WISE 2005: stroke volume changes contribute to the pressor response during ischemic handgrip exercise in women

2007 ◽  
Vol 103 (1) ◽  
pp. 228-233 ◽  
Author(s):  
J. K. Shoemaker ◽  
L. Mattar ◽  
P. Kerbeci ◽  
S. Trotter ◽  
P. Arbeille ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Stroke Volume ◽  
Portal Vein ◽  
Pressor Response ◽  
Muscle Sympathetic Nerve Activity ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Arterial Blood ◽  
Vein Diameter ◽  
Ischemic Handgrip Exercise

The mechanism of the pressor response to small muscle mass (e.g., forearm) exercise and during metaboreflex activation may include elevations in cardiac output (Q̇) or total peripheral resistance (TPR). Increases in Q̇ must be supported by reductions in visceral venous volume to sustain venous return as heart rate (HR) increases. Therefore, this study tested the hypothesis that increases in Q̇, supported by reductions in splanchnic volume (portal vein constriction), explain the pressor response during handgrip exercise and metaboreflex activation. Seventeen healthy women performed 2 min of static ischemic handgrip exercise and 2 min of postexercise circulatory occlusion (PECO) while HR, stroke volume and superficial femoral artery flow (Doppler), blood pressure (Finometer), portal vein diameter (ultrasound imaging), and muscle sympathetic nerve activity (MSNA; microneurography) were measured followed by the calculation of Q̇, TPR, and leg vascular resistance (LVR). Compared with baseline, mean arterial blood pressure (MAP) ( P < 0.001) and Q̇ ( P < 0.001) both increased in each minute of exercise accompanied by a ∼5% reduction in portal vein diameter ( P < 0.05). MAP remained elevated during PECO, whereas Q̇ decreased below exercise levels. MSNA was elevated above baseline during the second minute of exercise and through the PECO period ( P < 0.05). Neither TPR nor LVR was changed from baseline during exercise and PECO. The data indicate that the majority of the blood pressure response to isometric handgrip exercise in women was due to mobilization of central blood volume and elevated stroke volume and Q̇ rather than elevations in TVR or LVR resistance.

Chemoreflex and metaboreflex control during static hypoxic exercise

2005 ◽  
Vol 288 (4) ◽  
pp. H1724-H1729 ◽  
Author(s):  
Anne Houssiere ◽  
Boutaina Najem ◽  
Agniezka Ciarka ◽  
Sonia Velez-Roa ◽  
Robert Naeije ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Circulatory Arrest ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Isometric Handgrip Exercise ◽  
Baseline Values ◽  
Hypoxic Exercise

To investigate the effects of muscle metaboreceptor activation during hypoxic static exercise, we recorded muscle sympathetic nerve activity (MSNA), heart rate, blood pressure, ventilation, and blood lactate in 13 healthy subjects (22 ± 2 yr) during 3 min of three randomized interventions: isocapnic hypoxia (10% O2) (chemoreflex activation), isometric handgrip exercise in normoxia (metaboreflex activation), and isometric handgrip exercise during isocapnic hypoxia (concomitant metaboreflex and chemoreflex activation). Each intervention was followed by a forearm circulatory arrest to allow persistent metaboreflex activation in the absence of exercise and chemoreflex activation. Handgrip increased blood pressure, MSNA, heart rate, ventilation, and lactate (all P < 0.001). Hypoxia without handgrip increased MSNA, heart rate, and ventilation (all P < 0.001), but it did not change blood pressure and lactate. Handgrip enhanced blood pressure, heart rate, MSNA, and ventilation responses to hypoxia (all P < 0.05). During circulatory arrest after handgrip in hypoxia, heart rate returned promptly to baseline values, whereas ventilation decreased but remained elevated ( P < 0.05). In contrast, MSNA, blood pressure, and lactate returned to baseline values during circulatory arrest after hypoxia without exercise but remained markedly increased after handgrip in hypoxia ( P < 0.05). We conclude that metaboreceptors and chemoreceptors exert differential effects on the cardiorespiratory and sympathetic responses during exercise in hypoxia.

