Linked Life Data

3553188

Source:http://linkedlifedata.com/resource/pubmed/id/3553188

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1987-6-5
pubmed:abstractText
The mechanism responsible for the stimulation of secretion of lipoprotein lipase by heparin in cultured cells was studied with avian adipocytes in culture. Immunoprecipitation followed by electrophoresis and fluorography were used to isolate and quantitate the radiolabeled enzyme, whereas total lipoprotein lipase was quantitated by radioimmunoassay. Rates of synthesis of lipoprotein lipase were not different for control or heparin treatments as judged by incorporation of L-[35S]methionine counts into lipoprotein lipase during a 20-min pulse. This observation was corroborated in pulse-chase experiments where the calculation of total lipoprotein lipase synthesis, based on the rate of change in enzyme-specific activity during the chase, showed no difference between control (8.13 +/- 3.1) and heparin treatments (9.1 +/- 5.3 ng/h/60-mm dish). Secretion rates of enzyme were calculated from measurements of the radioactivity of the secreted enzyme and the cellular enzyme-specific activity. Degradation rates were calculated by difference between synthesis and secretion rates of enzyme. In control cells 76% of the synthesized enzyme was degraded. Addition of heparin to the culture medium reduced the degradation rate to 21% of the synthetic rate. The presence of heparin in cell media resulted in a decrease in apparent intracellular retention half-time for secreted enzyme from 160 +/- 44 min to 25 +/- 1 min. The above data demonstrate that the increase in lipoprotein lipase protein secretion, observed upon addition of heparin to cultured adipocytes, is due to a decreased degradation rate with no change in synthetic rate. Finally, newly synthesized lipoprotein lipase in cultured adipocytes is secreted constitutively and there is no evidence that it is stored in an intracellular pool.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
262
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6383-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Heparin decreases the degradation rate of lipoprotein lipase in adipocytes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.