Blunted Hyperemic Response to Mental Stress in Young, Non-Hispanic Black Men is not Impacted by Acute Dietary Nitrate Supplementation

2021 ◽  
Author(s):  
John D. Akins ◽  
Bryon M. Curtis ◽  
Jordan C. Patik ◽  
Guillermo Olvera ◽  
Aida Nasirian ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Function ◽  
Mental Stress ◽  
Forearm Blood Flow ◽  
Phase 1 ◽  
Nitrate Content ◽  
Phase 2 ◽  
Dietary Nitrate ◽  
Nitrate Supplementation ◽  
No Bioavailability

Non-Hispanic black individuals have an elevated prevalence of cardiovascular disease in large part, related to impaired vascular function, secondary to reduced nitric oxide (NO) bioavailability. Nitrate supplementation increases NO bioavailability and improves vascular function. This study tested the hypothesis that forearm blood flow responses in young, non-Hispanic, black (BL) men during mental stress are blunted relative to, non-Hispanic, white (WH) men and that acute dietary nitrate supplementation would improve this response in BL men. This study was comprised of two parts. Phase 1 investigated the blood flow responses between young, BL and WH men whereas Phase 2 investigated the effect of acute nitrate supplementation in a subset of the BL men. Eleven (9 for Phase 2) BL and 8 WH men (23 ± 3 vs. 24 ± 4 y, respectively) participated. During each visit, brachial artery blood flow was assessed during 3 min of mental stress. Phase 1 was completed in one visit, while Phase 2 was completed over two visits separated by ~1-wk. During Phase 2, data were collected before and 2-h post-consumption of a beverage high in nitrate content or nitrate depleted. In Phase 1, peak forearm blood flow (FBF, P < 0.01), total FBF (P < 0.05), and forearm vascular conductance (P < 0.001) were blunted in the BL. During Phase 2, pre-beverage responses were unaffected following beverage consumption (P > 0.05 for all). Young, BL men have blunted microvascular vasodilatory responses to acute mental stress, which may not be altered following acute nitrate supplementation.

scholarly journals Racial Differences in Vascular Function in Response to Mental Stress: Role of Acute Dietary Nitrate Supplementation

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Jeremiah C. Campbell ◽  
John D. Akins ◽  
Guillermo Olvera ◽  
Bryon M. Curtis ◽  
David M. Keller ◽  
...  
Keyword(s):  
Racial Differences ◽  
Vascular Function ◽  
Mental Stress ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

scholarly journals The Vascular Side of Chronic Bed Rest: When a Therapeutic Approach Becomes Deleterious

2020 ◽  
Vol 9 (4) ◽  
pp. 918 ◽  
Author(s):  
Anna Pedrinolla ◽  
Alessandro L. Colosio ◽  
Roberta Magliozzi ◽  
Elisa Danese ◽  
Emine Kirmizi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Rate ◽  
Vascular Function ◽  
Inflammatory Markers ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Vascular Inflammation ◽  
Bed Rest ◽  
Total Hemoglobin ◽  
No Bioavailability

The interplay between chronic constraint and advanced aging on blood flow, shear-rate, vascular function, nitric oxide (NO)-bioavailability, microcirculation, and vascular inflammation factors is still a matter of debate. Ninety-eight individuals (Young, n = 28, 23 ± 3 yrs; Old, n = 36, 85 ± 7 yrs; Bedridden, n = 34, 88 ± 6 yrs) were included in the study. The bedridden group included old individuals chronically confined to bed (3.8 ± 2.3 yrs). A blood sample was collected and analyzed for plasma nitrate, and vascular inflammatory markers. Hyperemic response (∆peak) during the single passive leg movement (sPLM) test was used to measure vascular function. Skeletal muscle total hemoglobin was measured at the vastus lateralis during the sPLM test, by means of near infrared spectroscopy (NIRS). Bedridden subjects revealed a depletion of plasma nitrates compared with Old (−23.8%) and Young (−31.1%). Blood flow was lower in the Bedridden in comparison to Old (−20.1%) and Young (−31.7%). Bedridden presented lower sPLM ∆peak compared Old (−72.5%) and the Young (−83.3%). ∆peak of NIRS total hemoglobin was lower in the Bedridden compared to that in the Young (−133%). All vascular inflammatory markers except IL-6 were significantly worse in the Bedridden compared to Old and Young. No differences were found between the Old and Young in inflammatory markers. Results of this study confirm that chronic physical constraint induces an exacerbation of vascular disfunction and differential regulation of vascular-related inflammatory markers. The mechanisms involved in these negative adaptations seems to be associated with endothelial dysfunction and consequent diminished NO-bioavailability likely caused by the reduced shear-rate consequential to long-term reduction of physical activity.

