scholarly journals Human arterial responses to isometric exercise: the role of the muscle metaboreflex

2006 ◽  
Vol 20 (4) ◽  
Author(s):  
Thomas Davies ◽  
Ross Campbell ◽  
Michael Frenneaux ◽  
Michael White
Keyword(s):  
Isometric Exercise ◽  
Muscle Metaboreflex ◽  
Arterial Responses

Human arterial responses to isometric exercise: the role of the muscle metaboreflex

2007 ◽  
Vol 112 (8) ◽  
pp. 441-447 ◽  
Author(s):  
Tom S. Davies ◽  
Michael P. Frenneaux ◽  
Ross I. Campbell ◽  
Michael J. White
Keyword(s):  
Plantar Flexion ◽  
Isometric Exercise ◽  
Arterial Tree ◽  
Contralateral Limb ◽  
Post Exercise ◽  
Muscle Metaboreflex ◽  
Calf Exercise ◽  
Exercise Induced ◽  
Arterial Responses

The effects of exercise on the distensibility of large and medium-sized arteries are poorly understood, but can be attributed to a combination of local vasodilator effects of exercise opposed by sympathetic vasoconstrictor tone. We sought to examine this relationship at the conduit artery level, with particular reference to the role of the sympatho-excitatory muscle metaboreflex. The effect of maintained muscle metaboreflex activation on a previously passive or exercised limb femoral artery was investigated. A total of ten healthy volunteers performed 2 min of isometric ankle plantar-flexion at 40% MVC (maximal voluntary force), in conjunction with 2 min of either non-ischaemic isometric HG (handgrip; control condition) or IHG (ischaemic HG) at 40% MVC. IHG was followed by 2 min of PECO (post-exercise circulatory occlusion) to maintain muscle metaboreflex activation. FTPWV [femoral–tibial PWV (pulse wave velocity)] was measured in the exercised or contralateral limb at baseline and immediately following calf exercise. BP (blood pressure) and HR (heart rate) were measured continuously throughout. In the HG condition, BP and HR returned promptly to baseline post-exercise, whereas exercised leg FTPWV was decreased (less stiff) by 0.6 m/s (P<0.05) and the non-exercised leg PWV was not changed from baseline. PECO caused a sustained increase in BP, but not HR, in the IHG condition. Contralateral leg PWV increased (stiffened) during PECO by 0.9 m/s (P<0.05), whereas exercised limb FTPWV was not changed from baseline. In conclusion, muscle metaboreflex activation causes a systemic stiffening of the arterial tree, which can overcome local exercise-induced decreases in arterial PWV.

scholarly journals Role of endothelial nitric oxide in control of peripheral vascular conductance during muscle metaboreflex activation

2017 ◽  
Vol 313 (1) ◽  
pp. R29-R34
Author(s):  
Danielle Senador ◽  
Jasdeep Kaur ◽  
Alberto Alvarez ◽  
Hanna W. Hanna ◽  
Abhinav C. Krishnan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Vascular Conductance ◽  
Muscle Metaboreflex ◽  
Peripheral Vasodilation ◽  
Dependent Flow ◽  
Flow Mediated Vasodilation ◽  
The Relationship

The muscle metaboreflex is a powerful pressor reflex induced by the activation of chemically sensitive muscle afferents as a result of metabolite accumulation. During submaximal dynamic exercise, the rise in arterial pressure is primarily due to increases in cardiac output, since there is little systemic vasoconstriction. Indeed, in normal animals, we have often shown a small, but significant, peripheral vasodilation during metaboreflex activation, which is mediated, at least in part, by release of epinephrine and activation of vascular β2-receptors. We tested whether this vasodilation is in part due to increased release of nitric oxide caused by the rise in cardiac output eliciting endothelium-dependent flow-mediated vasodilation. The muscle metaboreflex was activated via graded reductions in hindlimb blood flow during mild exercise with and without nitric oxide synthesis blockade [ NG-nitro-l-arginine methyl ester (l-NAME); 5 mg/kg]. We assessed the role of increased cardiac output in mediating peripheral vasodilation via the slope of the relationship between the rise in nonischemic vascular conductance (conductance of all vascular beds excluding hindlimbs) vs. the rise in cardiac output. l-NAME increased mean arterial pressure at rest and during exercise. The metaboreflex-induced increases in mean arterial pressure were unaltered by l-NAME, whereas the increases in cardiac output and nonischemic vascular conductance were attenuated. However, the slope of the relationship between nonischemic vascular conductance and cardiac output was not affected by l-NAME, indicating that the rise in cardiac output did not elicit vasodilation via increased release of nitric oxide. Thus, although nitric oxide is intrinsic to the vascular tonus, endothelial-dependent flow-mediated vasodilation plays little role in the small peripheral vasodilation observed during muscle metaboreflex activation.

