Linked Life Data

8074686

Source:http://linkedlifedata.com/resource/pubmed/id/8074686

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-9-29
pubmed:abstractText
There is some indirect evidence that the pineal hormone melatonin can suppress plasma levels of cholesterol in hypercholesterolemic rats. We have examined the effects of the hormone on cellular cholesterol metabolism in freshly isolated human mononuclear leukocytes. Incubation of cells for up to 20 h in a lipid-free medium resulted in an increase in the rate of cholesterol synthesis from [14C]acetate and the high affinity accumulation and degradation of [125I]labeled low density lipoprotein (LDL). Addition of melatonin in increasing concentrations to the incubation medium at zero time inhibited cholesterol synthesis and the specific accumulation and degradation of [125I]labeled LDL; at a concentration of 100 microM, the inhibitions were 38%, 42%, and 48%, respectively. Similar results were obtained using [14C]mevalonate as precursor. Fatty acid synthesis was not altered under these conditions. In contrast to cholesterol, the synthesis of the first cyclic compound lanosterol was not affected by the pineal hormone. These results implicate that melatonin inhibits this pathway between lanosterol and cholesterol. The action of melatonin on LDL receptor activity appeared to be mediated by a decrease in the number of LDL receptors and not by a change in binding affinity. Pharmacological characterization of the potential melatonin receptor site using several analogs like tryptamine, 5-hydroxytryptamine,N-acetyl-5-hydroxytryptamine, 5-methoxytryptamine, and 6-chloromelatonin indicated that the 5-methoxy group is indispensible for the hormone action on cholesterol synthesis. The data provide evidence that melatonin can modulate cholesterol metabolism in human cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/5-Methoxytryptamine, http://linkedlifedata.com/resource/pubmed/chemical/6-chloromelatonin, http://linkedlifedata.com/resource/pubmed/chemical/Acetates, http://linkedlifedata.com/resource/pubmed/chemical/Carbon Radioisotopes, http://linkedlifedata.com/resource/pubmed/chemical/Cholesterol, http://linkedlifedata.com/resource/pubmed/chemical/Iodine Radioisotopes, http://linkedlifedata.com/resource/pubmed/chemical/Lipoproteins, LDL, http://linkedlifedata.com/resource/pubmed/chemical/Melatonin, http://linkedlifedata.com/resource/pubmed/chemical/Mevalonic Acid, http://linkedlifedata.com/resource/pubmed/chemical/N-acetylserotonin, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, LDL, http://linkedlifedata.com/resource/pubmed/chemical/Serotonin, http://linkedlifedata.com/resource/pubmed/chemical/Tryptamines, http://linkedlifedata.com/resource/pubmed/chemical/tryptamine
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
203
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
416-21
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Melatonin inhibits LDL receptor activity and cholesterol synthesis in freshly isolated human mononuclear leukocytes.
pubmed:affiliation
Klinik II und Poliklinik für Innere Medizin, Universität zu Köln, Germany.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't