PMID- 7611367
OWN - NLM
STAT- MEDLINE
DCOM- 19950815
LR  - 20171213
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 268
IP  - 6 Pt 1
DP  - 1995 Jun
TI  - NAD-dependent 11 beta-hydroxysteroid dehydrogenase in cultured human colonic 
      epithelial cells.
PG  - C1467-73
AB  - The inactivation of physiological glucocorticoids by 11 beta-hydroxysteroid 
      dehydrogenase (11 beta-HSD) confers mineralocorticoid specificity to certain 
      aldosterone target tissues. However, 11 beta-HSD activity in a human 
      mineralocorticoid-responsive tissue has never been characterized. The present 
      studies describe the features of 11 beta-HSD in the cultured human colonic 
      epithelial cell line, T84. The 11 beta-HSD activity of T84 cells resided in the 
      microsomal fraction and showed a marked preference for NAD rather than NADP as 
      cofactor. NAD or NADP (200 microM) increased the conversion of corticosterone to 
      11-dehydrocorticosterone by 24.1 +/- 2.1 and 0.5 +/- 0.7 pmol.mg protein-1.20 
      min-1, respectively, indicating a > 40-fold preference for NAD vs. NADP. The 
      Michaelis constant values for corticosterone and cortisol were 11.3 +/- 1.5 and 
      79.8 +/- 10 nM, respectively. The T84 11 beta-HSD was inhibited by 
      11-dehydrocorticosterone in a noncompetitive fashion [inhibition constant (Ki) = 
      180 +/- 9.6 nM] and by carbenoxolone in a competitive fashion (Ki = 17.4 +/- 1.3 
      nM). The expression of mineralocorticoid receptors in these cells was 
      demonstrated by reverse transcriptase-polymerase chain reaction of mRNA isolated 
      from T84 cells and by [3H]aldosterone binding studies. The coexpression of this 
      NAD-dependent isoform of 11 beta-HSD and mineralocorticoid receptors is 
      consistent with the view that the NAD-dependent isoform is responsible for the 
      specificity of mineralocorticoid responses.
FAU - Reeves, W B
AU  - Reeves WB
AD  - Division of Nephrology, University of Arkansas College of Medicine, Little Rock 
      72205, USA.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Am J Physiol
JT  - The American journal of physiology
JID - 0370511
RN  - 0 (RNA, Messenger)
RN  - 0 (Receptors, Mineralocorticoid)
RN  - 0U46U6E8UK (NAD)
RN  - 4964P6T9RB (Aldosterone)
RN  - 53-59-8 (NADP)
RN  - EC 1.1.- (Hydroxysteroid Dehydrogenases)
RN  - EC 1.1.1.146 (11-beta-Hydroxysteroid Dehydrogenases)
RN  - FO4V44A3G3 (11-dehydrocorticosterone)
RN  - MM6384NG73 (Carbenoxolone)
RN  - W980KJ009P (Corticosterone)
SB  - IM
MH  - 11-beta-Hydroxysteroid Dehydrogenases
MH  - Adenocarcinoma
MH  - Aldosterone/metabolism
MH  - Carbenoxolone/pharmacology
MH  - Cell Line
MH  - Colonic Neoplasms
MH  - Corticosterone/analogs & derivatives/pharmacology
MH  - Epithelium/enzymology
MH  - Gene Expression
MH  - Humans
MH  - Hydroxysteroid Dehydrogenases/*metabolism
MH  - Kinetics
MH  - NAD/metabolism
MH  - NADP/metabolism
MH  - RNA, Messenger/analysis/biosynthesis
MH  - Receptors, Mineralocorticoid/biosynthesis
MH  - Tumor Cells, Cultured
EDAT- 1995/06/01 00:00
MHDA- 1995/06/01 00:01
CRDT- 1995/06/01 00:00
PHST- 1995/06/01 00:00 [pubmed]
PHST- 1995/06/01 00:01 [medline]
PHST- 1995/06/01 00:00 [entrez]
AID - 10.1152/ajpcell.1995.268.6.C1467 [doi]
PST - ppublish
SO  - Am J Physiol. 1995 Jun;268(6 Pt 1):C1467-73. doi: 
      10.1152/ajpcell.1995.268.6.C1467.