title: Uptake of flurithromycin by human polymorphonuclear phagocytes: partial characterization of the entry mechanism.
abstract: The ability of flurithromycin and erythromycin to enter human polymorphonuclear phagocytes were studied and compared by a velocity centrifugation gradient technique. Both macrolides were markedly concentrated by human cells and attained cellular to extracellular concentration ratios (C/E) > or = 10. The incorporation was rapid and essentially complete after 60 min incubation. When PMNs were pretreated with formaldehyde, or incubated at low temperatures (4-25 degrees C) or at low pH, the transport ratios of both molecules were reduced. Sodium fluoride and 2,4-dinitrophenol, which decreased erythromycin uptake, did not affect flurithromycin penetration. Perturbation of cell membrane by phorbol myristate acetate, but not by formyl methionyl leucyl peptide, affected C/E ratios of both antibiotics. The addition of amino acids or nucleosides did not influence their transfer into PMNs.
authors.affiliation: University of Pavia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fietta
authors.forename: P
authors.initials: P
authors.lastname: Boeri
authors.forename: M L
authors.initials: ML
authors.lastname: Colombo
authors.forename: C
authors.initials: C
authors.lastname: Merlini
authors.forename: G
authors.initials: G
authors.lastname: Gialdroni Grassi
mesh_terms: D000328:Adult; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D009504:Neutrophils / Q000378:metabolism*
chemical_list: C045925:flurithromycin; D004917:Erythromycin