简介：Monoclonalantibody(MAb)toratlivercyto-chromeP-450jisozyme,anactivatingenzymespecifictonitrosaminemetabolism,wasusedcoupledwithimmunoblotting,densitometerscanningofSDS-PAGEgelsandimmunohistochemicaltechnique.ThetraceP-450HSjisozyme(Mr.51.5Kd)wasfoundinhumangastricmucosa.ItwassimilartoP-450jinmolecularweight,catalyticandimmunochemicalproperties.TheconcentrationsofP-450HSjinmucosaoflessercurvaturewerehigherthanthoseingreatercurvature.Thismightbeoneoftheimportantreasonsthatlessercurvatureisthecommonestareaforgastriccarcinoma.ButtherewaspossiblylessP-450HSjingastricmucosawithcancer.Im-munohistochemically,P-450HSjwasdiscoveredinthecytoplasmofsomeglandularepithelialcells,especiallyintheglandswithhyperplasticandintestinalmetaplasticchangesadjacenttocarcinoma.Itwasalsofoundinsomenormalglandsandintumorcellsofhigh-differentiatedadenocarcinoma,butnotinthoseoflow-differentia