Linked Life Data

2843407

Source:http://linkedlifedata.com/resource/pubmed/id/2843407

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1988-10-27
pubmed:abstractText
The mechanisms by which insulin and catecholamines affect low-density lipoprotein (LDL)-receptor activity were studied in freshly isolated human mononuclear leukocytes. Incubation of cells for up to 24 h in a lipid-free medium resulted in an increase in the specific binding, accumulation, and degradation of 125I-labeled LDL. Insulin stimulated the ability of the cells to bind, accumulate, and degrade the lipoprotein with high affinity, which may be caused by an increase in the LDL-receptor number without altering binding affinity. (-)-Epinephrine inhibited the specific binding, accumulation, and degradation of 125I-LDL. This effect appears to be mediated by a decrease in the number of LDL receptors and not by a change in the binding affinity. (-)-Norepinephrine, the unspecific beta-adrenergic agonist (-)-isoproterenol, and the beta 2-specific agonist terbutaline mimicked the effect of epinephrine on LDL-receptor activity. Catecholamines and beta-adrenergic agonists yielded sigmoidal log-concentration effect curves. The action of epinephrine was attenuated by the beta-antagonist (dl)-propranolol. These results demonstrate that insulin stimulates and catecholamines suppress the specific binding, accumulation, and degradation of 125I-LDL in human mononuclear leukocytes. The catecholamine action appears to be mediated by beta 2-adrenergic receptors. A suppression of LDL-receptor activity resulting from deficiency of insulin and elevated plasma catecholamine concentrations in uncontrolled insulin-dependent diabetic patients may contribute to the increased levels of LDL cholesterol observed in these patients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1386-91
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Opposite effects of insulin and catecholamines on LDL-receptor activity in human mononuclear leukocytes.
pubmed:affiliation
Medizinische Kernklinik und Poliklinik, Universitäts-Krankenhaus Eppendorf, Hamburg, Federal Republic of Germany.
pubmed:publicationType
Journal Article, In Vitro