Muscle α-adrenergic responsiveness during exercise and ATP-induced vasodilation in chronic obstructive pulmonary disease patients
| Autor: | Camilla Koch Ryrsø, Bente Klarlund Pedersen, Ulrik Winning Iepsen, Peter Lange, Gregers Druedal Wibe Munch, Stefan P. Mortensen, Niels H. Secher, Pia Thaning |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Male
Quadriceps Muscle/blood supply Adenosine Triphosphate/administration & dosage Physiology Vasodilator Agents Vasodilation 030204 cardiovascular system & hematology Receptors Adrenergic alpha/metabolism Quadriceps Muscle Pulmonary Disease Chronic Obstructive Adenosine Triphosphate 0302 clinical medicine Signal Transduction/drug effects Sympathomimetics Middle Aged Femoral Artery Lower Extremity Tyramine/administration & dosage Femoral Artery/drug effects Cardiology Sympathomimetics/administration & dosage Female Leg blood flow Cardiology and Cardiovascular Medicine Signal Transduction medicine.medical_specialty Lower Extremity/blood supply Tyramine Pulmonary disease 03 medical and health sciences Physiology (medical) Internal medicine medicine Humans Infusions Intra-Arterial Exercise Aged business.industry Vasodilation/drug effects Receptors Adrenergic alpha Surgery Vasoconstriction/drug effects 030228 respiratory system Vasoconstriction Regional Blood Flow Case-Control Studies Vasodilator Agents/administration & dosage Pulmonary Disease Chronic Obstructive/diagnosis α adrenergic Sympathetic vasoconstriction business Functional sympatholysis |
| Zdroj: | Iepsen, U W, Munch, G D W, Ryrsø, C K, Secher, N H, Lange, P, Thaning, P, Pedersen, B K & Mortensen, S P 2018, ' Muscle α-adrenergic responsiveness during exercise and ATP-induced vasodilation in chronic obstructive pulmonary disease patients ', American Journal of Physiology: Heart and Circulatory Physiology, vol. 314, no. 2, pp. H180-H187 . https://doi.org/10.1152/ajpheart.00398.2017 |
| DOI: | 10.1152/ajpheart.00398.2017 |
| Popis: | Sympathetic vasoconstriction is blunted in exercising muscle (functional sympatholysis) but becomes attenuated with age. We tested the hypothesis that functional sympatholysis is further impaired in chronic obstructive pulmonary disease (COPD) patients. We determined leg blood flow and calculated leg vascular conductance (LVC) during 1) femoral-arterial Tyramine infusion (evokes endogenous norepinephrine release, 1 µmol·min−1·kg leg mass−1), 2) one-legged knee extensor exercise with and without Tyramine infusion [10 W and 20% of maximal workload (WLmax)], 3) ATP (0.05 µmol·min−1·kg leg mass−1) and Tyramine infusion, and 4) incremental ATP infusions (0.05, 0.3, and 3.0 µmol·min−1·kg leg mass−1). We included 10 patients with moderate to severe COPD and 8 age-matched healthy control subjects. Overall, leg blood flow and LVC were lower in COPD patients during exercise ( P < 0.05). Tyramine reduced LVC in both groups at 10-W exercise (COPD: −3 ± 1 ml·min−1·mmHg−1and controls: −3 ± 1 ml·min−1·mmHg−1, P < 0.05) and 20% WLmax(COPD: −4 ± 1 ml·min−1·mmHg−1and controls: −3 ± 1 ml·min−1·mmHg−1, P < 0.05) with no difference between groups. Incremental ATP infusions induced dose-dependent vasodilation with no difference between groups, and, in addition, the vasoconstrictor response to Tyramine infused together with ATP was not different between groups (COPD: −0.03 ± 0.01 l·min−1·kg leg mass−1vs. controls: −0.04 ± 0.01 l·min−1·kg leg mass−1, P > 0.05). Compared with age-matched healthy control subjects, the vasodilatory response to ATP is intact in COPD patients and their ability to blunt sympathetic vasoconstriction (functional sympatholysis) as evaluated by intra-arterial Tyramine during exercise or ATP infusion is maintained.NEW & NOTEWORTHY The ability to blunt sympathetic vasoconstriction in exercising muscle and ATP-induced dilation in chronic obstructive pulmonary disease patients remains unexplored. Chronic obstructive pulmonary disease patients demonstrated similar sympathetic vasoconstriction in response to intra-arterial Tyramine during exercise and ATP-induced vasodilation compared with age-matched healthy control subjects. |
| Databáze: | OpenAIRE |
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