Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1987-2-27
pubmed:abstractText
In vitro incubation of mononuclear leukocytes (MNL) with catecholamines desensitizes beta adrenergic receptors, meaning isoproterenol-stimulated cyclic AMP accumulation decreases. This desensitization is accompanied by two patterns of receptor changes: first, reduction of surface receptors (defined as binding of [3H]dihydroalprenolol inhibited by 1 microM CGP 12177 [4-3-tertiarybutylamino-2-hydroxypropoxy)-benzimidazole- 2-on-hydrochloride]) without any change in the total number of [3H] dihydroalprenolol binding sites inhibited by 1 microM propranolol (receptor redistribution); then reduction of the total number of receptors (receptor down-regulation). In the present study we investigated receptor redistribution and down-regulation under physiological conditions by raising endogenous catecholamines in the rat by stress. In young rats a single immobilization stress induced MNL beta adrenergic receptor redistribution: the number of surface receptors was reduced by about 50% but the total number remained the same. Receptor redistribution was prevented completely in rats pretreated with beta-blocking nadolol. Repeated stress down-regulated the MNL beta adrenergic receptors as shown by a reduction in the total number of sites. We also investigated the regulation of beta adrenergic receptors in three age-groups. After 60 min of immobilization stress the number of MNL surface receptors was reduced in young (4-month-old) rats but not in mature (12-month-old) or aged (26-month-old) rats. Using an alternative stress procedure, after single or repeated open-field sessions, we found receptor redistribution and down-regulation, respectively, in young rats. None of these adaptive receptor response was observed in 26-month-old rats.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
240
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
228-33
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Regulation of beta adrenergic receptors on rat mononuclear leukocytes by stress: receptor redistribution and down-regulation are altered with aging.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't