RESUMO
Background:Cu-Zn superoxide dismutases are antioxidative defensive enzymes that catalyze the reduction of superoxide anions to hydrogen peroxide. Aim:The study focuses on the association of electromorph of superoxide dismutase with duodenal ulcers, which result due to an imbalance between aggressive and defensive factors. Materials and Methods:Endoscopically confirmed 210 duodenal ulcer patients and 185 healthy individuals for comparative analysis were considered for the present study. Phenotyping of superoxide dismutase was carried out by subjecting the RBC membranes to polyacrylamide gel electrophoresis, using appropriate staining protocols. Results:Statistical analysis of SOD phenotypes revealed a significant increase of SOD A*2 allele and Superoxide dismutases (SOD) 2-2 phenotype in duodenal ulcer group. Among these individuals, a predominance of Helicobacter pylori infection was observed. The increased preponderance of homozygotes can be explained on the basis of reduced and altered enzyme activity, which may lead to disturbance in homeostasis of antioxidant/oxidant culminating in high lipid peroxidative gastric mucosal tissue damage and ulceration. No variation in the distribution of SOD phenotypes with respect to Helicobacter pylori indicates the role of Mn-SOD rather than Cu-Zn SOD in the Helicobacter pylori infected cases as reported earlier. Conclusions:Superoxide dismutase as a genetic marker / gene modifier, encoding for an antioxidant enzyme in maintaining tissue homeostasis of the gastric mucosa is discussed.
RESUMO
BACKGROUND: Duodenal ulcers are mucosal erosions that penetrate into the muscularis propria of the duodenum. They are a result of an imbalance between aggressive and defensive factors. Various environmental factors like Helicobacter pylori infection, addictions to smoking and alcohol etc. and genetic factors have been reported to be associated with duodenal ulceration. Alpha-1-antitrypsin was studied for its role as a genetic marker and specific allelic association to protein functioning and alteration. Serum samples from 185 normal subjects and 210 duodenal ulcer cases were typed for the phenotypes following PAGE (polyacrylamide gel electrophoresis) and immunofixation using specific commercial antisera with appropriate staining protocols. In general, 'M' allele of alpha-1-antitrypsin was found to be predominant in healthy normal subjects, with the gene frequencies being 0.679 (M), 0.299 (Z) and 0.0214 (S). Whereas in duodenal ulcer cases, Z and S alleles were found to be predominant with a significant association of MS, ZZ and MZ phenotypes (c2sub : 49.98) and the gene frequencies being 0. 113 (M), 0. 347 (Z) and 0.506 (S). Predominance of Z and S alleles indicates that these alleles may encode for reduced synthesis of alpha-1-antitrypsin, hence decreased neutralization of proteases like trypsin and chymotrypsin inhibited by alpha-1-antitrypsin, thereby resulting in ulcers. The study highlights the association of Z and S alleles of the potent protease inhibitor alpha-1-antitrypsin and also suggests its role as a genetic marker in ulcerogenesis.