title: Penetration of nalidixic acid into Escherichia coli K-12 cells.
abstract: Transport of nalidixic acid (NAL) into Escherichia coli cells subjected to osmotic shock, permeabilised with toluene or treated with DNP, CCCP or EDTA, was studied. It was found that osmotic shock and protonophores do not inhibit the transport of [3H]NAL, however, the transport of [3H]DAP and [3H]glucose is reduced. EDTA and toluene enhance penetration of [3H]NAL. This effect is, however, abolished in the presence of Mg++ ions. It is suggested that NAL penetrates into the cell by simple or facilitated diffusion and that the outer membrane of E. coli is the penetration barrier for the drug.
mesh_terms: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D004140:Dinitrophenols / Q000494:pharmacology; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D009268:Nalidixic Acid / Q000378:metabolism*; D009997:Osmotic Pressure; D014050:Toluene / Q000378:metabolism
chemical_list: D004140:Dinitrophenols; D009268:Nalidixic Acid; D014050:Toluene; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D004492:Edetic Acid; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D005947:Glucose; D005990:Glycerol