Linked Life Data

12441311

Source:http://linkedlifedata.com/resource/pubmed/id/12441311

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2003-1-30
pubmed:abstractText
We have previously reported that chronic leptin administration (2 wk) increases fatty acid (FA) oxidation and triacylglycerol hydrolysis in rodent soleus muscle. Acute stimulation of AMP-activated protein kinase (AMPK) results in a repartitioning of FA toward oxidation and away from esterification in rodent soleus muscle and has recently been shown to be responsible, at least in part, for the acute stimulatory effect of leptin on FA oxidation. Therefore, we hypothesized that the effects of chronic leptin treatment on muscle FA metabolism are mediated in part through an increased expression and/or activation of AMPK and a subsequent phosphorylation of acetyl-CoA carboxylase and a decrease in malonyl-CoA content. Female Sprague-Dawley rats were infused for 2 wk with leptin (0.5 mg x kg(-1) x day(-1)) using subcutaneously implanted mini-osmotic pumps. Control and pair-fed animals received saline-filled implants. Leptin levels were elevated approximately fourfold (P < 0.001) in treated animals, relative to controls. Chronic leptin treatment resulted in an approximately 2- to 3-fold greater protein expression of AMPK catalytic (alpha(2)) and regulatory (beta(2)) units as well as a 1.5- to 2-fold increase in Thr(172) phosphorylation of AMPK in both soleus and white gastrocnemius muscles. The increased expression/phosphorylation of AMPK was not the result of an altered energy status of the muscle. Correspondingly, there was also a 1.5- to 2-fold increase in acetyl-CoA carboxylase (ACC) phosphorylation after leptin treatment in soleus and white gastrocnemius. In spite of the measured increase in ACC phosphorylation after leptin treatment, we were unable to detect a decrease in resting malonyl-CoA content in either muscle. However, taken as a whole, our data support recent evidence in rodent muscle that leptin stimulates FA oxidation through stimulation of AMPK and a subsequent downregulation of ACC activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0193-1849
pubmed:author
pubmed:issnType
Print
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
E648-54
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
AMPK expression and phosphorylation are increased in rodent muscle after chronic leptin treatment.
pubmed:affiliation
Department of Human Biology and Nutritional Sciences, University of Guelph, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't