Heat stress attenuates the increase in arterial blood pressure during isometric handgrip exercise

2012 ◽  
Vol 113 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Konrad Binder ◽  
Daniel Gagnon ◽  
Aaron G. Lynn ◽  
Narihiko Kondo ◽  
Glen P. Kenny
Keyword(s):  
Blood Pressure ◽  
Heat Stress ◽  
Arterial Blood Pressure ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Arterial Blood ◽  
Isometric Handgrip Exercise

scholarly journals Effect of age on the hemodynamic and sympathetic responses at the onset of isometric handgrip exercise

2014 ◽  
Vol 116 (2) ◽  
pp. 222-227 ◽  
Author(s):  
Sophie Lalande ◽  
Carolyn P. Sawicki ◽  
Jacquie R. Baker ◽  
J.Kevin Shoemaker
Keyword(s):  
Heart Rate ◽  
Total Peripheral Resistance ◽  
Pressor Response ◽  
Muscle Sympathetic Nerve Activity ◽  
Peripheral Resistance ◽  
Older Individuals ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Vasoconstrictor Response ◽  
Isometric Handgrip Exercise

Cardiac and peripheral vasomotor factors contribute to the rapid pressor response at the onset of isometric handgrip exercise. We tested the hypothesis that age enhances the sympathetic and vasoconstrictor response at the onset of isometric handgrip exercise so that the pressor response is maintained, despite a diminished cardiac function. Twelve young and twelve older (24 ± 3 and 63 ± 8 yr) individuals performed 20-s isometric handgrip exercise at 30, 40, or 50% of maximal voluntary contraction force. Muscle sympathetic nerve activity (MSNA) was measured using microneurography. Mean arterial pressure (MAP) and cardiac output (Q̇) were assessed continuously by finger plethysmography and total peripheral resistance was calculated. MAP increased with the onset of handgrip; this increase was associated with handgrip intensity and was similar in both groups. Heart rate and Q̇ increased with increasing handgrip intensity in both groups, but increases were greater in young vs. older individuals (age × handgrip intensity interaction, P < 0.05). MSNA burst frequency increased ( P < 0.01), while MSNA burst incidence tended to increase ( P = 0.06) with increasing handgrip intensity in both groups. The change in MSNA between baseline and handgrip, for both frequency and incidence, increased with increasing handgrip intensity for both groups. There was no effect of handgrip intensity or age on total peripheral resistance. The smaller heart rate and Q̇ response during the first 20 s of handgrip exercise in older individuals was not accompanied by a greater sympathetic activation or vasoconstrictor response. However, increases in MAP were similar between groups, indicating that the pressor response at the onset of handgrip exercise is preserved with aging.

Baroreflex modulation of muscle sympathetic nerve activity during posthandgrip muscle ischemia in humans

2001 ◽  
Vol 91 (4) ◽  
pp. 1679-1686 ◽  
Author(s):  
Jian Cui ◽  
Thad E. Wilson ◽  
Manabu Shibasaki ◽  
Nicole A. Hodges ◽  
Craig G. Crandall
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Isometric Handgrip ◽  
Nerve Activity ◽  
Arterial Blood ◽  
Muscle Ischemia ◽  
The Relationship

To identify whether muscle metaboreceptor stimulation alters baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA, beat-by-beat arterial blood pressure (Finapres), and electrocardiogram were recorded in 11 healthy subjects in the supine position. Subjects performed 2 min of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 2.5 min of posthandgrip muscle ischemia. During muscle ischemia, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative ( P < 0.001) during posthandgrip muscle ischemia (−201.9 ± 20.4 units · beat−1 · mmHg−1) when compared with control conditions (−142.7 ± 17.3 units · beat−1 · mmHg−1). No significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. However, both curves shifted during postexercise ischemia to accommodate the elevation in blood pressure and MSNA that occurs with this condition. These data suggest that the sensitivity of baroreflex modulation of MSNA is elevated by muscle metaboreceptor stimulation, whereas the sensitivity of baroreflex of modulate heart rate is unchanged during posthandgrip muscle ischemia.

scholarly journals Reductions in Resting Blood Pressure in Young Adults When Isometric Exercise Is Performed Whilst Walking

