title: Interactions of ultrapure bovine hemoglobin with renal epithelial cells in vivo and in vitro.
abstract: Using an ultrapurified hemoglobin (Hb) solution, we investigated the physiological effects and cellular processing of Hb in rat kidneys and in cultured opossum kidney (OK) cells. Rats infused with < 5.0 g/kg Hb showed no change in baseline serum creatinine (SCr) values (0.58 +/- 0.05 mg/dl) over 48 h, whereas transient acute renal failure followed infusion of 7.5 g/kg Hb (SCr 3.4 +/- 1.02 mg/dl, P = 0.02). Histology of Hb-infused kidneys demonstrated tubular epithelial cell injury. Renal injury was not caused by volume or oncotic load, cardiovascular effect, or ATP depletion. After Hb infusion, heme oxygenase, the rate-limiting enzyme in Hb catabolism, was induced in an organ-specific fashion. Inhibiting heme oxygenase activity with cimetidine did not alter Hb renal injury. Using OK cells, we determined that renal epithelia process Hb by fluid-phase endocytosis. Proton permeability of fluorescein Hb endosomes was unaltered compared with fluorescein dextran controls, demonstrating that Hb does not alter endosomal membrane integrity. These data suggest that Hb renal injury in rats occurs following large doses of ultrapure Hb, does not alter early steps in Hb endosomal processing by renal epithelia, and involves a mechanism that is not heme oxygenase dependent.
authors.affiliation: Division of Nephrology, Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: M
authors.initials: M
authors.lastname: Somers
authors.forename: A I
authors.initials: AI
authors.lastname: Piqueras
authors.forename: K
authors.initials: K
authors.lastname: Strange
authors.forename: M L
authors.initials: ML
authors.lastname: Zeidel
authors.forename: W
authors.initials: W
authors.lastname: Pfaller
authors.forename: M
authors.initials: M
authors.lastname: Gawryl
authors.forename: H W
authors.initials: HW
authors.lastname: Harris
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D002417:Cattle; D002460:Cell Line; D002927:Cimetidine / Q000494:pharmacology; D003404:Creatinine / Q000097:blood; D003911:Dextrans; D004705:Endocytosis; D011992:Endosomes / Q000187:drug effects / Q000648:ultrastructure; D004790:Enzyme Induction; D004848:Epithelium / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D005919:Glomerular Filtration Rate; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis; D006454:Hemoglobins / Q000302:isolation & purification / Q000493:pharmacokinetics* / Q000633:toxicity*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D009893:Opossums; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D003911:Dextrans; D006454:Hemoglobins; C015219:fluorescein isothiocyanate dextran; D002927:Cimetidine; D003404:Creatinine; D006419:Heme Oxygenase (Decyclizing); D016650:Fluorescein-5-isothiocyanate