PT - JOURNAL ARTICLE AU - Sanderson, L. AU - Taylor, G. W. AU - Aboagye, E. O. AU - Alao, J. P. AU - Latigo, J. R. AU - Coombes, R. C. AU - Vigushin, D. M. TI - PLASMA PHARMACOKINETICS AND METABOLISM OF THE HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A AFTER INTRAPERITONEAL ADMINISTRATION TO MICE AID - 10.1124/dmd.104.000638 DP - 2004 Oct 01 TA - Drug Metabolism and Disposition PG - 1132--1138 VI - 32 IP - 10 4099 - http://dmd.aspetjournals.org/content/32/10/1132.short 4100 - http://dmd.aspetjournals.org/content/32/10/1132.full SO - Drug Metab Dispos2004 Oct 01; 32 AB - Trichostatin A is a potent and specific histone deacetylase inhibitor with promising antitumor activity in preclinical models. Plasma pharmacokinetics of trichostatin A were studied following single-dose intraperitoneal administration of 80 mg/kg (high dose) or 0.5 mg/kg (low dose) to female BALB/c mice. Plasma trichostatin A concentrations were quantified by high performance liquid chromatography (HPLC)-UV assay (high dose) or by HPLC-multiple reaction monitoring assay (low dose). Trichostatin A was rapidly absorbed from the peritoneum and detectable in plasma within 2 min. Cmax of 40 μg/ml and 8 ng/ml occurred within 5 min, followed by rapid exponential decay in plasma trichostatin A concentration with t1/2 of 6.3 min and 9.6 min (high and low doses, respectively). Phase I metabolites at the high dose were identified by simultaneous UV and positive ion electrospray mass spectrometry. Trichostatin A underwent extensive metabolism: primary metabolic pathways were N-demethylation, reduction of the hydroxamic acid to the corresponding trichostatin A amide, and oxidative deamination to trichostatic acid. N-Monomethyl trichostatin A amide was the major plasma metabolite. No didemethylated compounds were identified. Trichostatic acid underwent further biotransformation: reduction and β-oxidation of the carboxylic acid, with or without N-demethylation, resulted in formation of dihydro trichostatic acid and dinor dihydro trichostatic acids. HPLC fractions corresponding to trichostatin A and N-demethylated trichostatin A exhibited histone deacetylase-inhibitory activity; no other fractions were biologically active. We conclude that trichostatin A is rapidly and extensively metabolized in vivo following intraperitoneal administration to mice, and N-demethylation does not compromise histone deacetylase-inhibitory activity. The American Society for Pharmacology and Experimental Therapeutics