The purpose of this work was to find out the changes in the functioning of the NO-synthase/arginase system, pro- and antioxidant processes after the inhibition of cyclooxigenase, and the modulation of serotonin and hydrogen sulfide content in rat’s colon mucosa under the conditions of stress and colitis. The studies were conducted on white outbred rats (n=300) of both sexes. Nonselective inhibition of cyclooxigenase under conditions of stress caused increase of superoxide dismutase activity (p<0,05) compared with the action of the stress, and under conditions of colitis (p<0,05) compared with the action of colitis, reflecting growth of superoxide radicals production and lipid peroxidation activation. Hydrogen sulfide-releasing cyclooxigenase inhibitor, administered under the conditions of stress resulted in decreased thiobarbituric acid (TBA)-active products concentration (p<0,05) and increased number of goblet cells in crypt (p<0,01) in colon mucosa. The effect of the hydrogen sulfide-releasing cyclooxigenase inhibitor on the background of the colitis demonstrated the inhibition of NO production by inducible NO-synthase (p<0,001) compared to colitis.