Disposition and Toxicity of 2,2’,5,5’-Tetrachlorobiphenyl in Female Rats Following Intraperitoneal Exposure

The disposition and toxicity of lower chlorinated PCBs (LC-PCBs) with less than five chlorine substituents have received little attention to date. This study characterizes the distribution of PCB 52, an LC-PCB found in indoor and outdoor air, three weeks after intraperitoneal exposure of female Sprague Dawley rats to 0, 1, 10, or 100 mg PCB 52/kg BW. PCB 52 exposure did not affect body or organ weights. PCB 52, measured using gas chromatography-tandem mass spectrometry (GC-MS/MS), was detected in all tissue. Hydroxylated, sulfated, and methylated PCB metabolites, identified using GC-MS/MS and nontarget liquid chromatography-high resolution mass spectrometry, were primarily found in the serum and liver of rats exposed to 100 mg/kg BW. Metabolomic analysis revealed minor effects on L-cysteine, glycine, cytosine, sphingosine, thymine, linoleic acid, orotic acid, L-histidine, and erythrose serum levels. Based on these results, PCB 52 toxicity studies need to account for its complex metabolism in vivo . ![Figure][1] Highlights ### Competing Interest Statement The authors have declared no competing interest. * IP : intraperitoneal PCB : polychlorinated biphenyl BW : body weight Nt-LCMS : Nontarget; liquid chromatography-high resolution mass spectrometric GC-MS/MS : Gas chromatograph mass spectrometric UPLC-QTof-MS : Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometric QC : quality control PCA : principle component analysis ANOVA : analysis of variance DA : dopamine DOPAC : 3,4-Dihydroxyphenylacetic acid DOPAL : 3,4-dihydroxyphenylacetaldehyde PLS-DA : partial least squares-discriminant analysis (PLS-DA) VIP : variable importance in projection CYP : cytochrome P450 enzyme SD : Sprague-Dawley MOC : methyoxyamine hydrochloride TMS : N,O-Bis(trimethylsilyl)trifluoroacetamide SPE : solid phase extraction SULT : sulfotransferase COMT : catechol-O-methyltransferase ND : non-detect [1]: pending:yes