title: Hypoxia-reoxygenation inhibits gap junctional communication in cultured human umbilical vein endothelial cells.
abstract: We studied the change in gap junctional intercellular communication (GJIC) on human umbilical vein endothelial cells (HUVEC) under hypoxia-reoxygenation (H-R) conditions by the fluorescence redistribution after photobleaching (FRAP) method. Confluent HUVEC monolayers were exposed to hypoxia (pO2<0.1%) for 12 hours, and then were returned to normal atmospheric conditions for reoxygenation. Contrast microscopic observation showed no significant changes in the morphology of the HUVEC at any times after H-R. Reoxygenation following hypoxia caused time-dependent decrease in GJIC, that is, GJIC reduction was induced after 2 hours and reached maximum at 4-6 hours which recovered to normal levels after 18 hours. Oxidant sensitive fluorescence dye assay revealed that the generation of intracellular free radicals increased during the first 2 hours after reoxygenation. Hydroxyl radical scavengers (MCI-186, DMSO) and an iron chelator (deferoxamine) abolished the reduction of GJIC due to H-R. However, SOD, catalase and probucol were essentially inactive on this reduction. These data suggest that ischemia-reperfusion injury may be caused by a functional defect of GJIC induced by reactive oxygen radicals.
authors.affiliation: Department of Cellular Physiological Chemistry, Graduate School, Tokyo Medical and Dental University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nishida
authors.forename: S
authors.initials: S
authors.lastname: Futami
authors.forename: I
authors.initials: I
authors.lastname: Morita
authors.forename: K
authors.initials: K
authors.lastname: Maekawa
authors.forename: S I
authors.initials: SI
authors.lastname: Murota
mesh_terms: D000983:Antipyrine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D002450:Cell Communication; D015687:Cell Hypoxia; D002478:Cells, Cultured; D003676:Deferoxamine / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D000077553:Edaravone; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D017629:Gap Junctions / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D019044:Image Cytometry / Q000379:methods; D007834:Lasers; D010100:Oxygen / Q000502:physiology*; D011341:Probucol / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors; D014471:Umbilical Veins / Q000166:cytology / Q000502:physiology
chemical_list: D017382:Reactive Oxygen Species; D002374:Catalase; D013482:Superoxide Dismutase; D003676:Deferoxamine; D011341:Probucol; D000077553:Edaravone; D010100:Oxygen; D000983:Antipyrine; D004121:Dimethyl Sulfoxide