title: The mechanism of pentachlorobutadienyl-glutathione nephrotoxicity studied with isolated rat renal epithelial cells.
abstract: Isolated renal epithelial cells were used to study the mechanism of toxicity of pentachlorobutadienyl-glutathione (PCBG), a nephrotoxic glutathione conjugate of hexachlorobutadiene. The cytotoxicity of PCBG displayed a very steep dose-response relationship; at 10 microM PCBG no toxicity was observed whereas 25, 50, and 100 microM PCBG all resulted in a similar degree of toxicity. In all cases, loss of cell viability was observed only after a 30-min lag period and reached a plateau of 50 to 60% nonviable cells between 90 and 100 min. Toxic doses of PCBG also resulted in the depletion of cellular thiols. Blocking PCBG metabolism by inhibition of gamma-glutamyl transpeptidase [1-gamma-L-glutamyl-2-(2-carboxyphenyl)hydrazine (anthglutin), 2 mM] or renal cysteine conjugate beta-lyase (aminooxyacetic acid, 0.5 mM) resulted in complete protection against PCBG-induced cell damage. Exposure of isolated renal epithelial cells to 100 microM PCBG resulted in the rapid formation of plasma membrane blebs which appeared to be associated with a loss of Ca2+ from the mitochondrial compartment and an elevation of cytosolic Ca2+ concentration as measured by Quin-2. PCBG treatment also resulted in the inhibition of cell respiration and a marked depletion of cellular ATP content, indicating additional mitochondrial effects of the toxin. Our results support a role for renal cysteine conjugate beta-lyase in the metabolic activation of PCBG and suggest that PCBG-induced renal cell injury may be the result of selective effects on mitochondrial function.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000634:Aminoquinolines; D000818:Animals; D002070:Butadienes / Q000037:antagonists & inhibitors / Q000633:toxicity*; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005456:Fluorescent Dyes; D005978:Glutathione / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000633:toxicity; D066298:In Vitro Techniques; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000634:Aminoquinolines; D002070:Butadienes; D005456:Fluorescent Dyes; C050500:S-(1,2,3,4,4-pentachloro-1,3-butadienyl)glutathione; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D005978:Glutathione; C035739:Quin2; D002118:Calcium