Cardiovascular effects of NG-methyl-L-arginine in chronically instrumented conscious dogs
| Autor: | Marie-Francoise Doursout, T. Lechevalier, Jacques E. Chelly, R. G. Kilbourn |
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| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty Mean arterial pressure Cardiac output Physiology Blood Pressure Hematocrit Arginine Nitric Oxide Body Temperature Nitric oxide chemistry.chemical_compound Dogs Physiology (medical) Internal medicine Heart rate medicine Animals Cardiac Output omega-N-Methylarginine medicine.diagnostic_test biology business.industry Hemodynamics Nitric oxide synthase chemistry Regional Blood Flow Cardiology biology.protein Ventricular pressure Omega-N-Methylarginine Female Amino Acid Oxidoreductases Blood Gas Analysis Nitric Oxide Synthase business |
| Zdroj: | Journal of Applied Physiology. 77:471-475 |
| ISSN: | 1522-1601 8750-7587 |
| Popis: | The cardiovascular effects of nitric oxide blockade were examined in five conscious chronically instrumented dogs. The hypothesis tested was that nitric oxide release plays a role in vascular tone and regional organ blood flow under physiological conditions. Aortic pressures; the first derivative of the left ventricular pressure; cardiac output (CO); heart rate; and carotid, coronary, renal, hepatic, and portal blood flows were recorded before and after bolus injection of 5, 10, and 20 mg/kg of NG-methyl-L-arginine (L-NMA). In response to L-NMA, mean arterial pressure increased by 7, 20, and 35%, respectively, in a dose-dependent manner, whereas CO decreased. CO reduction was sustained at the highest dose, whereas peripheral blood flows were not altered. These data suggest that blocking basal nitric oxide synthesis by administering L-NMA leads to a modest dose-dependent pressor response despite a marked and sustained reduction in CO recorded at the highest dose of L-NMA. Moreover, within our dose range, although the nitric oxide synthase inhibition provides a significant pressor response, it does not alter the resting carotid, coronary, renal, hepatic, and portal blood flows. |
| Databáze: | OpenAIRE |
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