Linked Life Data

9644096

Source:http://linkedlifedata.com/resource/pubmed/id/9644096

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1998-9-24
pubmed:abstractText
Obesity is associated with an increased incidence of insulin resistance, dyslipoproteinemia, and hypercoagulability. In a more recently established hypothesis of body weight control and regulation of metabolism, the adipocyte secretes leptin and locally expresses TNF-alpha, the latter being responsible for the expression of metabolic cardiovascular risk factors. TNF-a mRNA expression and TNF-alpha protein are greatly increased in adipose tissue from obese animals and humans. Elevated TNF-alpha expression induces insulin resistance by downregulating the tyrosine kinase activity of the insulin receptor and decreasing the expression of GLUT-4 glucose transporters. TNF-alpha also reduces lipoprotein lipase activity in white adipocytes, stimulates hepatic lipolysis, and increases plasminogen activator inhibitor-1 content in adipocytes. Moreover, adipocytes secrete leptin, a molecule with a secondary cytokine structure whose concentrations correlate with the amount of fat tissue. Increased leptin levels downregulate appetite and increase sympathetic activity and thermogenesis in the hypothalamus. Diet-induced weight loss reduces adipose TNF-alpha expression and serum leptin levels and is associated with improved insulin sensitivity and lipid metabolism. Although exercise has also been shown to reduce leptin levels, an influence on TNF-a expression in adipocytes or muscle cells has not yet been demonstrated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1077-5552
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
77-94
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Importance of TNF-alpha and leptin in obesity and insulin resistance: a hypothesis on the impact of physical exercise.
pubmed:affiliation
Dept. of Rehabilitation, Prevention, and Sports Medicine, Freiburg University Hospital, Germany.
pubmed:publicationType
Journal Article, Review