Linked Life Data

2614251

Source:http://linkedlifedata.com/resource/pubmed/id/2614251

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1990-3-2
pubmed:abstractText
The relationships between cholesterol 7 alpha-hydroxylase activity, pool of free microsomal cholesterol, and degree of substrate saturation of the enzyme were studied in untreated (n = 5), cholesterol-fed (n = 4), and cholestyramine-treated (n = 6) gallstone patients undergoing cholecystectomy. Highly accurate methods based on isotope dilution-mass spectrometry were used for assay of the cholesterol 7 alpha-hydroxylase activity and for determination of the concentration of free cholesterol in the microsomes. The cholesterol-enriched diet increased the cholesterol 7 alpha-hydroxylase activity about twofold. Cholestyramine treatment was associated with a five- to sixfold increase of the cholesterol 7 alpha-hydroxylase activity. The concentration of free microsomal cholesterol remained essentially unchanged. The apparent degree of saturation of the enzyme was calculated to be 85% in the untreated patients, 86% in the cholesterol-fed patients, and 67% in those treated with cholestyramine. A significant negative correlation was obtained between enzyme activity and apparent substrate saturation. It is concluded that the apparent substrate saturation of the cholesterol 7 alpha-hydroxylase in human liver microsomes is high but that availability of cholesterol may limit the enzyme activity to some extent a high bile acid synthesis rates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1477-81
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
On the saturation of the cholesterol 7 alpha-hydroxylase in human liver microsomes.
pubmed:affiliation
Department of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't