IMMUNE CHEMICAL-ANALYSIS OF QUINOL-THIOETHER-DERIVED COVALENT PROTEINADDUCTS IN RODENT SPECIES SENSITIVE AND RESISTANT TO QUINOL-THIOETHER-MEDIATED NEPHROTOXICITY

2,3,5-Tris(glutathion-S-yl)hydroquinone (TGHQ) is nephrotoxic in male Fischer 344 rats (20 mu mol/kg) and albino guinea pigs (200 mu mol/kg) , but not BALB/c or B6C3F(1) mice or Golden Syrian hamsters (200 mu mo l/kg). Since quinones are known to alkylate proteins, and because such macromolecular damage may play a role in cytotoxicity, we investigate d the covalent binding of TGHQ to kidney (target tissue) and liver (no ntarget tissue) of rodents ''sensitive'' or ''resistant'' to the nephr otoxic effects of TGHQ. Immunohistochemical staining of tissue obtaine d 2 h after administration of TGHQ, with rabbit anti-2-bromo-N-(acetyl -L-cystein-S-yl)HQ antibodies, correlated with the subsequent region o f necrosis observed 19 h after dosing in Fischer 344 rats and guinea p igs. Immunohistochemical staining was localized to the Sg segment of t he renal proximal tubules, at the corticomedullary junction along the medullary rays, and in the outer stripe of the outer medulla. Immunost aining was also observed in the same region in hamsters, but subsequen t necrosis did not develop. In contrast, no immunostaining was observe d in mice. Moreover, immunostaining was not detected in the livers of any species. Western blot analysis revealed numerous immunoreactive re nal proteins in TGHQ-treated animals. The most distinctive immunostain ing renal proteins were observed in Fischer 344 rats at similar to 34 kDa (mitochondria), similar to 35 kDa (nuclei) which comigrated with h istone H1, and similar to 73 kDa (urine) which comigrated with gamma-g lutamyl transpeptidase. These adducted proteins were not detected in o ther species. Qualitative differences in alkylated proteins may theref ore contribute to species susceptibility to TGHQ.