β-Oxidation of 2-ethyl-5-carboxypentyl phthalate in rodent liver

Phillip W. Albro*, Jean T. Corbett, Joanna Schroeder, Janardan K. Reddy

*Corresponding author for this work

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

[7-14C]2-Ethyl-5-carboxypentyl phthalate was isolated and purified from urine of rats given [7-14C]-di-(2-ethylhexyl) phthalate. This metabolite was shown to serve as a precursor for 2-ethyl-3-carboxypropylphthalate in vivo. 2-Ethyl-5-carboxypentyl phthalate was oxidized to 2-ethyl-3-carboxypropyl phthalate in liver slices from control or, much more rapidly, from clofibrate-pretreated rats. Inhibition by KCN in liver slices from untreated rats, and strong inhibition by acrylate, suggested that formation of 2-ethyl-3-carboxy-propyl phthalate involved mitochondria β-oxidation. The strong enhancement of the product of this compound by clofibrate (a very weak inducer for mitochondrial dehydrogenases), and strong inhibition by chlorpromazine suggested that peroxisomes may also be able to oxidize 2-ethyl-5-carboxypentyl phthalate. We were able to detect β-oxidation of 2-ethyl-5-carboxypentyl phthalate to 2-ethyl-3-carboxypropyl phthalate using purified mitochondria, but strong phthalate monoester hydrolase activity observed during incubation of the former compound with purified peroxisomes made it impossible to determine whether 2-ethyl-3-carboxypropyl phthalate could be produced in the latter organelle or not. 2-Ethyl-5-carboxypentyl phthalate was such an inefficient substrate for β-oxidation compared to palmitic acid that it is unlikely that it contributes significantly to the production of H2O2 in rats chronically exposed to di-(2-ethylhexyl) phthalate. Normal fatty acids are most likely to serve as the dominat substrates for peroxisomal β-oxidase.

Original languageEnglish (US)
Pages (from-to)196-205
Number of pages10
JournalBBA - General Subjects
Volume923
Issue number2
DOIs
StatePublished - Feb 20 1987

Keywords

  • (Rat liver)
  • Mitochondrion
  • Peroxisome
  • Phthalate
  • β-oxidation

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

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  • Cite this

    Albro, P. W., Corbett, J. T., Schroeder, J., & Reddy, J. K. (1987). β-Oxidation of 2-ethyl-5-carboxypentyl phthalate in rodent liver. BBA - General Subjects, 923(2), 196-205. https://doi.org/10.1016/0304-4165(87)90004-3