Linked Life Data

386092

Source:http://linkedlifedata.com/resource/pubmed/id/386092

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1979-12-18
pubmed:abstractText
Glucocorticoids affect the composition and function of the plasma membrane in a variety of cell types. Cultured rat hepatoma (HTC) cells in tissue culture provide an excellent model system for analysis of such effects. In these cells, dexamethasone rapidly and dramatically inhibits the influx of amino acids sharing the A or alanine-preferring transport system. Inhibition is half-maximal within 2 h, and maximal after 6 h incubation with the hormone. The inhibition is rapidly reversed by insulin, and more slowly by removing the steroid. Microtubules and microfilaments are not apparently involved in this hormonal effect, but continuous protein synthesis is required for the glucocorticoid inhibition of transport. Dexamethasone also decreases the number of microvilli on the surface of HTC cells, increases their adhesiveness to a substratum, and dramatically decreases the production of plasminogen activator, but it does not affect the growth rate or plating efficiency of the cells. Variant cell lines stably resistant to dexamethasone inhibition of plasminogen activator production have been isolated using an agar-fibrin overlay technique to detect protease production by individual colonies of HTC cells. The hormonal resistance to inhibition of protease production is associated witha maintenance of inducibility of other glucocorticoid-regulated functions and therefore is not apparently secondary to abnormal or absent glucocorticoid receptor, but due to a lesion in a later step in hormone action specific for plasminogen activator. Combined genetic and biochemical analysis of such dexamethasone-resistant variants should facilitate study of the hormonal regulation of specific membrane phenotypes and of the role of proteases in this regulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0077-1015
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
561-74
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Glucocorticoids and the plasma membrane.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review