Isoproterenol stimulates rapid extrusion of sodium from isolated smooth muscle cells
dc.contributor.author | Moore, Edwin D. W. | |
dc.contributor.author | Fay, Fredric S. | |
dc.date | 2022-08-11T08:09:36.000 | |
dc.date.accessioned | 2022-08-23T16:37:18Z | |
dc.date.available | 2022-08-23T16:37:18Z | |
dc.date.issued | 1993-09-01 | |
dc.date.submitted | 2009-04-02 | |
dc.identifier.citation | <p>Proc Natl Acad Sci U S A. 1993 Sep 1;90(17):8058-62.</p> | |
dc.identifier.issn | 0027-8424 (Print) | |
dc.identifier.pmid | 8367463 | |
dc.identifier.uri | http://hdl.handle.net/20.500.14038/38986 | |
dc.description.abstract | beta-Agonists cause an inhibition of contractility and a transient stimulation of Na+/K+ pumping in smooth muscle cells of the stomach from the toad Bufo marinus. To determine if the stimulation of Na+/K+ pumping causes changes in intracellular [Na+] ([Na+]i) that might link Na+ pump stimulation to decrease Ca2+ availability for contraction, [Na+]i was measured in these cells with SBFI, a Na(+)-sensitive fluorescent indicator. Basal [Na+]i was 12.8 +/- 4.2 mM (n = 32) and was uniform throughout the cell. In response to isoproterenol, [Na+]i decreased an average of 7.1 +/- 1.1 mM in 3 sec. Since this decrease in [Na+]i could be completely blocked by inhibition of the Na+ pump, or by blockade of the beta-receptor, [Na+]i reduction is the result of occupation of the beta-receptor by isoproterenol and subsequent stimulation of the Na+ pump. 8-Bromoadenosine 3',5'-cyclic monophosphate and forskolin mimicked the effect of isoproterenol, indicating that the sequence of events linking beta-receptor occupation to Na+ pump stimulation most likely includes activation of adenylate cyclase, production of cAMP, and stimulation of cAMP-dependent protein kinase. The decrease in [Na+]i is sufficiently large and fast that it is expected to stimulate turnover of the Na+/Ca2+ exchanger in the Ca2+ extrusion mode, thereby accounting for the observed linkage between stimulation of the Na+/K+ pump and inhibition of contractility in response to beta-adrenergic agonists. | |
dc.language.iso | en_US | |
dc.relation | <p><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&list_uids=8367463&dopt=Abstract">Link to Article in PubMed</a></p> | |
dc.relation.url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC47287/ | |
dc.subject | 8-Bromo Cyclic Adenosine Monophosphate | |
dc.subject | Animals | |
dc.subject | Benzofurans | |
dc.subject | Bufo marinus | |
dc.subject | Carbachol | |
dc.subject | Ethers, Cyclic | |
dc.subject | Fluorescent Dyes | |
dc.subject | Forskolin | |
dc.subject | Isoproterenol | |
dc.subject | Kinetics | |
dc.subject | Microscopy, Fluorescence | |
dc.subject | Muscle, Smooth | |
dc.subject | Ouabain | |
dc.subject | Pindolol | |
dc.subject | Potassium | |
dc.subject | Sodium | |
dc.subject | Stomach | |
dc.subject | Time Factors | |
dc.subject | Life Sciences | |
dc.subject | Medicine and Health Sciences | |
dc.title | Isoproterenol stimulates rapid extrusion of sodium from isolated smooth muscle cells | |
dc.type | Journal Article | |
dc.source.journaltitle | Proceedings of the National Academy of Sciences of the United States of America | |
dc.source.volume | 90 | |
dc.source.issue | 17 | |
dc.identifier.legacycoverpage | https://escholarship.umassmed.edu/oapubs/1813 | |
dc.identifier.contextkey | 808579 | |
html.description.abstract | <p>beta-Agonists cause an inhibition of contractility and a transient stimulation of Na+/K+ pumping in smooth muscle cells of the stomach from the toad Bufo marinus. To determine if the stimulation of Na+/K+ pumping causes changes in intracellular [Na+] ([Na+]i) that might link Na+ pump stimulation to decrease Ca2+ availability for contraction, [Na+]i was measured in these cells with SBFI, a Na(+)-sensitive fluorescent indicator. Basal [Na+]i was 12.8 +/- 4.2 mM (n = 32) and was uniform throughout the cell. In response to isoproterenol, [Na+]i decreased an average of 7.1 +/- 1.1 mM in 3 sec. Since this decrease in [Na+]i could be completely blocked by inhibition of the Na+ pump, or by blockade of the beta-receptor, [Na+]i reduction is the result of occupation of the beta-receptor by isoproterenol and subsequent stimulation of the Na+ pump. 8-Bromoadenosine 3',5'-cyclic monophosphate and forskolin mimicked the effect of isoproterenol, indicating that the sequence of events linking beta-receptor occupation to Na+ pump stimulation most likely includes activation of adenylate cyclase, production of cAMP, and stimulation of cAMP-dependent protein kinase. The decrease in [Na+]i is sufficiently large and fast that it is expected to stimulate turnover of the Na+/Ca2+ exchanger in the Ca2+ extrusion mode, thereby accounting for the observed linkage between stimulation of the Na+/K+ pump and inhibition of contractility in response to beta-adrenergic agonists.</p> | |
dc.identifier.submissionpath | oapubs/1813 | |
dc.contributor.department | Department of Physiology | |
dc.source.pages | 8058-62 |