Linked Life Data

8641180

Source:http://linkedlifedata.com/resource/pubmed/id/8641180

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1996-7-18
pubmed:abstractText
The 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta HSD-2) enzyme is thought to confer aldosterone specificity upon mineralocorticoid target tissues by protecting the mineralocorticoid receptor from binding by the more abundant glucocorticoids, corticosterone and cortisol. We have developed a Chinese hamster ovary cell line stably transfected with a plasmid containing the rat 11 beta HSD-2 complementary DNA. This cell line has expressed the enzyme consistently for many generations. The 11 beta HSD-2 was located primarily in the microsomes, but significant amounts also existed in the nuclei and mitochondria. The enzymatic reaction was unidirectional, oxidative, and inhibited by the product, 11-dehydrocorticosterone, with an IC50 of approximately 200 nM. The K(m) for corticosterone was 9.6 +/- 3.1 nM, and that for NAD+ was approximately 8 microM. The enzyme did not convert dexamethasone to 11-dehydrodexamethasone. Tunicamycin, an N-glycosylation inhibitor, had no effect on enzyme activity. 11 alpha-Hydroxyprogesterone (11 alpha OH-P) was an order of magnitude more potent a competitive inhibitor of the 11 beta HSD-2 than was glycyrrhetinic acid (GA) (approximate IC50 = 0.9 vs. 15 nM). 11 beta OH-P, progesterone, and GA were almost equipotent (IC50 = 10 and 6 nM, respectively), and 5 alpha-pregnandione and 5 beta-pregnandione were less potent (IC50 = 100 and 500 nM, respectively) inhibitors of the enzyme. When the inhibitory activities were examined with intact transfected cells, 11 alpha OH-P was more potent than GA (IC50 = 5 and 150 nM, respectively). 11 alpha OH-P was not metabolized by 11 beta HSD-2. We were unable to demonstrate the presence of 11 alpha OH-P in human urine. In conclusion, a cell line stably transfected with the rat 11 beta HSD-2 was created, and the enzyme kinetics, including inhibition, were characterized. 11 alpha OH-P was found to be a potent relatively specific inhibitor of the 11 beta HSD-2 enzyme. Its potential importance is that it is the most specific inhibitor of the 11 beta HSD-2 so far encountered and would aid in the study of the physiological importance of the isoenzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
137
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2308-14
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
11 beta-Hydroxysteroid dehydrogenase type 2 complementary deoxyribonucleic acid stably transfected into Chinese hamster ovary cells: specific inhibition by 11 alpha-hydroxyprogesterone.
pubmed:affiliation
Department of Internal Medicine, University of Missouri, Columbia 65212, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.