Adenosine inhibition of beta-adrenergic induced responses in aged hearts
dc.contributor.author | Dobson, James G. Jr. | |
dc.contributor.author | Fenton, Richard A. | |
dc.date | 2022-08-11T08:10:16.000 | |
dc.date.accessioned | 2022-08-23T17:02:00Z | |
dc.date.available | 2022-08-23T17:02:00Z | |
dc.date.issued | 1993-08-01 | |
dc.date.submitted | 2008-06-09 | |
dc.identifier.citation | Am J Physiol. 1993 Aug;265(2 Pt 2):H494-503. | |
dc.identifier.issn | 0002-9513 (Print) | |
dc.identifier.pmid | 8103639 | |
dc.identifier.uri | http://hdl.handle.net/20.500.14038/44128 | |
dc.description.abstract | Because adenosine has an antiadrenergic action in the heart, young (3-4 mo) and aged (18-20 mo) adult Sprague-Dawley and Fischer 344 rat hearts were perfused to determine whether interstitial adenosine plays a role in the reduced metabolic and mechanical responsiveness of the aged heart to beta-adrenergic stimulation. Interstitial adenosine was approximately twofold greater in aged hearts compared with young adult hearts, and 10(-8) M isoproterenol (ISO) further increased these levels. ISO increased myocardial adenosine 3',5'-cyclic monophosphate content, glycogen phosphorylase activity, and cardiac contractility by 83, 150, and 130%, respectively, in young hearts but only increased these variables by 45, 74, and 61%, respectively, in aged hearts. Sulfophenyl-theophylline prevented the reduced ISO-induced responsiveness of the above variables in aged hearts. Exogenously administered adenosine deaminase eliminated the reduced ISO-induced contractile responsiveness in aged hearts. The apparent activities of 5'-nucleotidase and adenosine deaminase were not significantly different in ventricular samples from young and aged hearts. These results suggest that the elevated interstitial level of adenosine exerts a greater antiadrenergic effect in the aged heart, rendering it less responsive to beta-adrenergic stimulation. The increased interstitial level of adenosine in the aged heart does not appear to be due to a difference in the activities of either 5'-nucleotidase or adenosine deaminase. | |
dc.language.iso | en_US | |
dc.relation | <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8103639&dopt=Abstract ">Link to article in PubMed</a> | |
dc.relation.url | http://ajpheart.physiology.org/content/265/2/H494.long | |
dc.subject | 5'-Nucleotidase | |
dc.subject | Adenosine | |
dc.subject | Adenosine Deaminase | |
dc.subject | Adrenergic beta-Antagonists | |
dc.subject | Aging | |
dc.subject | Animals | |
dc.subject | Coronary Vessels | |
dc.subject | Cyclic AMP | |
dc.subject | Extracellular Space | |
dc.subject | Heart | |
dc.subject | Inosine | |
dc.subject | Male | |
dc.subject | Myocardial Contraction | |
dc.subject | Myocardium | |
dc.subject | Oxygen Consumption | |
dc.subject | Phosphorylases | |
dc.subject | Rats | |
dc.subject | Rats, Inbred F344 | |
dc.subject | Rats, Sprague-Dawley | |
dc.subject | Cardiovascular Diseases | |
dc.subject | Physiology | |
dc.title | Adenosine inhibition of beta-adrenergic induced responses in aged hearts | |
dc.type | Journal Article | |
dc.source.journaltitle | The American journal of physiology | |
dc.source.volume | 265 | |
dc.source.issue | 2 Pt 2 | |
dc.identifier.legacycoverpage | https://escholarship.umassmed.edu/physio_pp/10 | |
dc.identifier.contextkey | 521862 | |
html.description.abstract | <p>Because adenosine has an antiadrenergic action in the heart, young (3-4 mo) and aged (18-20 mo) adult Sprague-Dawley and Fischer 344 rat hearts were perfused to determine whether interstitial adenosine plays a role in the reduced metabolic and mechanical responsiveness of the aged heart to beta-adrenergic stimulation. Interstitial adenosine was approximately twofold greater in aged hearts compared with young adult hearts, and 10(-8) M isoproterenol (ISO) further increased these levels. ISO increased myocardial adenosine 3',5'-cyclic monophosphate content, glycogen phosphorylase activity, and cardiac contractility by 83, 150, and 130%, respectively, in young hearts but only increased these variables by 45, 74, and 61%, respectively, in aged hearts. Sulfophenyl-theophylline prevented the reduced ISO-induced responsiveness of the above variables in aged hearts. Exogenously administered adenosine deaminase eliminated the reduced ISO-induced contractile responsiveness in aged hearts. The apparent activities of 5'-nucleotidase and adenosine deaminase were not significantly different in ventricular samples from young and aged hearts. These results suggest that the elevated interstitial level of adenosine exerts a greater antiadrenergic effect in the aged heart, rendering it less responsive to beta-adrenergic stimulation. The increased interstitial level of adenosine in the aged heart does not appear to be due to a difference in the activities of either 5'-nucleotidase or adenosine deaminase.</p> | |
dc.identifier.submissionpath | physio_pp/10 | |
dc.contributor.department | Department of Physiology | |
dc.source.pages | H494-503 |