title: The release of cytosolic proteins from cells treated with concanavalin A during scraping from plastic culture dishes.
abstract: When rat hepatoma cells (HTC and R117-21B), treated with concanavalin A (conA) at 37 degrees C, were scraped from plastic culture dishes with a silicone-rubber policeman, the cell membranes were broken and the cytoplasm was released. This phenomenon was also observed in cells treated with conA at 4 degrees C, even though it took a longer time to show the same effect. The effect of 10 micrograms/ml of conA on the release of the cellular proteins reached a plateau when the treatment was carried out at 37 degrees C. Ninety percent of this effect was abolished by 10 mM of alpha-methyl-D-mannoside. The effect was completely nullified by 100 mM. At 4 degrees C, however, even 100 mM of this sugar could not abolish this effect. The apparent decrease in the cellular proteins with conA after scraping was observed not only in the logarithmic phase, but also in the stationary phase of cell growth. The breakdown of plasma membranes with conA eventually caused decrease in tyrosine aminotransferase activity, even though the lectin induced the enzyme activity in cultured cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D003208:Concanavalin A / Q000494:pharmacology*; D003584:Cytological Techniques; D003600:Cytosol / Q000032:analysis*; D004790:Enzyme Induction; D008114:Liver Neoplasms, Experimental; D008766:Methylmannosides / Q000494:pharmacology; D011506:Proteins / Q000032:analysis*; D051381:Rats; D014444:Tyrosine Transaminase / Q000378:metabolism*
chemical_list: D008766:Methylmannosides; D011506:Proteins; D003208:Concanavalin A; C008466:methylmannoside; D014444:Tyrosine Transaminase