A biphasic response to adenosine in the coronary vasculature of the K(+)-arrested perfused rat heart
| Autor: | John P. Headrick, Glenn Harrison, Lindsay R. Jordan, Roger J. Willis, Fiona Harden |
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| Rok vydání: | 1996 |
| Předmět: |
Male
medicine.medical_specialty Adenosine Muscle Relaxation Vasodilator Agents Adenosine A2A receptor Vasodilation Adenosine-5'-(N-ethylcarboxamide) In Vitro Techniques chemistry.chemical_compound Adenosine Triphosphate Theophylline Internal medicine medicine Purinergic P1 Receptor Agonists Animals Rats Wistar Pharmacology business.industry Heart Adenosine A3 receptor Adenosine receptor Coronary Vessels Rats Perfusion Endocrinology Muscle relaxation chemistry Heart Arrest Induced Potassium business Adenosine triphosphate Adenosine A2B receptor medicine.drug |
| Zdroj: | European journal of pharmacology. 307(1) |
| ISSN: | 0014-2999 |
| Popis: | Biphasic vasodilatory responses to adenosine and 5'-N-ethylcarboxamidoadenosine (NECA) were observed in the coronary vasculature of K(+)-arrested perfused rat hearts. Dose-response data for both agonists were best represented by two-site models. For adenosine, two sites with negative log ED50 (pED50) values of 8.1 +/- 0.1 (mean +/- S.E.M) and 5.2 +/- 0.1 were obtained, mediating 31 +/- 2% and 69 +/- 2% of the total response. In the presence of 8-phenyltheophylline, the vasodilatory response to adenosine remained best fitted to a two-site model with pED50 values of 7.0 +/- 0.2 and 5.4 +/- 0.2. The relative contribution of each site to the total response remained unchanged. For NECA, pED50 values of 9.6 +/- 0.1 and 6.8 +/- 0.2 were obtained, representing 48 +/- 3% and 52 +/- 3% of the sites, respectively. In contrast, ATP produced a monophasic response with a pED50 value of 8.8 +/- 0.1. These results provide evidence of adenosine receptor and response heterogeneity in the in situ coronary vasculature. |
| Databáze: | OpenAIRE |
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