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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
3
|
| pubmed:dateCreated |
1990-9-11
|
| pubmed:abstractText |
The binding of the alpha 2-agonist [3H]UK 14304 on Wistar rat adipocyte membranes was separated in two distinct components: one was displaceable by adrenaline or other alpha 2-adrenergic agents and possessed the characteristics of alpha 2-adrenoceptors while the other, non-adrenergic in nature, was only recognized by some imidazoline derivatives [3H]idazoxan binding shared the same characteristics. The non-adrenergic sites labeled by both radioligands are similar to those described for [3H]idazoxan on other tissues such as brain cortex, smooth muscle and kidney. Even though they were about 10-fold more numerous than the true alpha 2-adrenoceptors, the non-adrenergic binding sites were not directly involved in the antilipolytic action of UK 14304 since alpha 2-antagonists devoid of interaction with these sites (yohimbine, phentolamine) totally blocked the UK 14304 effect. However, the existence of such a type of site impairs direct quantification of alpha 2-adrenoceptors in rat adipocytes. The use of [3H]RX 821002 (2-(2-methoxy-1,4-benzodioxan-2yl)imidazoline) allowed an accurate quantification of rat adipocyte alpha 2-adrenoceptors (Bmax = 35 +/- 2 fmol/mg protein, Kd = 2.6 +/- 0.6 nM) since it did not interact with non-adrenergic binding sites and exhibited the highest alpha 2-blocking properties among the various alpha 2-antagonists tested. [3H]RX 821002 binding analysis revealed that alpha 2-adrenoceptors are, on rat adipocytes; (i) less numerous than in other species well known for their alpha 2-adrenergic inhibitory regulation of lipolysis (human, hamster, rabbit); (ii) slightly different in nature from the receptors of these species since they had weaker affinity for clonidine and yohimbine; and however (iii) not of the typical alpha 2-B subtype since the affinity of prazosin was lower than that of oxymetazoline in displacing [3H]RX 821002 or [3H]yohimbine binding.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/2-methoxyidazoxan,
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic alpha-Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic alpha-Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Bucladesine,
http://linkedlifedata.com/resource/pubmed/chemical/Dioxanes,
http://linkedlifedata.com/resource/pubmed/chemical/Forskolin,
http://linkedlifedata.com/resource/pubmed/chemical/Idazoxan,
http://linkedlifedata.com/resource/pubmed/chemical/Phentolamine,
http://linkedlifedata.com/resource/pubmed/chemical/Quinoxalines,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Adrenergic, alpha,
http://linkedlifedata.com/resource/pubmed/chemical/Yohimbine,
http://linkedlifedata.com/resource/pubmed/chemical/brimonidine
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Aug
|
| pubmed:issn |
0006-2952
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
40
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
437-45
|
| pubmed:dateRevised |
2003-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:1974423-Adipose Tissue,
pubmed-meshheading:1974423-Adrenergic alpha-Agonists,
pubmed-meshheading:1974423-Adrenergic alpha-Antagonists,
pubmed-meshheading:1974423-Animals,
pubmed-meshheading:1974423-Binding, Competitive,
pubmed-meshheading:1974423-Binding Sites,
pubmed-meshheading:1974423-Bucladesine,
pubmed-meshheading:1974423-Cell Membrane,
pubmed-meshheading:1974423-Dioxanes,
pubmed-meshheading:1974423-Forskolin,
pubmed-meshheading:1974423-Idazoxan,
pubmed-meshheading:1974423-Kinetics,
pubmed-meshheading:1974423-Lipolysis,
pubmed-meshheading:1974423-Phentolamine,
pubmed-meshheading:1974423-Quinoxalines,
pubmed-meshheading:1974423-Rats,
pubmed-meshheading:1974423-Rats, Inbred Strains,
pubmed-meshheading:1974423-Receptors, Adrenergic, alpha,
pubmed-meshheading:1974423-Yohimbine
|
| pubmed:year |
1990
|
| pubmed:articleTitle |
Non-adrenergic sites for imidazolines are not directly involved in the alpha 2-adrenergic antilipolytic effect of UK 14304 in rat adipocytes.
|
| pubmed:affiliation |
I.N.S.E.R.M. Unité 317, Institut de Physiologie, Université Paul Sabatier, Toulouse, France.
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| pubmed:publicationType |
Journal Article
|