Catabolism of isobutyrate by colonocytes

Jerzy Jaskiewicz, Yu Zhao, John W. Hawes, Y. Shimomura, David W. Crabb, Robert A. Harris

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

Isolated colonocytes have more capacity for the oxidation of isobutyrate and α-ketoisovalerate than isolated enterocytes. Both enterocytes and colonocytes express high levels of 3-hydroxyisobutyryl-CoA hydrolase, an enzyme activity important in maintaining low intracellular concentrations of methacrylyl-CoA, a common, potentially toxic intermediate in the catabolic pathways of these compounds. In spite of comparable 3-hydroxyisobutyryl-CoA hydrolase activities in both cell types, and much greater amounts of 3- hydroxyisobutyrate dehydrogenase in colonocytes than in enterocytes, only the colonocytes produced 3-hydroxyisobutyrate as an endproduct of α- ketoisovalerate and isobutyrate catabolism. Butyrate very effectively inhibits isobutyrate catabolism by colonocytes, most likely by competitively inhibiting activation of isobutyrate to its CoA ester. Oleate also inhibits isobutyrate catabolism, but at a site more distal than butyrate. Starvation of rats for 72 h decreased the capacity of colonocytes for butyrate but not isobutyrate catabolism. We conclude that isobutyrate could function as a carbon source for energy and anapleurosis in colonocytes under conditions of defective butyrate oxidation or low butyrate availability.

Original languageEnglish (US)
Pages (from-to)265-270
Number of pages6
JournalArchives of Biochemistry and Biophysics
Volume327
Issue number2
DOIs
StatePublished - Mar 15 1996

Keywords

  • 3-hydroxyisobutyrate
  • 3-hydroxyisobutyryl-CoA hydrolase
  • branched-chain α-ketoacid dehydrogenase
  • butyrate
  • colon
  • colonocytes
  • enterocytes
  • glucose
  • isobutyrate
  • ketone bodies
  • starvation
  • valine

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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