scholarly journals Ascorbic acid improves brachial artery vasodilation during progressive handgrip exercise in the elderly through a nitric oxide-mediated mechanism

2016 ◽  
Vol 310 (6) ◽  
pp. H765-H774 ◽  
Author(s):  
Joel D. Trinity ◽  
D. Walter Wray ◽  
Melissa A. H. Witman ◽  
Gwenael Layec ◽  
Zachary Barrett-O'Keefe ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Brachial Artery ◽  
Vascular Function ◽  
The Elderly ◽  
Voluntary Contraction ◽  
Dependent Manner ◽  
Handgrip Exercise ◽  
Age Related

The proposed mechanistic link between the age-related attenuation in vascular function and free radicals is an attractive hypothesis; however, direct evidence of free radical attenuation and a concomitant improvement in vascular function in the elderly is lacking. Therefore, this study sought to test the hypothesis that ascorbic acid (AA), administered intra-arterially during progressive handgrip exercise, improves brachial artery (BA) vasodilation in a nitric oxide (NO)-dependent manner, by mitigating free radical production. BA vasodilation (Doppler ultrasound) and free radical outflow [electron paramagnetic resonance (EPR) spectroscopy] were measured in seven healthy older adults (69 ± 2 yr) during handgrip exercise at 3, 6, 9, and 12 kg (∼13–52% of maximal voluntary contraction) during the control condition and nitric oxide synthase (NOS) inhibition via NG-monomethyl-l-arginine (l-NMMA), AA, and coinfusion of l-NMMA + AA. Baseline BA diameter was not altered by any of the treatments, while l-NMMA and l-NMMA + AA diminished baseline BA blood flow and shear rate. AA improved BA dilation compared with control at 9 kg (control: 6.5 ± 2.2%, AA: 10.9 ± 2.5%, P = 0.01) and 12 kg (control: 9.5 ± 2.7%, AA: 15.9 ± 3.7%, P < 0.01). NOS inhibition blunted BA vasodilation compared with control and when combined with AA eliminated the AA-induced improvement in BA vasodilation. Free radical outflow increased with exercise intensity but, interestingly, was not attenuated by AA. Collectively, these results indicate that AA improves BA vasodilation in the elderly during handgrip exercise through an NO-dependent mechanism; however, this improvement appears not to be the direct consequence of attenuated free radical outflow from the forearm.

scholarly journals Exercise-induced brachial artery vasodilation: effects of antioxidants and exercise training in elderly men

2010 ◽  
Vol 298 (2) ◽  
pp. H671-H678 ◽  
Author(s):  
Anthony J. Donato ◽  
Abhimanyu Uberoi ◽  
Damian M. Bailey ◽  
D. Walter Wray ◽  
Russell S. Richardson
Keyword(s):  
Exercise Training ◽  
Brachial Artery ◽  
Vascular Function ◽  
Knee Extensor ◽  
The Elderly ◽  
Young Group ◽  
Handgrip Exercise ◽  
Age Related ◽  
Young Subjects ◽  
Exercise Induced

Aging, vascular function, and exercise are thought to have a common link in oxidative stress. Of the 28 subjects studied (young, 26 ± 2 yr; old, 71 ± 6 yr), 12 took part in a study to validate an antioxidant cocktail (AOC: vitamins C, E, and α-lipoic acid), while the remaining 8 young and 8 old subjects performed submaximal forearm handgrip exercise with placebo or AOC. Old subjects repeated forearm exercise with placebo or AOC following knee-extensor (KE) exercise training. Brachial arterial diameter and blood velocity (Doppler ultrasound) were measured at rest and during exercise. During handgrip exercise, brachial artery vasodilation in the old subjects was attenuated compared with that in young subjects following placebo (maximum = ∼3.0 and ∼6.0%, respectively). In contrast to the previously documented attenuation in exercise-induced brachial artery vasodilation in the young group with AOC, in the old subjects the AOC restored vasodilation (maximum = ∼7.0%) to match the young. KE training also improved exercise-induced brachial artery vasodilation. However, in the trained state, AOC administration no longer augmented brachial artery vasodilation in the elderly, but rather attenuated it. These data reveal an age-related pro-/antioxidant imbalance that impacts vascular function and show that exercise training is capable of restoring equilibrium such that vascular function is improved and the AOC-mediated reduction in free radicals now negatively impacts brachial artery vasodilation, as seen in the young.

scholarly journals Contribution of nitric oxide to brachial artery vasodilation during progressive handgrip exercise in the elderly

2013 ◽  
Vol 305 (8) ◽  
pp. R893-R899 ◽  
Author(s):  
Joel D. Trinity ◽  
D. Walter Wray ◽  
Melissa A. H. Witman ◽  
Gwenael Layec ◽  
Zachary Barrett-O'Keefe ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Shear Rate ◽  
Brachial Artery ◽  
Vascular Function ◽  
The Elderly ◽  
Flow Mediated Dilation ◽  
Handgrip Exercise ◽  
Modest Contribution ◽  
Older Subjects ◽  
The Relationship

