Linked Life Data

11481606

Source:http://linkedlifedata.com/resource/pubmed/id/11481606

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-8-1
pubmed:abstractText
Regulation of bile acid synthesis, a key determinant of cholesterol homeostasis, is still incompletely understood. To elucidate the feedback control exerted on bile acid biosynthesis in humans with obstructive cholestasis, 16 patients with bile duct obstruction were studied. In vivo 7alpha-hydroxylation, reflecting bile acid synthesis, was assayed in 13 of them by tritium release analysis. Serum 27-hydroxycholesterol was determined by gas chromatography-mass spectrometry. In a subgroup, hepatic cholesterol 7alpha-hydroxylase mRNA was assayed by real-time polymerase chain reaction (PCR), enzyme activity was determined by isotope incorporation, and microsomal cholesterol content was assayed by gas chromatography-mass spectrometry. Age-matched control subjects were studied in parallel. Hydroxylation rates were lower in cholestatic patients (108 +/- 33 mg of cholesterol per day, mean +/- SEM; controls: 297 +/- 40 mg/d; P <.01). The reduction was proportional to the severity of cholestasis, and synthetic rates were normalized in 4 subjects restudied after resolution of biliary obstruction. Consistent findings were obtained by analysis of serum 7alpha-hydroxycholesterol levels. On the other hand, hepatic cholesterol 7alpha-hydroxylase mRNA, microsomal enzyme activity, and cholesterol content tended to be increased in cholestasis. Finally, serum 27-hydroxycholesterol levels were slightly reduced in cholestatic subjects and were not related with the severity of the disease. Suppression of in vivo bile acid synthesis with no corresponding reduction in tissue 7alpha-hydroxylase expression and activity is consistent with nontranscriptional, posttranslational levels of regulation; these may play a role in the feedback control of bile acid synthesis in particular conditions. Alteration of the alternate biosynthetic pathway seems unlikely according to the present data.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0270-9139
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
234-42
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Suppression of bile acid synthesis, but not of hepatic cholesterol 7alpha-hydroxylase expression, by obstructive cholestasis in humans.
pubmed:affiliation
Dipartimento di Medicina Interna, Università degli Studi di Modena e Reggio Emilia, Modena, Italy. bertolotti.marco@unimo.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't