Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1982-1-28
pubmed:abstractText
As a part of the process of agonist-induced desensitization, 1321N1 human astrocytoma cells lose up to 95% of their beta-adrenergic receptors, as detected by 125I-hydroxybenzylpindolol (125IHYP) binding, after 12-24 h of exposure to isoproterenol. In preconfluent cultures the loss of beta-receptors is completely reversible upon removal of isoproterenol, with receptor levels reaching 100% of control levels within 48-72 h. Addition of cycloheximide (5 micrograms/ml) upon removal of agonist does not prevent the recovery of receptors. After an initial 4-h lag, receptors accumulate in the presence of cycloheximide until the same receptor level is reached that was present at the onset of desensitization. Confluent cultures, which have a reduced number of receptors per cell, recover beta-receptors to only 60 to 70% of control levels following removal of isoproterenol. In addition, cycloheximide blocks the recovery of receptors in these cultures. The effects of cycloheximide on the accumulation of receptors during cell growth suggest that receptors are stable in preconfluent cultures and that turnover only occurs later when cultures are confluent. The data also indicate that long term exposure of cells to catecholamine results in a form of the beta-adrenergic receptor that is undetectable by 125IHYP binding but, nonetheless, retains its primary amino acid structure. The undetectable receptors appear to be retained until agonist is removed, whereupon they become detectable by 125IHYP binding with a t1/2 of about 36 h in the presence of cycloheximide.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
256
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12281-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Recovery of beta-adrenergic receptors following long term exposure of astrocytoma cells to catecholamine. Role of protein synthesis.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't