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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1993-2-24
pubmed:abstractText
Brown adipocytes are thermogenic cells which play an important role in energy balance. Their thermogenic activity is due to the presence of a mitochondrial uncoupling protein (UCP). Until recently, it was admitted that in rodents brown adipocytes were mainly located in classical brown adipose tissue (BAT). In the present study, we have investigated the presence of UCP protein or mRNA in white adipose tissue (WAT) of rats. Using polymerase chain reaction or Northern blot hybridization, UCP mRNA was detected in mesenteric, epidydimal, retroperitoneal, inguinal and particularly in periovarian adipose depots. The uncoupling protein was detected by Western blotting in mitochondria from periovarian adipose tissue. When rats were submitted to cold or to treatment with a beta-adrenoceptor agonist, UCP expression was increased in this tissue as in typical brown fat. Moreover, the expression was decreased in obese fa/fa rats compared to lean controls. Morphological studies showed that periovarian adipose tissue of rats kept at 24 degrees C contained cells with numerous typical BAT mitochondria with or without multilocular lipid droplets. Immunocytochemistry confirmed that multilocular cells expressed mitochondrial UCP. Furthermore, the number of brown adipocytes and the density of mitochondrial cristae increased in parallel with exposure to cold. These results demonstrate that adipocytes expressing UCP are present in adipose deposits considered as white fat. They suggest the existence of a continuum in rodents between BAT and WAT, and a great plasticity between adipose tissue phenotypes. The physiological importance of brown adipocytes in WAT and the regulation of UCP expression remain open questions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:volume
103 ( Pt 4)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
931-42
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:1362571-Adipose Tissue, pubmed-meshheading:1362571-Adipose Tissue, Brown, pubmed-meshheading:1362571-Adrenergic beta-Agonists, pubmed-meshheading:1362571-Animals, pubmed-meshheading:1362571-Base Sequence, pubmed-meshheading:1362571-Biological Markers, pubmed-meshheading:1362571-Body Temperature Regulation, pubmed-meshheading:1362571-Carrier Proteins, pubmed-meshheading:1362571-Cold Temperature, pubmed-meshheading:1362571-Ethanolamines, pubmed-meshheading:1362571-Female, pubmed-meshheading:1362571-Ion Channels, pubmed-meshheading:1362571-Male, pubmed-meshheading:1362571-Membrane Proteins, pubmed-meshheading:1362571-Mitochondria, pubmed-meshheading:1362571-Mitochondrial Proteins, pubmed-meshheading:1362571-Molecular Sequence Data, pubmed-meshheading:1362571-Ovary, pubmed-meshheading:1362571-Rats, pubmed-meshheading:1362571-Rats, Wistar, pubmed-meshheading:1362571-Rats, Zucker
pubmed:year
1992
pubmed:articleTitle
Occurrence of brown adipocytes in rat white adipose tissue: molecular and morphological characterization.
pubmed:affiliation
Laboratory of Physiopathology of Nutrition, CNRS URA 307, University of Paris VII, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't