title: [Characteristics of the epidermal growth factor receptors in the epithelium of the gastrointestinal tract of rats and in intestinal tumors induced by 1,2-dimethylhydrazine].
abstract: Using the Scatchard analysis of 125J-EGF binding it was shown that plasma membranes of gastric and small intestinal epithelial cells contain approximately 20 times less EGF-receptors (EGF-R) than liver cells. Investigation of the phosphorylation activity of EGF-R-kinase was performed in vitro on plasma membranes from intestine, intestinal tumours and liver cells. The main protein phosphorylated at tyrosine in the tumours was p34 but the intensity of EGF-R autophosphorylation and its total protein-tyrosine kinase activity were reduced (as compared with small-intestinal and liver cell membranes). In the tumours of the colon induced by DMH an increased binding of 125J-EGF has been observed as compared with normal colonic enterocytes and increased number of EGF-R was clearly demonstrated. Phosphorylation of p34 in the intestinal membranes proceeds much more intensively than that of EGF-R.
mesh_terms: D019813:1,2-Dimethylhydrazine; D000818:Animals; D002273:Carcinogens; D002462:Cell Membrane / Q000201:enzymology; D004064:Digestive System / Q000201:enzymology*; D004127:Dimethylhydrazines; D004815:Epidermal Growth Factor / Q000378:metabolism*; D004848:Epithelium / Q000201:enzymology; D066246:ErbB Receptors / Q000032:analysis* / Q000378:metabolism; D007414:Intestinal Neoplasms / Q000032:analysis* / Q000139:chemically induced / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008297:Male; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats
chemical_list: D002273:Carcinogens; D004127:Dimethylhydrazines; D004815:Epidermal Growth Factor; D011494:Protein Kinases; D066246:ErbB Receptors; D019813:1,2-Dimethylhydrazine
vernacular_title: Kharakteristika retseptorov épidermal'nogo faktora rosta v épitelii zheludochno-kishechnogo trakta krys i v opukholiakh kishechnika, indutsirovannykh 1,2-dimetilgidrazinom.