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Anthony W. Baross ◽  
David A. Hodgson ◽  
Sarah L. Padfield ◽  
Ian L. Swaine
Keyword(s):  
Blood Pressure ◽  
Young Adults ◽  
Isometric Exercise ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Isometric Training ◽  
Arterial Blood ◽  
Resting Blood Pressure ◽  
Before And After ◽  
Isometric Handgrip Exercise

Aerobic and isometric training have been shown to reduce resting blood pressure, but simultaneous aerobic and isometric training have not been studied. The purpose of this study was to compare the changes in resting systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP) after 6 weeks of either (i) simultaneous walking and isometric handgrip exercise (WHG), (ii) walking (WLK), (iii) isometric handgrip exercise (IHG), or control (CON). Forty-eight healthy sedentary participants (age 20.7 ± 1.7 yrs, mass 67.2 ± 10.2 kg, height 176.7 ± 1.2 cm, male n=26, and female n=22) were randomly allocated, to one of four groups (n=12 in each). Training was performed 4 × week−1 and involved either treadmill walking for 30 minutes (WLK), handgrip exercise 3 × 10 s at 20% MVC (IHG), or both performed simultaneously (WHG). Resting SBP, DBP, and MAP were recorded at rest, before and after the 6-week study period. Reductions in resting blood pressure were significantly greater in the simultaneous walking and handgrip group than any other group. These results show that simultaneous walking and handgrip training may have summative effects on reductions in resting blood pressure.

Moderate whole-body heating attenuates the exercise pressor reflex responses in older humans

2021 ◽  
Author(s):  
Jian Cui ◽  
Zhaohui Gao ◽  
Cheryl Blaha ◽  
J. Carter Luck ◽  
Kristen Brandt ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Pressor Response ◽  
Muscle Sympathetic Nerve Activity ◽  
Cardiovascular Responses ◽  
Whole Body ◽  
Isometric Handgrip ◽  
Healthy Humans ◽  
Arterial Blood ◽  
Isometric Handgrip Exercise ◽  
Fatiguing Exercise

Prior reports show that whole-body heat stress attenuates the pressor response to exercise in young healthy subjects. The effects of moderate whole-body heating (WBH, e.g. increase in internal temperature Tcore ~0.4-0.5 °C) or limb heating on sympathetic and cardiovascular responses to exercise in older healthy humans remains unclear. We examined the muscle sympathetic nerve activity (MSNA), mean arterial blood pressure (MAP) and heart rate (HR) in 14 older (62 ± 2 yrs) healthy subjects during fatiguing isometric handgrip exercise and post exercise circulatory occlusion (PECO). The protocol was performed under normothermic, moderate WBH and local limb (i.e. forearm) heating conditions during 3 visits. During the mild WBH stage (increase in Tcore <0.3 °C), HR increased, whereas BP and MSNA decreased from baseline. Under the moderate WBH condition (increase in Tcore ~0.4 °C), BP decreased, HR increased, while MSNA was unchanged from baseline. Compared with the normothermic trial, the absolute MAP during fatiguing exercise and PECO were lower during the WBH trial. Moreover, MSNA and MAP responses (i.e. changes) to fatiguing exercise were also less than those seen during the normothermic trial. Limb heating induced a similar increase in forearm muscle temperature with that seen in the WBH trial (~0.7-1.5 °C). Limb heating did not alter resting MAP, HR or MSNA. The MSNA and hemodynamic responses to exercise in limb heating trial were not different from those in the normothermic trial. These data suggest that moderate WBH attenuates MSNA and BP responses to exercise in older healthy humans.

scholarly journals Sympathetic neural reactivity to mental stress in humans: test-retest reproducibility

2015 ◽  
Vol 309 (11) ◽  
pp. R1380-R1386 ◽  
Author(s):  
Ida T. Fonkoue ◽  
Jason R. Carter
Keyword(s):  
Blood Pressure ◽  
Mental Stress ◽  
Mental Arithmetic ◽  
Pressor Response ◽  
Muscle Sympathetic Nerve Activity ◽  
Intraclass Correlation ◽  
Cold Pressor Test ◽  
Experimental Session ◽  
Arterial Blood ◽  
Single Laboratory