Dose-dependent thrombus resolution due to oral plasminogen activator inhibitor (PAI)-1 inhibition with tiplaxtinin in a rat stenosis model of venous thrombosis

2008 ◽  
Vol 99 (04) ◽  
pp. 749-758 ◽  
Author(s):  
Sanjiv Baxi ◽  
David Crandall ◽  
Thomas Meier ◽  
Shirley Wrobleski ◽  
Angela Hawley ◽  
...  
Keyword(s):  
Blood Flow ◽  
Inferior Vena Cava ◽  
Venous Thrombosis ◽  
Inferior Vena ◽  
Phase 1 ◽  
Vena Cava ◽  
Phase 2 ◽  
Oral Gavage ◽  
Dose Dependent ◽  
Pai 1

SummaryThis study aimed to evaluate a small-molecule PAI-1 inhibitor (PAI-039; tiplaxtinin) in a rodent stenosis model of venous thrombosis in a two-phase experiment. Phase 1 determined the efficacy of tiplaxtinin against Lovenox (LOV), while phase 2 determined the dose-dependent efficacy. For both phases, drug treatment began 24 hours after surgically induced venous thrombosis and continued for four days. Phase 1 animals (n = 24) receiving low-dose (LD; 1 mg/kg oral gavage) PAI-1 inhibitor demonstrated a 52% decrease in thrombus weight (TW) versus controls (p < 0.05) with significant reductions in active plasma PAI-1, while the high-dose (HD; 10 mg/kg oral gavage) group demonstrated a 23% reduction in TW versus controls. Animals treated subcutaneously with LOV (3 mg/kg) showed a 39% decrease in TW versus controls (p < 0.05). Coagulation tests (aPTT and TCT) were significantly different in LOV compared to PAI-1 inhibitor groups. PAI-039 treatment was also associated with significantly increased return of inferior vena cava blood flow four days post-thrombosis versus controls (p < 0.05). In phase 2 (n = 30), TW was reduced from the 0.5 mg/kg to 5 mg/ kg experimental groups, with the 10 mg/kg group demonstrating a paradoxical increase. The 5 mg/kg group showed statistically significant decreases in TW versus controls after four treatment days (p < 0.05). This is the first study to demonstrate dose related effects of PAI-039 on increasing thrombus resolution and inferior vena cava blood flow without adverse effects on anti-coagulation in a rat stenosis model of venous thrombosis.

Cardiovascular and Sympatho-Adrenal Responses to Mental Stress in Primary Hypertension

1993 ◽  
Vol 85 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Madeleine Lindqvist ◽  
Thomas Kahan ◽  
Anders Melcher ◽  
Paul Hjemdahl
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Neuropeptide Y ◽  
Mental Stress ◽  
Forearm Blood Flow ◽  
Primary Hypertension ◽  
Hypertensive Patients ◽  
Control Subjects ◽  
Venous Plasma

1. Eleven untreated men with mild to moderate primary hypertension and 10 normotensive control subjects were studied at rest and during a mental stress test (Stroop colour word conflict test), which has previously been used in studies of hypertensive patients with regard to non-invasive cardiovascular variables and venous plasma catecholamine concentrations. 2. Heart rate, central cardiovascular pressures, cardiac output (thermodilution) and forearm blood flow (strain gauge plethysmography) were determined. Systemic and forearm vascular resistances were calculated. Arterial and venous plasma adrenaline and noradrenaline concentrations were measured by h.p.l.c., and arterial noradrenaline spillover and noradrenaline overflow from the forearm were assessed by isotope methodology ([3H]noradrenaline). Neuropeptide Y-like immunoreactivity was measured by radioimmunoassay. 3. In hypertensive patients heart rate, arterial blood pressure, cardiac output and forearm blood flow increased by 28%, 13%, 37% and 115%, respectively, and forearm and systemic vascular resistances decreased by 48% and 21%, respectively (P <0.001 for all responses), during stress. These responses were not different from those of the control group. 4. Arterial noradrenaline spillover rose by 63% and noradrenaline overflow from the forearm rose by 150% in the hypertensive patients in response to mental stress (P <0.001); no significant group differences could be demonstrated. However, the forearm noradrenaline overflow response to stress tended to be greater in the hypertensive group (P = 0.11). Arterial adrenaline concentrations doubled in both groups (P <0.001). 5. Arterial neuropeptide Y-like immunoreactivity increased slightly and similarly in the two groups (+7% in hypertensive patients and +9% in control subjects, P <0.05 for both) in response to mental stress. No net overflow of neuropeptide-Y-like immunoreactivity could be detected over the forearm. 6. It is concluded that the cardiovascular and sympatho-adrenal responses to mental stress evaluated in this study are similar in hypertensive patients and control subjects. Stress-induced vasodilatation occurs in the forearm despite signs of increased local sympathetic activity, indicating that powerful neurohormonal vasodilator mechanisms are activated by mental stress.

