Background: Surgeons routinely apply papaverine, lidocaine, or verapamil to produce acute vasodilation and prevent vasospasms during microvascular surgeries. There is evidence that topical vasodilators may induce postoperative endothelial and smooth muscle dysfunction, which would present after the acute vasodilatory effects of the topical drugs wear off. Therefore, the purpose of the current study was to evaluate the lasting effects of papaverine, lidocaine, and verapamil on human deep inferior epigastric perforator artery vasodilatory function after the acute effects of the topical drugs had worn off.
View Article and Find Full Text PDFHeightened muscle sympathetic nerve activity (MSNA) contributes to impaired vasodilatory capacity and vascular dysfunction associated with aging and cardiovascular disease. The contribution of elevated MSNA to the vasodilatory response during passive leg movement (PLM) has not been adequately addressed. This study sought to test the hypothesis that elevated MSNA diminishes the vasodilatory response to PLM in healthy young males (n = 11, 25 ± 2 year).
View Article and Find Full Text PDFThis study aimed to determine which physiological factors impact net efficiency (ηnet) in oldest-old individuals at different stages of skeletal muscle disuse. To this aim, we examined ηnet, central haemodynamics, peripheral circulation, and peripheral factors (skeletal muscle fibre type, capillarization and concentration of mitochondrial DNA [mtDNA]). Twelve young (YG; 25 ± 2 years), 12 oldest-old mobile (OM; 87 ± 3 years), and 12 oldest-old immobile (OI; 88 ± 4 years) subjects performed dynamic knee extensor (KE) and elbow flexors (EF) exercise.
View Article and Find Full Text PDFMaximal oxygen (O ) uptake ( ) is an important parameter with utility in health and disease. However, the relative importance of O transport and utilization capacities in limiting muscle before and after endurance exercise training is not well understood. Therefore, the present study aimed to identify the mechanisms determining muscle pre- and post-endurance exercise training in initially sedentary participants.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
January 2024
Lifestyle modification including exercise training is often the first line of defense in the treatment of obesity and hypertension (HTN), however, little is known regarding how these potentially compounding disease states impact vasodilatory and hemodynamic responses at baseline and exercise. Therefore, this study sought to compare the impact of obesity on vascular function and hemodynamics at baseline and during handgrip (HG) exercise among individuals with HTN. Non-obese (13M/7F, 56 ± 16 yr, 25 ± 4 kg/m) and obese (17M/4F, 50 ± 7 yr, 35 ± 4 kg/m) middle-aged individuals with HTN forwent antihypertensive medication use for ≥2 wk before assessment of vascular function by brachial artery flow-mediated dilation (FMD) and exercise hemodynamics during progressive HG exercise at 15-30-45% maximal voluntary contraction (MVC).
View Article and Find Full Text PDFIn the peripheral and cerebral vasculature, the impact of aging and sex on the endothelial-independent functional capacity of vascular smooth muscle cells (VSMCs) is not well understood, nor is it known whether such VSMC functions in these vascular beds reflect one another. Therefore, endothelium-independent dilation, at both the conduit (Δ diameter) and microvascular (Δ vascular conductance, VC) level, elicited by sublingual nitroglycerin (NTG, 0.8 mg of Nitrostat), compared with sham-delivery (control), was assessed using Doppler ultrasound in the popliteal (PA) and middle cerebral (MCA) artery of 20 young [23 ± 4 yr, 10 males (YM)/10 females (YF)] and 21 old [69 ± 5 yr, 11 males (OM)/10 females (OF)] relatively healthy adults.
View Article and Find Full Text PDFThe age-related increase in α-adrenergic tone may contribute to decreased leg vascular conductance (LVC) both at rest and during exercise in the old. However, the effect on passive leg movement (PLM)-induced LVC, a measure of vascular function, which is markedly attenuated in this population, is unknown. Thus, in eight young (25 ± 5 yr) and seven old (65 ± 7 yr) subjects, this investigation examined the impact of systemic β-adrenergic blockade (propanalol, PROP) alone, and PROP combined with either α-adrenergic stimulation (phenylephrine, PE) or α-adrenergic inhibition (phentolamine, PHEN), on PLM-induced vasodilation.