Mental stress consistently increases arterial blood pressure, but this reliable pressor response is often associated with highly variable muscle sympathetic nerve activity (MSNA) responsiveness between individuals. Although MSNA has been shown to be reproducible within individuals at rest and during the cold pressor test (CPT), intraindividual reproducibility of MSNA responsiveness to mental stress has not been adequately explored. The purpose of this study was to examine MSNA reactivity to mental stress across three experimental sessions. Sixteen men and women (age 21 ± 1 yr) performed two experimental sessions within a single laboratory visit and a third experimental session 1 mo later. Each experimental session consisted of a mental stress trial via mental arithmetic and a CPT trial. Blood pressure, heart rate (HR), and MSNA were measured, and the consistencies of these variables were determined using intraclass correlation (Cronbach's α coefficient). MSNA, mean arterial pressure (MAP), and HR were highly reproducible across the baselines preceding mental stress (Cronbach's α ≥ 0.816, P ≤ 0.001) and CPT (Cronbach's α ≥ 0.782, P ≤ 0.001). Across the three mental stress trials, changes in MSNA (Cronbach's α = 0.875; P = 0.001), MAP (Cronbach's α = 0.749; P < 0.001), and HR (Cronbach's α = 0.919; P < 0.001) were reproducible. During CPT, changes in MSNA (Cronbach's α = 0.805; P = 0.008), MAP (Cronbach's α = 0.878; P < 0.001), and HR (Cronbach's α = 0.927; P < 0.001) remained consistent across the three sessions. In conclusion, our findings demonstrate that MSNA reactivity to mental stress is consistent within a single laboratory visit and across laboratory sessions conducted on separate days.

scholarly journals On the Pathology of the dropsy produced by obstruction of the superior and inferior venœ and the portal vein.— Preliminary communication

1907 ◽  
Vol 79 (532) ◽  
pp. 267-283 ◽  
Keyword(s):  
Blood Pressure ◽  
Arterial Pressure ◽  
Portal Vein ◽  
Mean Arterial Blood Pressure ◽  
Normal Limit ◽  
The Body ◽  
Diastolic Filling ◽  
Arterial Blood ◽  
Preliminary Communication ◽  
The Mean

In August, 1903, I published a paper in the ‘Journal of Pathology’(1) in which I demonstrated a method experimentally producing uncompensated hear disease in an animal, which was compatible with life. This method consisted in diminishing the size of the pericardial sac by stitches, so that the diastolic filling of the heart was impeded. The main symptoms of this condition were dropsy and diminution in the amount of urine excreted. As the immediate result of this interference with the action of the heart, there occurred a rise of pressure throughout the whole systemic venous system extending as far back as the capillaries, and a fall of the mean arterial blood-pressure. Further, I found that the pressure in all the veins fell to the normal limit again within the space of about one hour, and that subsequently when dropsy was being produced, the vanous pressure in all parts of the body was normal, and the arterial pressure had almost recovered itself.

scholarly journals Developmental Changes in Hemodynamic Responses and Cardiovagal Modulation during Isometric Handgrip Exercise

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Styliani Goulopoulou ◽  
Bo Fernhall ◽  
Jill A. Kanaley
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Isometric Contraction ◽  
Pressor Response ◽  
Reflex Response ◽  
Group Differences ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Isometric Handgrip Exercise ◽  
Pressor Reflex

The purpose of this study was to examine differences in pressor response and cardiovagal modulation during isometric handgrip exercise (IHG) between children and adults. Beat-to-beat heart rate (HR) and blood pressure were measured in 23 prepubertal children and 23 adults at baseline and during IHG. Cardiovagal modulation was quantified by analysis of HR variability. Mean arterial pressure responses to IHG were greater in adults compared to children (P<.05) whereas there were no group differences in HR responses (P>.05). Children had a greater reduction in cardiovagal modulation in response to IHG compared to adults (P<.05). Changes in mean arterial pressure during IHG were correlated with baseline cardiovagal modulation and force produced during isometric contraction (P<.05). In conclusion, differences in pressor reflex response between children and adults cannot be solely explained by differences in autonomic modulation and appear to be associated with factors contributing to the force produced during isometric contraction.

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