Interactions between dehydroepiandrosterone and glucocorticoid metabolism in pig kidney: nuclear and microsomal 11beta-hydroxysteroid dehydrogenases

Arch Biochem Biophys. 2005 Oct 1;442(1):33-40. doi: 10.1016/j.abb.2005.07.010.

Abstract

The 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) activates glucocorticoids (GC) by reversibly converting 11-keto-GC to 11-hydroxy-GC, while 11betaHSD2 and 11betaHSD3 only catalyzes the reverse reaction. Recently, rat and human 11betaHSDs were shown to interconvert 7alpha- and 7beta-hydroxy-dehydroepiandrosterone (7alpha- or 7beta-OH-DHEA) with 7-oxo-DHEA. We report that pig kidney microsomes (PKMc) and nuclei (PKN) oxidize 7alpha-OH-DHEA to 7-oxo-DHEA at higher rates with NAD+, than with NADP+. Corticosterone (CS), dehydrocoticosterone (DHC), 11alpha- and 11beta-hydroxyprogesterone, and carbenoxolone completely inhibited these reactions, while 7-oxo-DHEA only inhibited the NAD+-dependent reaction. Conversely, CS oxidation was not inhibited by 7alpha-OH-DHEA or 7-oxo-DHEA. PKMc and PKN did not convert 7-oxo-DHEA to 7-OH-DHEA with either NADPH or NADH. Finally, PKN contained a high affinity, NADPH-dependent 11betaHSD that reduces DHC to CS. The GC effects on interconversion of DHEA metabolites may have clinical significance, since DHEA and its 7-oxidized derivatives have been proposed for treatment of human autoimmune and inflammatory disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 11-beta-Hydroxysteroid Dehydrogenases / antagonists & inhibitors
  • 11-beta-Hydroxysteroid Dehydrogenases / metabolism*
  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Dehydroepiandrosterone / analogs & derivatives
  • Dehydroepiandrosterone / metabolism*
  • Glucocorticoids / metabolism*
  • Kidney / enzymology*
  • Kidney / metabolism
  • Kinetics
  • Microsomes / enzymology*
  • Microsomes / metabolism
  • NAD / metabolism
  • NADP / metabolism
  • Pyridines / metabolism
  • Swine

Substances

  • Anti-Inflammatory Agents
  • Glucocorticoids
  • Pyridines
  • NAD
  • Dehydroepiandrosterone
  • NADP
  • 3-acetoxyandrost-5-ene-7,17-dione
  • 11-beta-Hydroxysteroid Dehydrogenases