|
rdf:type |
|
|
lifeskim:mentions |
|
|
pubmed:issue |
13
|
|
pubmed:dateCreated |
1998-10-15
|
|
pubmed:abstractText |
Previous work indicated that hyperstimulation of muscarinic receptors brings about profound changes not only in the density of the muscarinic receptors, but also of the beta-adrenoceptors in rat heart atria in vivo. We have now investigated whether a similar receptor cross-regulation occurs in cardiomyocytes in vitro. Cardiomyocytes from 3-4 day old rats were exposed to chemical agents on days 5-6 in culture. Densities of muscarinic and beta-adrenergic receptors were measured according to the binding of N-[3H]methylscopolamine and [ H]CGP 12177, respectively, to cell surface membranes and cell homogenates. Exposure of cells to the muscarinic agonist carbachol (1 mmol/l) brought about a profound decrease in the number of muscarinic receptors. The number of beta-adrenoceptors displayed biphasic changes, being augmented after 24 h (by 20-45% on the cell surface and by 29% in the homogenate) and diminished after 48 h and 72 h (after 48 h, decrease by 44-75% on the cell surface and by 36% in the homogenate). These effects of carbachol were not prevented by dimethylaminopropyl-bis-indolylmaleimide, the inhibitor of protein kinase C. Exposure of cells to the beta-adrenoceptor agonist isoprenaline (0.1 mmol/l) strongly diminished the number of beta-adrenoceptors on the cell surface and in the homogenate. The density of muscarinic receptors on the cell surface was diminished by 24-43% after 24 h exposure to isoprenaline and unchanged after 48 h, whereas the concentration of muscarinic receptors in the homogenate was unchanged after 24 h and increased by 20% after 48 h. The isoprenaline-induced decrease in the density of cell surface muscarinic receptors could not be simulated by forskolin and was not abolished by the protein kinase A inhibitors Rp-cAMPS and HA-1004. Dibutyryl cyclic AMP diminished the density of cell surface muscarinic receptors more than that of the beta-adrenergic receptors. Our data reveal a novel phenomenon of a biphasic change (an increase followed by a loss) in the density of beta-adrenoceptors during exposure of cardiocytes to carbachol. Activation of beta-adrenoceptors brings about less conspicuous changes in the density of muscarinic receptors. The observed phenomena of receptor cross-regulation cannot be explained by simple activations of protein kinases A and C.
|
|
pubmed:grant |
|
|
pubmed:language |
eng
|
|
pubmed:journal |
|
|
pubmed:citationSubset |
IM
|
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic beta-Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic beta-Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Bucladesine,
http://linkedlifedata.com/resource/pubmed/chemical/CGP 12177,
http://linkedlifedata.com/resource/pubmed/chemical/Carbachol,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/Forskolin,
http://linkedlifedata.com/resource/pubmed/chemical/Indoles,
http://linkedlifedata.com/resource/pubmed/chemical/Isoproterenol,
http://linkedlifedata.com/resource/pubmed/chemical/Isoquinolines,
http://linkedlifedata.com/resource/pubmed/chemical/Maleimides,
http://linkedlifedata.com/resource/pubmed/chemical/Muscarinic Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/N-(2-guanidinoethyl)-5-isoquinolines...,
http://linkedlifedata.com/resource/pubmed/chemical/N-Methylscopolamine,
http://linkedlifedata.com/resource/pubmed/chemical/Propanolamines,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase C,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Adrenergic, alpha,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Muscarinic,
http://linkedlifedata.com/resource/pubmed/chemical/Sulfonamides,
http://linkedlifedata.com/resource/pubmed/chemical/Thionucleotides,
http://linkedlifedata.com/resource/pubmed/chemical/Tritium,
http://linkedlifedata.com/resource/pubmed/chemical/adenosine-3',5'-cyclic...,
http://linkedlifedata.com/resource/pubmed/chemical/bisindolylmaleimide I
|
|
pubmed:status |
MEDLINE
|
|
pubmed:issn |
0024-3205
|
|
pubmed:author |
|
|
pubmed:issnType |
Print
|
|
pubmed:volume |
63
|
|
pubmed:owner |
NLM
|
|
pubmed:authorsComplete |
Y
|
|
pubmed:pagination |
1169-82
|
|
pubmed:dateRevised |
2007-11-15
|
|
pubmed:meshHeading |
pubmed-meshheading:9763212-Adrenergic beta-Agonists,
pubmed-meshheading:9763212-Adrenergic beta-Antagonists,
pubmed-meshheading:9763212-Animals,
pubmed-meshheading:9763212-Binding, Competitive,
pubmed-meshheading:9763212-Binding Sites,
pubmed-meshheading:9763212-Bucladesine,
pubmed-meshheading:9763212-Carbachol,
pubmed-meshheading:9763212-Cells, Cultured,
pubmed-meshheading:9763212-Cyclic AMP,
pubmed-meshheading:9763212-Enzyme Inhibitors,
pubmed-meshheading:9763212-Female,
pubmed-meshheading:9763212-Forskolin,
pubmed-meshheading:9763212-Indoles,
pubmed-meshheading:9763212-Isoproterenol,
pubmed-meshheading:9763212-Isoquinolines,
pubmed-meshheading:9763212-Kinetics,
pubmed-meshheading:9763212-Male,
pubmed-meshheading:9763212-Maleimides,
pubmed-meshheading:9763212-Muscarinic Agonists,
pubmed-meshheading:9763212-Myocardium,
pubmed-meshheading:9763212-N-Methylscopolamine,
pubmed-meshheading:9763212-Propanolamines,
pubmed-meshheading:9763212-Protein Kinase C,
pubmed-meshheading:9763212-Radioligand Assay,
pubmed-meshheading:9763212-Rats,
pubmed-meshheading:9763212-Rats, Wistar,
pubmed-meshheading:9763212-Receptors, Adrenergic, alpha,
pubmed-meshheading:9763212-Receptors, Muscarinic,
pubmed-meshheading:9763212-Sulfonamides,
pubmed-meshheading:9763212-Thionucleotides,
pubmed-meshheading:9763212-Tritium
|
|
pubmed:year |
1998
|
|
pubmed:articleTitle |
Heterologous regulation of muscarinic and beta-adrenergic receptors in rat cardiomyocytes in culture.
|
|
pubmed:affiliation |
Institute of Physiology, Academy of Sciences of the Czech Republic, Prague.
|
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|