Role of Endothelin-1 in Choroidal Blood Flow Regulation during Isometric Exercise in Healthy Humans

2003 ◽  
Vol 44 (2) ◽  
pp. 728 ◽  
Author(s):  
Gabriele Fuchsja¨ger-Mayrl ◽  
Alexandra Luksch ◽  
Magdalena Malec ◽  
Elzbieta Polska ◽  
Michael Wolzt ◽  
...  
Keyword(s):  
Blood Flow ◽  
Isometric Exercise ◽  
Flow Regulation ◽  
Choroidal Blood Flow ◽  
Endothelin 1 ◽  
Healthy Humans ◽  
Blood Flow Regulation

scholarly journals Evidence for the Role of Isometric Exercise Training in Reducing Blood Pressure: Potential Mechanisms and Future Directions

2013 ◽  
Vol 44 (3) ◽  
pp. 345-356 ◽  
Author(s):  
Philip J. Millar ◽  
Cheri L. McGowan ◽  
Véronique A. Cornelissen ◽  
Claudio G. Araujo ◽  
Ian L. Swaine
Keyword(s):  
Blood Pressure ◽  
Exercise Training ◽  
Isometric Exercise ◽  
Pressure Potential ◽  
Future Directions

Role Of The Muscle Metaboreflex In Cardiovascular Responses To Apnea During Exercise In Humans

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S268
Author(s):  
Mayumi Matsumoto ◽  
Naoto Fujii ◽  
Masashi Ichinose ◽  
Takeshi Nishiyasu
Keyword(s):  
Cardiovascular Responses ◽  
Muscle Metaboreflex ◽  
Exercise In Humans

Role of nitric oxide in optic nerve head blood flow regulation during isometric exercise in healthy humans

2010 ◽  
Vol 88 ◽  
pp. 0-0
Author(s):  
D SCHMIDL ◽  
A BOLTZ ◽  
M LASTA ◽  
S KAYA ◽  
B PEMP ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Isometric Exercise ◽  
Flow Regulation ◽  
Healthy Humans ◽  
Blood Flow Regulation

scholarly journals Augmented Hemodynamic Responses in Obese Young Men during Dynamic Exercise: Role of the Muscle Metaboreflex

2020 ◽  
Vol 17 (19) ◽  
pp. 7321
Author(s):  
Byung-Sun Lee ◽  
Kyung-Ae Kim ◽  
Jong-Kyung Kim ◽  
Hosung Nho
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Response ◽  
Cardiovascular Responses ◽  
Normal Weight ◽  
Dynamic Exercise ◽  
Handgrip Exercise ◽  
Vascular Conductance ◽  
Post Exercise ◽  
Muscle Metaboreflex

Studies found that cardiovascular responses to exercise are enhanced in individuals with obesity and are associated with a greater cardiac output (CO) response compared to normal weight controls. However, the mechanisms underlying these altered responses during dynamic exercise are not clear. We investigated whether the cardiovascular responses mediated by the muscle metaboreflex (MMR) activation are augmented in obese men during both static and dynamic exercise. Twenty males (10 obese (OG) and 10 non-obese (NOG)) were studied. Changes in CO, mean arterial pressure (MAP), and total vascular conductance (TVC) were compared between the two groups during dynamic handgrip exercise (DHE), post-exercise muscular ischemia (PEMI), and dynamic exercise corresponding to 40%, 60% and 80% workloads. Subjects completed 2 min of DHE at 30% of MVC, followed by 2 min of PEMI. MAP, CO, and TVC responses to DHE and dynamic exercise were significantly higher in OG, whereas there were no differences during PEMI. Increases in CO and MAP during mild to heavy dynamic exercise were seen in both groups, but the changes in these variables were greater in the OG. There were no significant differences in TVC between the two groups. Compared to NOG, the augmented blood pressure response to DHE and dynamic exercise in OG was associated with a greater increase in CO. Thus, the augmented CO and MAP responses were not associated with the activation of the MMR. Consequently, additional factors specific to obesity, such as the mechanoreflex, may have been involved.

Role of NO in Choroidal Blood Flow Regulation during Isometric Exercise in Healthy Humans

2003 ◽  
Vol 44 (2) ◽  
pp. 734 ◽  
Author(s):  
Alexandra Luksch ◽  
Elzbieta Polska ◽  
Andrea Imhof ◽  
Joanne Schering ◽  
Gabriele Fuchsja¨ger-Mayrl ◽  
...  
Keyword(s):  
Blood Flow ◽  
Isometric Exercise ◽  
Flow Regulation ◽  
Choroidal Blood Flow ◽  
Healthy Humans ◽  
Blood Flow Regulation
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