Linked Life Data

6631233

Source:http://linkedlifedata.com/resource/pubmed/id/6631233

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1983-12-17
pubmed:abstractText
The regulation of rabbit intestinal acyl CoA:cholesterol acyltransferase (ACAT) by 25-hydroxycholesterol was studied. 25-Hydroxycholesterol significantly increased jejunal microsomal ACAT activity. The stimulation of ACAT activity by 25-hydroxycholesterol was inversely related to microsomal cholesterol content. In enterocytes, 25-hydroxycholesterol stimulated cholesteryl ester synthesis 6-fold. The esterification of cholesterol, taken up by enterocytes from liposomes or bile salt micelles, was increased by 25-hydroxycholesterol. This, however, did not affect the rate of uptake of cholesterol by the cells. In intestinal cells from rabbits fed cholesterol, the effect of 25-hydroxycholesterol on cholesteryl ester synthesis was 50% of that in cells prepared from animals fed no cholesterol. 25-Hydroxycholesterol stimulated the esterification of newly synthesized cholesterol. As new free cholesterol increased in enterocytes, 25-hydroxycholesterol lost its effect. Despite large amounts of newly synthesized cholesterol, oleic acid incorporation into cholesteryl ester was not increased. We conclude that 25-hydroxycholesterol increases intestinal ACAT activity. The effect of 25-hydroxycholesterol on ACAT is dependent upon the availability of cholesterol to the enzyme. At cholesterol concentrations below saturation, the oxygenated sterol has a stimulatory effect. If ACAT is saturated, 25-hydroxycholesterol has no effect. ACAT catalyzes the esterification of two separate pools of cholesterol within the enterocyte, i.e., newly synthesized cholesterol and membrane cholesterol. 25-Hydroxycholesterol increases the esterification rate of cholesterol in both pools.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1049-59
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Regulation of acyl CoA:cholesterol acyltransferase by 25-hydroxycholesterol in rabbit intestinal microsomes and absorptive cells.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't