Muscarinic binding sites on bovine pulmonary arterial endothelial cells in culture.
Pharmacology
; 44(6): 324-33, 1992.
Article
en En
| MEDLINE
| ID: mdl-1508962
We have investigated the presence and nature of muscarinic binding sites on membranes from cultured bovine pulmonary arterial endothelial cells (BPAE). BPAE were harvested and subcultured nonenzymatically; experiments were performed 3-5 days postconfluence and between 10 and 25 passage numbers. Utilizing radioligand binding techniques with the muscarinic receptor antagonists [3H]3-quinuclidinyl benzilate ([3H]QNB) and [3H]N-methylscopolamine ([3H]MS) as probes, we identified a small population of atropine-sensitive muscarinic sites (1,800-2,000 sites/cell or 7-8 fmol/mg protein). Muscarinic binding sites on BPAE membranes resembled classical muscarinic receptors in that (a) the binding of 2 nM [3H]QNB was inhibited by muscarinic agonists and antagonists, (b) [3H]QNB binding was 30 times more sensitive to R(-)- than to S(+)-QNB, (c) binding of the muscarinic receptor agonist carbamylcholine involved high and low affinity components, (d) the stable GTP analog, Gpp(NH)p (100 microM) shifted agonist binding curves to the right by a factor of three, and (e) the high affinity binding of the agonist [3H]oxotremorine-M to muscarinic receptors was depressed by Gpp(NH)p. On the other hand, gallamine, which allosterically regulates muscarinic receptor binding in other tissues, did not affect the rates of dissociation of [3H]QNB, [3H]MS or [3H]oxotremorine-M from BPAE binding sites. We concluded that BPAE in culture exhibit muscarinic binding sites which possess many but not all of the properties associated with classical muscarinic receptors.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Parasimpatolíticos
/
Parasimpaticomiméticos
/
Arteria Pulmonar
/
Derivados de Escopolamina
/
Endotelio Vascular
/
Receptores Muscarínicos
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Pharmacology
Año:
1992
Tipo del documento:
Article
Pais de publicación:
Suiza