title: Nucleotide depletion increases trafficking of gentamicin to the Golgi complex in LLC-PK1 cells.
abstract: Having shown rapid trafficking of aminoglycosides to the Golgi complex in cell culture, we focused on the injurious interaction that occurs when gentamicin administration is preceded by renal ischemia. Using Texas red-labeled gentamicin as a tracer, we determined that 15 min of cellular nucleotide depletion did not significantly increase subsequent uptake. However, cells previously depleted of nucleotides accumulated significantly more Texas red-labeled gentamicin within a dispersed Golgi complex. Using Ricinus communis and Lens culinaris lectins, which label specific compartments of the Golgi complex (trans-Golgi network/trans and medial/cis compartments, respectively), we determined that the medial/cis compartment dispersed after 15 min of nucleotide depletion but the trans-Golgi network/trans compartment remained unaffected. An increase in the number of cells exhibiting disrupted medial/cis-Golgi morphology after repletion in physiological media containing gentamicin was also seen. In summary, the increase in nephrotoxicity seen when ischemia precedes aminoglycoside uptake may be part of a complex mechanism initially involving increased Golgi accumulation and prolonged Golgi dispersion. The Golgi complex must then endure the effects of gentamicin accumulated in larger quantities in an aberrant physiological state.
authors.affiliation: Department of Medicine, Division of Nephrology, Indiana University School of Medicine and Roudebush Veterans Administration Medical Center, Indianapolis, Indiana 46202, USA.
authors.forename: Ruben M
authors.initials: RM
authors.lastname: Sandoval
authors.forename: Robert L
authors.initials: RL
authors.lastname: Bacallao
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Dunn
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Leiser
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Molitoris
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D005839:Gentamicins / Q000493:pharmacokinetics*; D006056:Golgi Apparatus / Q000378:metabolism*; D007511:Ischemia / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D018374:LLC-PK1 Cells; D009711:Nucleotides / Q000172:deficiency*; D012079:Renal Circulation; D013552:Swine; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D009711:Nucleotides