Linked Life Data

3559391

Source:http://linkedlifedata.com/resource/pubmed/id/3559391

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1987-5-6
pubmed:abstractText
7 alpha-Hydroxylation of cholesterol is a stereospecific reaction consisting of the replacement of the 7 alpha-hydrogen with a hydroxyl group. When cholesterol labeled with tritium at the 7 alpha position is administered, the hydroxylation of the substrate will result in the loss of tritium which in turn will label the body water. The rate of tritium enrichment of the body water could thus give a quantitative estimate of the hydroxylation rate. This study describes the validation of the procedure with some 21 studies performed on 15 subjects in different conditions. [7 alpha-3H]cholesterol was administered intravenously in 50 ml of plasma and thereafter blood was sampled at timed intervals for 4 to 5 days. The rate of the hydroxylation of cholesterol was calculated from the time course of the specific activities of plasma cholesterol and body water after tracer administration and was expressed as 7 alpha-hydroxycholesterol formed/24 hr. Calculated values of hydroxylation in three control subjects (493 +/- 206), five patients with hyperlipoproteinemia (539 +/- 168), and seven cirrhotic patients (153 +/- 136) are in good agreement with figures reported for bile acid synthesis determined with other techniques. Cholesterol 7 alpha-hydroxylation rate is reduced in patients with cirrhosis, the impairment being related to the severity of the disease. Cholestyramine administered to one subject for 4 weeks produced a threefold increase of the hydroxylation. Administration of chenodeoxycholic acid resulted in a 50% decrease, whereas that of ursodeoxycholic did not produce consistent changes of the hydroxylation rate. The results support the current view that 7 alpha-hydroxylation of cholesterol is rate-limiting in the synthesis of bile acids.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1278-86
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
In vivo evaluation of cholesterol 7 alpha-hydroxylation in humans: effect of disease and drug treatment.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't