LLC-PK1 cells as a model for renal toxicity caused by arsine exposure.
The mechanisms of arsine (AsH3) toxicity are not completely understood. Studies were undertaken to determine AsH3 and arsenite [As(III)] toxicity in a renal tubular epithelial cell line to model kidney dysfunction caused by AsH3 exposure. The hypothesis was that As(III) is the toxic metabolite responsible for the renal toxicity of AsH3. There was a concentration- and time-dependent toxic response after As(III) incubation. As(III) produced significant LDH leakage as early as 1 h and intracellular potassium loss at 5 h. AsH3 produced no changes in these parameters. AsH3 affected neither potassium nor LDH levels over 24 h and up to 1 mM AsH3 concentration. In this system, As(III) induced LDH leakage before K+ loss. Oxidative stress-like toxicity effects were also studied by determining levels of glutathione (GSH), glutathione disulfide (GSSG), and heat-shock protein 32 (Hsp32) levels. GSH levels were not markedly affected by any arsenical over a 6-h period or up to 100 microM concentration of the arsenical. However, 100 microM AsH3 significantly increased GSSG levels as early as 30 min and reached a maximum at 2.5 h. Incubation with 10 microM AsH3 was sufficient to significantly increase GSSG levels. As(III) had no marked effect on GSSG. Both arsenicals (50 microM) produced a slight increase (about threefold) in Hsp32 levels after 4-h incubation. These results showed that unchanged AsH3 produced oxidative stress-like toxic effects without producing cell death. However, similar As(III) concentrations induced the stress response and were toxic to the cells. These data indicated that AsH3 is not directly toxic to LLC-PK1 cells.
Ayala-Fierro
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Department of Pharmacology and Toxicology, Center for Toxicology, College of Pharmacy, University of Arizona, Tucson 85721, USA. ayala@pharmacy.arizona.edu
Carter
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D000818:Animals; D001152:Arsenicals / Q000009:adverse effects*; D018053:Arsenites / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000032:analysis; D019803:Glutathione Disulfide / Q000032:analysis; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis; D051547:Heme Oxygenase-1; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000187:drug effects*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D018374:LLC-PK1 Cells; D008565:Membrane Proteins; D011188:Potassium / Q000032:analysis; D013552:Swine
D001152:Arsenicals; D018053:Arsenites; D008565:Membrane Proteins; D007770:L-Lactate Dehydrogenase; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D005978:Glutathione; C015001:arsenite; D011188:Potassium; D019803:Glutathione Disulfide; C006633:arsine