title: Association of nitric oxide production by kidney proximal tubular cells in response to lipopolysaccharide and cytokines with cellular damage.
abstract: Recent findings suggest that nitric oxide (NO) is an important biologic mediator which exerts a wide variety of effects on numerous physiological and pathophysiological processes. L-Arginine is oxidized to L-citrulline with concomitant NO production; as a result, nitrate and nitrite accumulates. This study was conducted to determine the potential NO production by proximal tubular cells (PTC) in response to bacterial lipopolysac-charides (LPS) and cytokines and to evaluate the cytotoxic effect associated with NO release. After a 7-day stimulation with LPS (100 micrograms/ml), interleukin-1 beta (IL-1 beta) (10 ng/ml), and tumor necrosis factor alpha (TNF-alpha) (10 ng/ml), the nitrate and nitrite levels were determined by a spectrophotometric method based on the Griess reaction. Moreover, alpha-methylglucopyranoside phosphate and lactate dehydrogenase release and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay served as indicators of sodium-dependent hexose transport integrity and cell death, respectively. IL-1 beta and TNF-alpha used alone or together or combined with LPS led to a significant generation of NO by PTC. Our results also demonstrate that NO induced by LPS and cytokines could inhibit sodium-dependent transport and could induce PTC damage.
authors.affiliation: Centre de Recherche du Centre Hospitalier de l'Université Laval, Départment de Microbiologie, Faculté de Médecine, Université Laval, Québec, Canada.
authors.forename: A F
authors.initials: AF
authors.lastname: Kaboré
authors.forename: M
authors.initials: M
authors.lastname: Denis
authors.forename: M G
authors.initials: MG
authors.lastname: Bergeron
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003124:Colorimetry; D004396:Coloring Agents; D016207:Cytokines / Q000494:pharmacology*; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000494:pharmacology; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000378:metabolism; D011817:Rabbits; D012964:Sodium / Q000502:physiology; D013778:Tetrazolium Salts; D013844:Thiazoles; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D004396:Coloring Agents; D016207:Cytokines; D007375:Interleukin-1; D008070:Lipopolysaccharides; D009566:Nitrates; D009573:Nitrites; D013778:Tetrazolium Salts; D013844:Thiazoles; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D012964:Sodium; D007770:L-Lactate Dehydrogenase; C022616:thiazolyl blue