View Article and Find Full Text PDFThe mechanisms underlying muscle dysfunction with Chronic Obstructive Pulmonary Disease (COPD) are poorly understood. Indirect evidence has recently suggested a role of Advanced Glycation End Products (AGEs) and their receptor (RAGE) in the pathophysiology of COPD. Accordingly, this study aimed to examine the redox balance and mitochondrial alterations in the skeletal muscle of a mouse model deficient in the receptor for AGE (RAGE-KO) and wild-type C57BL/6 exposed to cigarette smoke for 8-months using immunoblotting, spectrophotometry, and high-resolution respirometry.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
November 2022
An exaggerated mean arterial blood pressure (MAP) response to exercise in patients with peripheral artery disease (PAD), likely driven by inflammation and oxidative stress and, perhaps, required to achieve an adequate blood flow response, is well described. However, the blood flow response to exercise in patients with PAD actually remains equivocal. Therefore, eight patients with PAD and eight healthy controls completed 3 min of plantar flexion exercise at both an absolute work rate (WR) (2.
View Article and Find Full Text PDFJ Appl Physiol (1985)
August 2022
Exaggerated blood pressure and diminished limb hemodynamics during exercise in patients with hypertension often are not resolved by antihypertensive medications. We hypothesized that, independent of antihypertensive medication status, dietary nitrate supplementation would increase limb blood flow, decrease mean arterial pressure (MAP), and increase limb vascular conductance during exercise in patients with hypertension. Patients with hypertension either abstained from ( = 14, Off-Meds) or continued ( = 12, On-Meds) antihypertensive medications.
View Article and Find Full Text PDFBackground: Vascular dysfunction, an independent risk factor for cardiovascular disease, often persists in patients with hypertension, despite improvements in blood pressure control induced by antihypertensive medications.
Methods: As some of these medications may directly affect vascular function, this study sought to comprehensively examine the impact of reducing blood pressure, by a nonpharmacological approach (5 days of sodium restriction), on vascular function in 22 hypertensive individuals (14 men/8 women, 50 ± 10 years). Following a 2-week withdrawal of antihypertensive medications, two 5-day dietary phases, liberal sodium (liberal sodium, 200 mmol/day) followed by restricted sodium (restricted sodium, 10 mmol/day), were completed.
Aim: The importance of endothelial cell (EC) autophagy to vascular homeostasis in the context of health and disease is evolving. Earlier, we reported that intact EC autophagy is requisite to maintain shear-stress-induced nitric oxide (NO) generation via glycolysis-dependent purinergic signalling to endothelial NO synthase (eNOS). Here, we illustrate the translational and functional significance of these findings.
View Article and Find Full Text PDFNew Findings: What is the central question of this study? Use of the passive leg movement (PLM) test, a non-invasive assessment of microvascular function, is on the rise. However, PLM reliability in men has not been adequately investigated, nor has such reliability data, in men, been compared to the most commonly employed vascular function assessment, flow-mediated vasodilation (FMD). What is the main finding and its importance? PLM is a reliable method to assess vascular function in men, and is comparable to values previously reported for PLM in women, and for FMD.
View Article and Find Full Text PDFThe role of nitric oxide (NO) as a modulator of functional sympatholysis has been debated in the literature, but the preponderance of evidence suggests that the magnitude of NO-mediated dilation is restrained by sympathetic vasoconstriction. Therefore, we hypothesized that passive leg movement (PLM)-induced vasodilation, which is predominantly NO-mediated, would be attenuated by an exercise-induced increase in muscle sympathetic nerve activity (MSNA). To test this hypothesis, MSNA, leg blood flow (LBF), and mean arterial blood pressure (MAP) were measured and leg vascular conductance (LVC) calculated in 9 healthy subjects (30 ± 3 yr), during PLM with and without sympathoexcitation evoked by arm-cranking exercise (ACE), at 25, 50, and 75% of maximal capacity.
