Enzymatic conjugation of hexachloro-1,3-butadiene with glutathione. Formation of 1-(glutathion-S-yl)-1,2,3,4,4-pentachlorobuta-1,3-diene and 1,4-bis(glutathion-S-yl)-1,2,3,4-tetrachlorobuta-1,3-diene.
The glutathione-dependent metabolism of the nephrotoxin and nephrocarcinogen hexachloro-1,3-butadiene (HCBD) was investigated in subcellular fractions from rat liver and kidney. HCBD was metabolized by hepatic glutathione S-transferases to (E)- and (Z)-1-(glutathion-S-yl)-pentachlorobuta-1,3-diene (GPCB) in a ratio of 20:1, which were identified by secondary ion MS and by GC-MS after acid hydrolysis. The formation of GPCB was dependent on time and on protein and glutathione concentrations. Microsomal glutathione S-transferases from rat liver catalyzed GPCB formation more efficiently than did cytosolic glutathione S-transferases; very low rates of GPCB formation were observed in kidney subcellular fractions. GPCB is also a substrate for glutathione S-transferases and is metabolized to a diglutathione conjugate, which was identified by secondary ion MS and 13C NMR spectrometry as 1,4-bis(glutathion-S-yl)-1,2,3,4-tetrachlorobuta-1,3-diene (BTCB). BTCB formation from GPCB was dependent on time and on protein, glutathione, and GPCB concentrations. Hepatic cytosol catalyzed BTCB formation more efficiently than did hepatic microsomes; significant amounts of BTCB were also formed in kidney cytosol. Hepatic formation of glutathione S-conjugates, translocation of the S-conjugates to the kidney, and renal processing to form reactive intermediates may be the cause of HCBD-induced nephrotoxicity and, perhaps, nephrocarcinogenicity.
Dekant
W
W
Department of Pharmacology, University of Rochester, NY 14642.
Vamvakas
S
S
Henschler
D
D
Anders
M W
MW
D000818:Animals; D001711:Biotransformation; D002070:Butadienes / Q000302:isolation & purification* / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid; D005659:Fungicides, Industrial / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D005978:Glutathione / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D008861:Microsomes / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D002070:Butadienes; D002250:Carbon Radioisotopes; D005659:Fungicides, Industrial; C057943:1,4-bis(glutathion-S-yl)-1,2,3,4-tetrachlorobuta-1,3-diene; C050500:S-(1,2,3,4,4-pentachloro-1,3-butadienyl)glutathione; C001335:hexachlorobutadiene; D005978:Glutathione