The Effect of Norepinephrine on the Coronary Microcirculation
| Autor: | Frank W. Sellke, Peter F. Banitt, David G. Harrison, James E. Quillen |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Sympathetic nervous system
medicine.medical_specialty Swine Physiology Adrenergic Coronary microcirculation Nitric Oxide Norepinephrine (medication) Norepinephrine chemistry.chemical_compound Coronary Circulation Internal medicine Receptors Adrenergic beta Animals Medicine Cyclic GMP business.industry Microcirculation Endothelium-derived relaxing factor Propranolol Tone (literature) Vasodilation Coronary arteries medicine.anatomical_structure chemistry Aminoquinolines Cardiology SRS-A Cardiology and Cardiovascular Medicine business medicine.drug Artery |
| Zdroj: | Journal of Vascular Research. 29:2-7 |
| ISSN: | 1423-0135 1018-1172 |
| DOI: | 10.1159/000158924 |
| Popis: | The role of the sympathetic nervous system in the regulation of large coronary artery tone has been well defined. Studies of adrenergic regulation of coronary-resistance vessels have largely been limited to indirect inferences based on flow measurement obtained in vivo. The purpose of the present study was to determine the effects of norepinephrine (NE) on the coronary microcirculation using direct in vitro approaches. Porcine coronary microvessels (80-200 microns in diameter) were pressurized in isolated organ chambers. Diameters were measured using a Halpern microvessel imaging apparatus. After preconstriction with leukotriene D4, NE caused complete relaxation. Relaxations to NE were inhibited by propranolol. Relaxations to NE were also inhibited by LY83583 (which depletes cGMP) and hemoglobin (which binds endothelium-derived relaxing factor, EDRF). NE caused minimal or no constriction in both preconstricted and nonpreconstricted microvessels even in the presence of hemoglobin and propranolol. In conclusion, NE predominantly dilates porcine coronary microvessels, both by beta-adrenoceptor activation and by stimulating release of EDRF. There is minimal alpha-adrenoceptor-mediated constriction of coronary microvessels. |
| Databáze: | OpenAIRE |
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