Forearm Vasoreactivity in Type I Diabetic Subjects

2001 ◽  
Vol 26 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Jason D. Allen ◽  
Michael Welsch ◽  
Nikki Aucoin ◽  
Robert Wood ◽  
Matt Lee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Flow ◽  
Vascular Function ◽  
Forearm Blood Flow ◽  
Reactive Hyperemia ◽  
Arterial Occlusion ◽  
Type I ◽  
Handgrip Exercise ◽  
Blood Flows

This study compared forearm vasoreactivity in 15 Type 1 diabetic subjects with 15 healthy controls. The groups were matched for age, exercise capacity, and the absence of other cardiovascular risk factors. Vasoreactivity was measured using strain gauge plethysmography, at rest, after arterial occlusion (OCC), and following OCC coupled with handgrip exercise (ROCC). Forearm blood flows were significantly elevated between conditions 2.58 ± 0.37 ml/100mltissue at rest to 26.80 ± 6.56 after OCC and 32.80 ± 8.26ml/100mltissue following ROCC in Type 1 diabetic subjects. There were no differences in forearm blood flow between groups for any of the conditions. These data indicate the degree of forearm blood flow is directly related to the intensity of the vasodilatory stimulus. However, our study did not reveal evidence of impaired vasodilatory capacity in Type 1 diabetic subjects compared to controls in the absence of other risk factors. Key words: IDDM, vascular function, exercise, fitness, and reactive hyperemia

scholarly journals Dietary nitrate supplementation opposes the elevated diaphragm blood flow in chronic heart failure during submaximal exercise

2018 ◽  
Vol 247 ◽  
pp. 140-145 ◽  
Author(s):  
Joshua R. Smith ◽  
Scott K. Ferguson ◽  
K. Sue Hageman ◽  
Craig A. Harms ◽  
David C. Poole ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Flow ◽  
Chronic Heart Failure ◽  
Submaximal Exercise ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

scholarly journals Nitric oxide contributes to the rise in forearm blood flow during mental stress in humans.

1994 ◽  
Vol 480 (2) ◽  
pp. 361-368 ◽  
Author(s):  
N M Dietz ◽  
J M Rivera ◽  
S E Eggener ◽  
R T Fix ◽  
D O Warner ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Mental Stress ◽  
Forearm Blood Flow

scholarly journals Dietary nitrate supplementation enhances cerebrovascular CO2 reactivity in a sex-specific manner

2019 ◽  
Vol 127 (3) ◽  
pp. 760-769 ◽  
Author(s):  
Jui-Lin Fan ◽  
Terrence O’Donnell ◽  
Clint Lee Gray ◽  
Kevin Croft ◽  
Annabel Kate Noakes ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Autoregulation ◽  
Brain Blood Flow ◽  
Healthy Individuals ◽  
Dietary Nitrate ◽  
Cerebrovascular Function ◽  
Transfer Function Analysis ◽  
Specific Manner ◽  
Nitrate Supplementation

