RT Journal Article SR Electronic T1 Halothane metabolism: immunochemical evidence for molecular mimicry of trifluoroacetylated liver protein adducts by constitutive polypeptides. JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 390 OP 400 VO 40 IS 3 A1 Christen, U A1 Bürgin, M A1 Gut, J YR 1991 UL http://molpharm.aspetjournals.org/content/40/3/390.abstract AB A monoform antibody [anti-TFA antibody] against TFA-protein adducts (TFA-adducts) was obtained by affinity purification of a polyclonal antiserum, raised in rabbits against TFA-rabbit serum albumin, on a N-epsilon-TFA-L-lysine matrix coupled to Affi-Gel 102. The anti-TFA antibody did recognize TFA-adducts of distinct molecular mass on Western blots of hepatocyte homogenates or microsomal membranes obtained from rats pretreated with halothane. The anti-TFA antibody also recognized cross-reactive polypeptides with apparent molecular masses of 52 kDa and 64 kDa on Western blots of hepatocyte homogenates obtained from rats not treated with halothane or metabolites thereof. The 52-kDa and 64-kDa cross-reactive polypeptides were localized in the 3,000 x g particulate fraction of liver homogenates. Recognition, on Western blots, of TFA-adducts and both the 52-kDa and 64-kDa cross-reactive polypeptides by anti-TFA antibody was sensitive to competition by N-epsilon-TFA-L-lysine (IC50 less than 100 microM) and N-epsilon-acetyl-L-lysine (IC50 approximately 10 mM). Treatment with piperidine (1 M) did abolish the recognition of TFA-adducts but not that of the 52-kDa and the 64-kDa cross-reactive polypeptides by anti-TFA antibody on Western blots. In antibody-exchange experiments, anti-TFA antibody was affinity-adsorbed on Western blots to the 52-kDa or the 64-kDa cross-reactive polypeptides of the rat heart, followed by spontaneous transfer to target TFA-adducts present on Western blots of rat liver microsomal membranes. The majority of these target TFA-adducts were recognized by anti-TFA antibody transferring from the source 52-kDa or 64-kDa cross-reactive polypeptides. When examined up to 10 days after exposure of rats to a single dose of halothane, no influence on the constitutive level of expression, in the liver, of either cross-reactive polypeptide was observed. In contrast, TFA-adducts were persistent for greater than 90 hr but less than 10 days. In addition to the liver, the 52-kDa and the 64-kDa cross-reactive polypeptides were prominently expressed in the heart and the kidney and, to a much lesser degree, in the spleen, the thymus, the lung, and skeletal muscle of the rat. Considerable variation in the level of expression of the 52-kDa and the 64-kDa cross-reactive polypeptides was recognized in livers of the six human individuals tested so far.(ABSTRACT TRUNCATED AT 250 WORDS)