View Article and Find Full Text PDFCardiovasomobility is a novel concept that encompasses the integration of cardiovascular and skeletal muscle function in health and disease with critical modification by physical activity, or lack thereof. Compelling evidence indicates that physical activity improves health while a sedentary, or inactive, lifestyle accelerates cardiovascular and skeletal muscle dysfunction and hastens disease progression. Identifying causative factors for vascular and skeletal muscle dysfunction, especially in humans, has proven difficult due to the limitations associated with cross-sectional investigations.
View Article and Find Full Text PDFThis study investigated the impact of dietary nitrate supplementation on peripheral hemodynamics, the development of neuromuscular fatigue, and time to task failure during cycling exercise. Eleven recreationally active male participants (27 ± 5 yr, V̇o: 42 ± 2 mL/kg/min) performed two experimental trials following 3 days of either dietary nitrate-rich beetroot juice (4.1 mmol NO/day; DNS) or placebo (PLA) supplementation in a blinded, counterbalanced order.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
November 2021
Recently it was documented that fatiguing, high-intensity exercise resulted in a significant attenuation in maximal skeletal muscle mitochondrial respiratory capacity, potentially due to the intramuscular metabolic perturbation elicited by such intense exercise. With the utilization of intrathecal fentanyl to attenuate afferent feedback from group III/IV muscle afferents, permitting increased muscle activation and greater intramuscular metabolic disturbance, this study aimed to better elucidate the role of metabolic perturbation on mitochondrial respiratory function. Eight young, healthy males performed high-intensity cycle exercise in control (CTRL) and fentanyl-treated (FENT) conditions.
View Article and Find Full Text PDFNew Findings: What is the central question of this study? The passive leg movement (PLM) assessment of vascular function utilizes the blood flow response in the common femoral artery (CFA): what is the impact of baseline CFA blood flow on the PLM response? What is the main finding and its importance? Although an attenuated PLM response is not an obligatory consequence of increased baseline CFA blood flow, increased blood flow through the deep femoral artery will diminish the response. Care should be taken to ensure that a genuine baseline leg blood flow is obtained prior to performing a PLM vascular function assessment.
Abstract: The passive leg movement (PLM) assessment of vascular function utilizes the blood flow response in the common femoral artery (CFA).
Chronic sympathetic nervous system (SNS) overactivity, characteristic of heart failure (HF) with reduced ejection fraction (HFrEF), is associated with poor prognosis and contributes to increased mortality risk. Sacubitril-valsartan is a recently approved, first-in-class, angiotensin receptor neprilysin inhibitor (ARNI) drug that markedly reduces the risks of death from cardiovascular causes and hospitalization for HF in patients with HFrEF, but the physiological mechanisms underlying these benefits are not fully understood. This single-arm, open-label, prospective study sought to test the hypothesis that short-term treatment with sacubitril-valsartan reduces SNS activity, measured directly via muscle sympathetic nerve activity (MSNA), in patients with HFrEF.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
July 2021
Because patients with chronic obstructive pulmonary disease (COPD) are often physically inactive, it is still unclear whether the lower respiratory capacity in the locomotor muscles of these patients is due to cigarette smoking per se or is secondary to physical deconditioning. Accordingly, the purpose of this study was to examine mitochondrial alterations in the quadriceps muscle of 10 mice exposed to 8 mo of cigarette smoke, a sedentary mouse model of emphysema, and 9 control mice, using immunoblotting, spectrophotometry, and high-resolution respirometry in permeabilized muscle fibers. Mice exposed to smoke displayed a twofold increase in the oxidative stress marker, 4-HNE, ( < 0.
View Article and Find Full Text PDF