Insufficient nitric oxide (NO) bioavailability plays an important role in endothelial dysfunction, and increased NO has the potential to enhance cerebral blood flow (CBF). Dietary supplementation with sodium nitrate, a precursor of NO, could improve cerebrovascular function, but this has not been investigated. In 17 individuals, we examined the effects of a 7-day supplementation of dietary nitrate (0.1 mmol·kg−1·day −1) on cerebrovascular function using a randomized, single-blinded placebo-controlled crossover design. We hypothesized that 7-day dietary nitrate supplementation increases CBF response to CO2 (cerebrovascular CO2 reactivity) and cerebral autoregulation (CA). We assessed middle cerebral artery blood velocity (MCAv) and blood pressure (BP) at rest and during CO2 breathing. Transfer function analysis was performed on resting beat-to-beat MCAv and BP to determine CA, from which phase, gain, and coherence of the BP-MCAv data were derived. Dietary nitrate elevated plasma nitrate concentration by ~420% ( P < 0.001) and lowered gain ( d = 1.2, P = 0.025) and phase of the BP-MCAv signal compared with placebo treatment ( d = 0.7, P = 0.043), while coherence was unaffected ( P = 0.122). Dietary nitrate increased the MCAv-CO2 slope in a sex-specific manner (interaction: P = 0.016). Dietary nitrate increased the MCAv-CO2 slope in men ( d = 1.0, P = 0.014 vs. placebo), but had no effect in women ( P = 0.919). Our data demonstrate that dietary nitrate greatly increased cerebrovascular CO2 reactivity in healthy individuals, while its effect on CA remains unclear. The selective increase in the MCAv-CO2 slope observed in men indicates a clear sexual dimorphic role of NO in cerebrovascular function. NEW & NOTEWORTHY We found dietary nitrate supplementation improved the brain blood vessels’ response to CO2, cerebrovascular CO2 reactivity, without affecting blood pressure in a group of healthy individuals. Meanwhile, the effect of dietary nitrate on the relationship between blood pressure and brain blood flow, cerebral autoregulation, was inconclusive. The improvement in cerebrovascular CO2 reactivity was only observed in the male participants, alluding to a sex difference in the effect of dietary nitrate on brain blood flow control. Our findings indicate that dietary nitrate could be an effective strategy to enhance cerebrovascular CO2 reactivity.

scholarly journals Perfusion pressure and movement-induced hyperemia: evidence of limited vascular function and vasodilatory reserve with age

2013 ◽  
Vol 304 (4) ◽  
pp. H610-H619 ◽  
Author(s):  
H. Jonathan Groot ◽  
Joel D. Trinity ◽  
Gwenael Layec ◽  
Matthew J. Rossman ◽  
Stephen J. Ives ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Function ◽  
Perfusion Pressure ◽  
The Elderly ◽  
Passive Movement ◽  
Hemodynamic Responses ◽  
Central Hemodynamic ◽  
Seated Posture ◽  
No Bioavailability ◽  
The Impact

To better understand the mechanisms contributing to reduced blood flow with age, this study sought to elucidate the impact of altered femoral perfusion pressure (FPP) on movement-induced hyperemia. Passive leg movement was performed in 10 young (22 ± 1 yr) and 12 old (72 ± 2 yr) healthy men for 2 min, with and without a posture-induced change in FPP (∼7 ± 1 ΔmmHg). Second-by-second measurements of central and peripheral hemodynamic responses were acquired noninvasively (finger photoplethysmography and Doppler ultrasound, respectively), with FPP confirmed in a subset of four young and four old subjects with arterial and venous catheters. Central hemodynamic responses (heart rate, stroke volume, cardiac output, mean arterial pressure) were not affected by age or position. The young exhibited a ∼70% greater movement-induced peak change in leg blood flow (ΔLBFpeak) in the upright-seated posture (supine: 596±68 ml/min; upright: 1,026 ± 85 ml/min). However, in the old the posture change did not alter ΔLBFpeak (supine: 417±42 ml/min; upright: 412±56 ml/min), despite the similar increases in FPP. Similarly, movement-induced peak change in leg vascular conductance was ∼80% greater for the young in the upright-seated posture (supine: 7.1 ± 0.8 ml·min−1·mmHg−1; upright: 12.8 ± 1.3 ml·min−1·mmHg−1), while the old again exhibited no difference between postures (supine: 4.7 ± 0.4 ml·min−1·mmHg−1; upright: 4.8 ± 0.5 ml·min−1·mmHg−1). Thus this study reveals that, unlike the young, increased FPP does not elicit an increase in movement-induced hyperemia or vasodilation in the old. In light of recent evidence that the majority of the first minute of passive movement-induced hyperemia is predominantly nitric oxide (NO) dependent in the young, these findings in the elderly may be largely due to decreased NO bioavailability, but this remains to be definitively determined.

scholarly journals Enhanced forearm blood flow during mental stress in children of hypertensive parents.

Hypertension ◽  
1987 ◽  
Vol 10 (5) ◽  
pp. 544-549 ◽  
Author(s):  
E A Anderson ◽  
L T Mahoney ◽  
R M Lauer ◽  
W R Clarke
Keyword(s):  
Blood Flow ◽  
Mental Stress ◽  
Forearm Blood Flow
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