Importance of basal nitric oxide synthesis in regulation of myocardial blood flow
| Autor: | Csaba Szabó, Csilla Csáki, A. G. B. Kovách, Gergely Kiss, Zoltán Benyó |
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| Rok vydání: | 1991 |
| Předmět: |
Male
medicine.medical_specialty Mean arterial pressure Endothelium Physiology Blood Pressure Arginine Nitric Oxide Nitroarginine Nitric oxide chemistry.chemical_compound Physiology (medical) Internal medicine Infusion Procedure Coronary Circulation Medicine Animals business.industry Blood flow Coronary Vessels Microspheres medicine.anatomical_structure Blood pressure chemistry Anesthesia Vascular resistance Cardiology Cats Vascular Resistance Endothelium Vascular Cardiology and Cardiovascular Medicine business Perfusion |
| Zdroj: | Cardiovascular research. 25(8) |
| ISSN: | 0008-6363 |
| Popis: | Study objective — The aim was to investigate whether basal coronary vascular tone and myocardial perfusion depend upon endothelial nitric oxide (NO) synthesis. Design — Myocardial blood flow and vascular resistance of the left and right ventricles were studied before and after intravenous infusions of either NG-nitro-L-arginine (L-NA), a specific inhibitor of NO synthase, or L-arginine, the precursor of NO synthesis. Radiolabelled microspheres were used to study myocardial blood flow in small tissue sections. Experimental material — 14 anaesthetised male cats, weight 2.1-3.5 kg, were used. Measurements and main results — Measurements were made before and 15 and 40 min after L-NA treatment (30 mg·kg−1 bolus followed by 1 mg·kg−1·min−1 infusion; n=8), and before and 15 min after L-arginine treatment (30 mg·kg−1 bolus followed by 10 mg·kg−1·min−1 infusion; n=6). L-NA significantly reduced coronary blood flow to the left and right ventricle, by 30(SEM 9) and 48(6)% respectively, after 15 min, but only to the right ventricle, by 45(8)%, after 40 min. Mean arterial pressure and myocardial vascular resistance were raised during the L-NA infusion. In contrast, L-arginine did not elicit any change in the variables studied. Conclusions — The conductance of the coronary vascular bed and the resting myocardial blood flow is regulated by L-arginine derived nitric oxide, and exogenous L-arginine availability is not a limiting factor in this NO generation. |
| Databáze: | OpenAIRE |
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