title: Exposure to low- vs iso-osmolar contrast agents reduces NADPH-dependent reactive oxygen species generation in a cellular model of renal injury.
abstract: Contrast-induced nephropathy represents the third cause of hospital-acquired acute renal failure. This study investigated the effects of low- vs iso-osmolar contrast medium (CM) exposure on NADPH-dependent reactive oxygen species (ROS) generation by tubular cells. X-ray attenuation of iohexol, iopamidol, and iodixanol was assessed at equimolar iodine concentrations and their effects on human renal proximal tubular cells (PTCs) were evaluated with equally attenuating solutions of each CM. Cytotoxicity, apoptosis, and necrosis were investigated by trypan blue exclusion, MTT assay, and annexin V/propidium iodide assay, respectively. ROS production was assessed by DCF assay, NADPH oxidase activity by the lucigenin-enhanced chemiluminescence method, and Nox4 expression by immunoblot. Yielding the same X-ray attenuation, CM cytotoxicity was assessed in PTCs at equimolar iodine concentrations. More necrosis was present after incubation with iohexol and iopamidol than after incubation with equal concentrations of iodixanol. Iohexol and iodixanol at low iodine concentrations induced less cytotoxicity than iopamidol. Moreover, both iohexol and iopamidol induced more apoptosis than iodixanol, with a dose-dependent effect. ROS generation was significantly higher with iopamidol and iohexol compared to iodixanol. NADPH oxidase activity and Nox4 protein expression significantly increased after exposure to iopamidol and iohexol, with a dose-dependent effect, compared with iodixanol. CM-induced Nox4 expression and activity depended upon Src activation. In conclusion, at angiographic concentrations, iodixanol induces fewer cytotoxic effects on cultured tubular cells than iohexol and iopamidol along with a lower induction of Nox4-dependent ROS generation. This enzyme may, thus, represent a potential therapeutic target to prevent iodinated CM-related oxidative stress.
authors.affiliation: Department of Medical and Surgical Sciences, Section of Clinical Pathology, University of Foggia, Foggia 71122, Italy.
authors.forename: Giuseppe Stefano
authors.initials: GS
authors.lastname: Netti
authors.affiliation: Department of Medical and Surgical Sciences, Section of Clinical Pathology, University of Foggia, Foggia 71122, Italy.
authors.forename: Clelia
authors.initials: C
authors.lastname: Prattichizzo
authors.affiliation: Department of Medical and Surgical Sciences, Section of Nephrology, University of Foggia, Foggia 71122, Italy.
authors.forename: Eustacchio
authors.initials: E
authors.lastname: Montemurno
authors.affiliation: Department of Emergency and Organ Transplantation, Section of Nephrology, University of Bari "Aldo Moro," Bari 70124, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Simone
authors.affiliation: Department of Emergency and Organ Transplantation, Section of Nephrology, University of Bari "Aldo Moro," Bari 70124, Italy.
authors.forename: Cesira
authors.initials: C
authors.lastname: Cafiero
authors.affiliation: Department of Medical and Surgical Sciences, Section of Nephrology, University of Foggia, Foggia 71122, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Rascio
authors.affiliation: Department of Medical and Surgical Sciences, Section of Nephrology, University of Foggia, Foggia 71122, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Stallone
authors.affiliation: Department of Medical and Surgical Sciences, Section of Clinical Pathology, University of Foggia, Foggia 71122, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Ranieri
authors.affiliation: Department of Medical and Surgical Sciences, Section of Nephrology, University of Foggia, Foggia 71122, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Grandaliano
authors.affiliation: Department of Emergency and Organ Transplantation, Section of Nephrology, University of Bari "Aldo Moro," Bari 70124, Italy. Electronic address: loreto.gesualdo@uniba.it.
authors.forename: Loreto
authors.initials: L
authors.lastname: Gesualdo
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced / Q000473:pathology*; D017209:Apoptosis / Q000187:drug effects; D003287:Contrast Media / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D007472:Iohexol / Q000008:administration & dosage; D007479:Iopamidol / Q000008:administration & dosage; D007668:Kidney / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology*; D009249:NADP / Q000378:metabolism; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism; D009336:Necrosis; D011859:Radiography; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014283:Triiodobenzoic Acids / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D017382:Reactive Oxygen Species; D014283:Triiodobenzoic Acids; D007472:Iohexol; D009249:NADP; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; C044834:iodixanol; D007479:Iopamidol
keywords: Contrast-induced nephropathy; Free radicals; Iso-osmolar contrast medium; Low-osmolar contrast medium; NADPH oxidase; Reactive oxygen species