Chapter title |
Adenosine Receptors and the Heart: Role in Regulation of Coronary Blood Flow and Cardiac Electrophysiology
|
---|---|
Chapter number | 6 |
Book title |
Adenosine Receptors in Health and Disease
|
Published in |
Handbook of experimental pharmacology, July 2009
|
DOI | 10.1007/978-3-540-89615-9_6 |
Pubmed ID | |
Book ISBNs |
978-3-54-089614-2, 978-3-54-089615-9
|
Authors |
Mustafa SJ, Morrison RR, Teng B, Pelleg A, S. Jamal Mustafa, R. Ray Morrison, Bunyen Teng, Amir Pelleg, S. Jamal Mustafa, R. Ray Morrison, Mustafa, S. Jamal, Morrison, R. Ray, Teng, Bunyen, Pelleg, Amir |
Abstract |
Adenosine is an autacoid that plays a critical role in regulating cardiac function, including heart rate, contractility, and coronary flow. In this chapter, current knowledge of the functions and mechanisms of action of coronary flow regulation and electrophysiology will be discussed. Currently, there are four known adenosine receptor (AR) subtypes, namely A(1), A(2A), A(2B), and A(3). All four subtypes are known to regulate coronary flow. In general, A(2A)AR is the predominant receptor subtype responsible for coronary blood flow regulation, which dilates coronary arteries in both an endothelial-dependent and -independent manner. The roles of other ARs and their mechanisms of action will also be discussed. The increasing popularity of gene-modified models with targeted deletion or overexpression of a single AR subtype has helped to elucidate the roles of each receptor subtype. Combining pharmacologic tools with targeted gene deletion of individual AR subtypes has proven invaluable for discriminating the vascular effects unique to the activation of each AR subtype. Adenosine exerts its cardiac electrophysiologic effects mainly through the activation of A(1)AR. This receptor mediates direct as well as indirect effects of adenosine (i.e., anti-beta-adrenergic effects). In supraventricular tissues (atrial myocytes, sinuatrial node and atriovetricular node), adenosine exerts both direct and indirect effects, while it exerts only indirect effects in the ventricle. Adenosine exerts a negative chronotropic effect by suppressing the automaticity of cardiac pacemakers, and a negative dromotropic effect through inhibition of AV-nodal conduction. These effects of adenosine constitute the rationale for its use as a diagnostic and therapeutic agent. In recent years, efforts have been made to develop A(1)R-selective agonists as drug candidates that do not induce vasodilation, which is considered an undesirable effect in the clinical setting. |
X Demographics
Geographical breakdown
Country | Count | As % |
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Unknown | 1 | 100% |
Demographic breakdown
Type | Count | As % |
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Members of the public | 1 | 100% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Spain | 1 | <1% |
Netherlands | 1 | <1% |
United States | 1 | <1% |
Belgium | 1 | <1% |
Unknown | 124 | 97% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Bachelor | 24 | 19% |
Student > Ph. D. Student | 14 | 11% |
Researcher | 14 | 11% |
Student > Master | 13 | 10% |
Student > Doctoral Student | 10 | 8% |
Other | 25 | 20% |
Unknown | 28 | 22% |
Readers by discipline | Count | As % |
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Pharmacology, Toxicology and Pharmaceutical Science | 18 | 14% |
Biochemistry, Genetics and Molecular Biology | 17 | 13% |
Medicine and Dentistry | 17 | 13% |
Agricultural and Biological Sciences | 15 | 12% |
Chemistry | 9 | 7% |
Other | 19 | 15% |
Unknown | 33 | 26% |