Catecholamines can induce adenosine receptor-mediated protection of the myocardium but do not participate in ischemic preconditioning in the rabbit
| Autor: | James M. Downey, Michael V. Cohen, Xi-Ming Yang, J F Daly, J. D. Thornton |
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| Rok vydání: | 1993 |
| Předmět: |
Male
medicine.medical_specialty Adenosine Physiology Myocardial Ischemia Ischemia Tyramine Hemodynamics Infarction Propranolol Catecholamines Species Specificity Internal medicine medicine Animals business.industry Receptors Purinergic Receptors Adrenergic alpha medicine.disease Adenosine receptor Rats Endocrinology Coronary occlusion Cardiology Ischemic preconditioning Female Rabbits Cardiology and Cardiovascular Medicine business medicine.drug |
| Zdroj: | Circulation Research. 73:649-655 |
| ISSN: | 1524-4571 0009-7330 |
| DOI: | 10.1161/01.res.73.4.649 |
| Popis: | The role of catecholamines in ischemic preconditioning is unclear. Accordingly, the effects of tyramine-induced norepinephrine release and alpha 1-receptor blockade were examined. Ischemic preconditioning with a 5-minute coronary occlusion 10 minutes before a 30-minute ischemic interval resulted in only 7.7 +/- 3.1% infarction of the risk area, significantly less than that in control rabbits with isolated 30-minute coronary occlusions (34.4 +/- 3.2%, P < .01). Intravenous infusion of tyramine 10 minutes before 30 minutes of ischemia also protected the heart from infarction to an extent similar to that seen with ischemic preconditioning (6.9 +/- 2.4% infarction). This protection observed with tyramine infusion was eliminated by alpha 1-receptor blockade with BE 2254 (36.8 +/- 2.6% infarction) but was unaffected by beta-blockade with propranolol (10.5 +/- 2.4% infarction). Furthermore, the protection was unaffected when the tyramine-induced hypertension was attenuated by allowing blood to flow into a volume reservoir (3.9 +/- 0.8% infarction, P < .01 vs control value). The nonselective adenosine-receptor blocker PD 115,199 also eliminated tyramine-induced protection (40.2 +/- 5.6% infarction), indicating that adenosine is involved in adrenergic-mediated protection. BE 2254 could not block ischemic preconditioning (3.9 +/- 1.1% infarction, P < .01 vs control value). Therefore, catecholamine release before prolonged ischemia can protect the heart from infarction via the alpha 1-receptor, but adenosine receptor stimulation is also involved. alpha-Adrenergic stimulation does not appear to be critical to the protection observed after ischemic preconditioning. |
| Databáze: | OpenAIRE |
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