Linked Life Data

3004089

Source:http://linkedlifedata.com/resource/pubmed/id/3004089

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1986-3-4
pubmed:abstractText
In newborn rat adrenal cells in primary culture, the level of activity of the 11 beta/18-steroid hydroxylase system involved in the last step of the corticosteroid biosynthesis is increased by ACTH. A parallel study of 11 beta- and 18-hydroxylation showed the same apparent Km values (64 microM) for both hydroxylations. The Vmax values differed: 11.5 micrograms/10(6) cells/h for corticosterone and 6.9 micrograms/10(6) cells/h for 18-hydroxyDOC. A dose response study of the ACTH effect, measured by the bioconversion of deoxycorticosterone to corticosterone and 18-hydroxyDOC, showed maximum hydroxylation with a dose of 2.2 mU of ACTH/ml. Addition of ACTH after several weeks in culture produced a smaller increase in 11 beta/18-hydroxylation. Removal of ACTH after several weeks of treatment produced an immediate decrease in corticosteroid production; readdition of ACTH produced an increase to the previous level in the case of the 22 mU/ml dose, but not in the case of the 2.2 mU/ml dose. The use of actinomycin D demonstrated that ACTH affects mainly the biosynthesis of protein which must be renewed approximately every 24 h. Finally, the effect of pretreatment or co-treatment with various concentrations of the end products of the reaction showed no inhibition or destruction of the 11 beta/18-hydroxylating enzyme system. Therefore, the regulation of the 11 beta/18-steroid hydroxylase system in these cell cultures seems to be accomplished through the induction by ACTH of the transcription involved in the biosynthesis of cytochrome P450(11) beta and the amount of available precursor furnished by endogenous steroidogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0001-5598
pubmed:author
pubmed:issnType
Print
pubmed:volume
111
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
106-15
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Regulation of 11 beta/18-steroid hydroxylation in newborn rat adrenal cells in primary culture.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't