[Immunochemical identification and localization of cytochrome P-45OHS; isozyme in human gastric mucosa and gastric carcinoma].
Monoclonal antibody to rat liver cytochrome P-450 j isozyme, an activating enzyme specific to nitrosamine metabolism, was used in combination with immunoblotting, densitometer scanning of SDS-PAGE gels, and immunohistochemical staining, there was a trace of P-450 isozyme (Mr. 51. 5 kd) in human gastric mucosa with or without cancer. It was similar to P-450 j in molecular weight, catalysis and immunochemistry. We named it P-450 HSj isozyme. Both in 25 gastric cancer patients and 17 non-cancer patients, the concentrations (%) of P-450 HSj in the mucosa of the lesser curvature were higher than those of the greater curvature (P less than 0.01). This might be one of the important reasons why gastric carcinoma caused by nitrosamines is most common in the lesser curvature. The P-450 HSj was localized in the cytoplasm of some epithelial cells, especially in the glands with hyperplastic and intestinal metaplastic changes adjacent to carcinoma. It was also found in some normal glands and in tumor cells of highly differentiated adenocarcinoma, but not in tumor cells of lowly differentiated adenocarcinoma.
Fang
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D000230:Adenocarcinoma / Q000201:enzymology; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D005753:Gastric Mucosa / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes / Q000032:analysis*; D013274:Stomach Neoplasms / Q000201:enzymology*
D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System