E. Klinowski et al., SUPEROXIDE-DISMUTASE ACTIVITY IN DUODENAL-ULCER PATIENTS, European journal of gastroenterology & hepatology, 8(12), 1996, pp. 1151-1155
Objective: To investigate whether duodenal ulcer (DU) is associated wi
th increased free radical generation at the site of ulceration and to
attempt, indirectly, to confirm the hypothesis by determining activity
of free radical scavengers such as superoxide dismutase (SOD). Study
design: Prospective study comparing SOD activity in biopsies taken fro
m the ulcer edge, and antrum in DU patients before and after one month
of treatment to SOD activity in biopsies from the duodenal bulb and a
ntrum in a control population. Setting: Institute of Gastroenterology
of a university hospital. Study population: Twenty-five patients with
DU. The diagnosis was confirmed by endoscopy. Measurements: SOD activi
ty in biopsy specimen, red blood cells (RBC) and serum was measured us
ing the cytochrome c method by spectrophotometry and expressed as U SO
D/mg protein. Helicobacter pylori was diagnosed by the rapid urease le
st (CLO test) from antral biopsies. Results: SOD activity was markedly
depleted in the ulcer edge (2.78 +/- 0.9 U SOD/mg protein) as compare
d to the same patients after one month of treatment (4.59 +/- 2.2 U SO
D/mg protein) (P = 0.05) and to biopsies from the duodenal bulb in con
trol population (6.7 +/- 2.4 U. SOD/mg protein) (P = 0.05). SOD activi
ty in the antrum of both groups was similar. There was no difference i
n SOD activity in RBC and serum of both groups. Conclusion: Products o
f free radical reactions are implicated in the pathogenesis of DU dise
ase. SOD, which is a key enzyme in gastric mucosal protection, is depl
eted significantly in the ulcer edge compared with controls and increa
ses after healing. However, it is not clear whether this abnormality i
n oxygen free radical metabolism reflects, rather than causes, the con
dition which characterizes DU.