TY - JOUR
T1 - Exercise training modulates functional sympatholysis and alpha-adrenergic vasoconstrictor responsiveness in hypertensive and normotensive individuals
AU - Mortensen, Stefan Peter
AU - Nyberg, Michael Permin
AU - Gliemann Hybholt, Lasse
AU - Thaning, Pia
AU - Saltin, Bengt
AU - Hellsten, Ylva
N1 - CURIS 2014 NEXS 154
PY - 2014
Y1 - 2014
N2 - Essential hypertension is linked to an increased sympathetic vasoconstrictor activity and reduced tissue perfusion. We investigated the role of exercise training on functional sympatholysis and postjunctional α-adrenergic responsiveness in individuals with essential hypertension. Leg haemodynamics were measured before and after 8 weeks of aerobic training (3-4 times/week) in 8 hypertensive (47 ± 2 years) and 8 normotensive untrained individuals (46 ± 1 years) during arterial tyramine infusion, arterial ATP infusion and/or one-legged knee extensions. Before training, exercise hypaeremia and leg vascular conductance (LVC) were lower in the hypertensive individuals (P < 0.05) and tyramine lowered exercise hypaeremia and VC in both groups (P < 0.05). Training lowered blood pressure in the hypertensive individuals (P < 0.05) and exercise hypaeremia was similar to the normotensive individuals in the trained state. After training, tyramine did not reduce exercise hyperaemia or LVC in either group. When tyramine was infused at rest, the reduction in blood flow and LVC was similar between groups, but exercise training lowered the magnitude of the reduction in blood flow and LVC (P < 0.05). There was no difference in the vasodilatory response to infused ATP or in muscle P2Y2 receptor content between the groups before and after training. However, training lowered the vasodilatory response to ATP and increased skeletal muscle P2Y2 receptor content in both groups (P < 0.05). These results demonstrate that exercise training improves functional sympatholysis and reduces postjunctional α-adrenergic responsiveness in both normo- and hypertensive individuals. The ability for functional sympatholysis and the vasodilator and sympatholytic effect of intravascular ATP appears not to be altered in essential hypertension. This article is protected by copyright. All rights reserved.
AB - Essential hypertension is linked to an increased sympathetic vasoconstrictor activity and reduced tissue perfusion. We investigated the role of exercise training on functional sympatholysis and postjunctional α-adrenergic responsiveness in individuals with essential hypertension. Leg haemodynamics were measured before and after 8 weeks of aerobic training (3-4 times/week) in 8 hypertensive (47 ± 2 years) and 8 normotensive untrained individuals (46 ± 1 years) during arterial tyramine infusion, arterial ATP infusion and/or one-legged knee extensions. Before training, exercise hypaeremia and leg vascular conductance (LVC) were lower in the hypertensive individuals (P < 0.05) and tyramine lowered exercise hypaeremia and VC in both groups (P < 0.05). Training lowered blood pressure in the hypertensive individuals (P < 0.05) and exercise hypaeremia was similar to the normotensive individuals in the trained state. After training, tyramine did not reduce exercise hyperaemia or LVC in either group. When tyramine was infused at rest, the reduction in blood flow and LVC was similar between groups, but exercise training lowered the magnitude of the reduction in blood flow and LVC (P < 0.05). There was no difference in the vasodilatory response to infused ATP or in muscle P2Y2 receptor content between the groups before and after training. However, training lowered the vasodilatory response to ATP and increased skeletal muscle P2Y2 receptor content in both groups (P < 0.05). These results demonstrate that exercise training improves functional sympatholysis and reduces postjunctional α-adrenergic responsiveness in both normo- and hypertensive individuals. The ability for functional sympatholysis and the vasodilator and sympatholytic effect of intravascular ATP appears not to be altered in essential hypertension. This article is protected by copyright. All rights reserved.
U2 - 10.1113/jphysiol.2014.273722
DO - 10.1113/jphysiol.2014.273722
M3 - Journal article
C2 - 24860173
VL - 592
SP - 3063
EP - 3073
JO - The Journal of Physiology
JF - The Journal of Physiology
SN - 0022-3751
IS - 14
ER -