The reduction in nitric oxide (NO)-mediated vascular function with age has largely been determined by flow-mediated dilation (FMD). However, in light of recent uncertainty surrounding the NO dependency of FMD and the recognition that brachial artery (BA) vasodilation during handgrip exercise is predominantly NO-mediated in the young, we sought to determine the contribution of NO to BA vasodilation in the elderly using the handgrip paradigm. BA vasodilation during progressive dynamic (1 Hz) handgrip exercise performed at 3, 6, 9, and 12 kg was assessed with and without NO synthase (NOS) inhibition [intra-arterial NG-monomethyl-l-arginine (l-NMMA)] in seven healthy older subjects (69 ± 2 yr). Handgrip exercise in the control condition evoked significant BA vasodilation at 6 (4.7 ± 1.4%), 9 (6.5 ± 2.2%), and 12 kg (9.5 ± 2.7%). NOS inhibition attenuated BA vasodilation, as the first measurable increase in BA diameter did not occur until 9 kg (4.0 ± 1.8%), and the change in BA diameter at 12 kg was reduced by ∼30% (5.1 ± 2.2%), with unaltered shear rate (Control: 407 ± 57, l-NMMA: 427 ± 67 s−1). Although shifted downward, the slope of the relationship between BA diameter and shear rate during handgrip exercise was unchanged (Control: 0.0013 ± 0.0004, l-NMMA: 0.0011 ± 0.007, P = 0.6) as a consequence of NOS inhibition. Thus, progressive handgrip exercise in the elderly evokes a robust BA vasodilation, the magnitude of which was only minimally attenuated following NOS inhibition. This modest contribution of NO to BA vasodilation in the elderly supports the use of the handgrip exercise paradigm to assess NO-dependent vasodilation across the life span.

Arterial properties along the upper arm in humans: age-related effects and the consequence of anatomical location

2010 ◽  
Vol 108 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Niclas Bjarnegård ◽  
Toste Länne
Keyword(s):  
Brachial Artery ◽  
Vascular Function ◽  
Intima Media Thickness ◽  
Proximal Part ◽  
The Elderly ◽  
Elderly Subjects ◽  
Anatomical Location ◽  
Upper Arm ◽  
Age Related ◽  
Proximal Site

The normal aging process of the brachial artery (BA) wall is of specific interest since it is often selected as a model artery in studies of vascular function. With echo-tracking ultrasound, diameter, absolute diameter change, and intima-media thickness (IMT) were registered in 60 healthy subjects, 21–86 yr (30 men), at a proximal, upper third, and distal arterial site along the upper arm. Blood pressure was recorded noninvasively, and the distensibility coefficient (DC) was calculated. The diameter at the proximal site increased with age from 5.5 ± 0.2 mm in the young subjects to 6.9 ± 0.3 mm ( P < 0.01) in the elderly subjects, concomitantly as IMT increased from 0.40 ± 0.01 to 0.65 ± 0.03 mm ( P < 0.001). The diameter at the other sites was similar in the young and elderly subjects, whereas IMT increased slightly with age. At the proximal site, DC decreased dramatically from 40.7 ± 2.2 to 10.1 ± 0.8 10−3/kPa ( P < 0.001) with age, whereas hardly no change was seen in the distal upper arm. The principal transit zone between elastic to predominantly muscular artery behavior seems to be located within the proximal part of the brachial artery, emphasizing the importance of carefully defining the arterial examination site.

Vagal modulation of the heart and central hemodynamics during handgrip exercise

2000 ◽  
Vol 278 (5) ◽  
pp. H1648-H1652 ◽  
Author(s):  
Heidi A. Kluess ◽  
Robert H. Wood ◽  
Michael A. Welsch
Keyword(s):  
Coefficient Of Variation ◽  
Spontaneous Breathing ◽  
Repeated Measures ◽  
Voluntary Contraction ◽  
Dependent Manner ◽  
Handgrip Exercise ◽  
Low Intensity ◽  
Vagal Modulation ◽  
The Mean ◽  
Low Intensity Exercise

Blood pressure and continuous electrocardiogram recordings were obtained from 12 participants during spontaneous breathing (SB1), dynamic handgrip exercise at 20% (HG20) of maximal voluntary contraction (MVC), and spontaneous breathing (SB2) and dynamic handgrip exercise at 60% (HG60) of MVC. Repeated-measures ANOVAs were used to examine the effects of the exercise conditions on mean arterial pressure (MAP), on mean standard deviation (SDNN), and on the coefficient of variation of R-R intervals. The mean R-R interval responded to exercise in an intensity-dependent manner. SDNN decreased with exercise but was not intensity dependent. Coefficient of variation decreased during HG20, and MAP increased following HG60. These data are consistent with the notion that changes in cardiovascular function with low-intensity exercise are primarily mediated by parasympathetic withdrawal, and as exercise intensity increases, additional cardiovascular reactivity is mediated by increased sympathetic outflow. The change in the coefficient of variation from rest to exercise was unique in comparison to the changes in SDNN, and this merits further investigation.

Impairment of vascular function is associated with an age-related increase of lipid peroxidation in rats

1996 ◽  
Vol 271 (6) ◽  
pp. R1625-R1631 ◽  
Author(s):  
S. T. Davidge ◽  
C. A. Hubel ◽  
M. K. McLaughlin
Keyword(s):  
Nitric Oxide ◽  
Lipid Peroxidation ◽  
Vascular Function ◽  
Mesenteric Arteries ◽  
Relaxation Response ◽  
Female Rat ◽  
Cyclooxygenase Inhibition ◽  
Age Related ◽  
Old Rats ◽  
Over Time

We tested the hypothesis that an increase in endogenous lipid peroxidation over time is associated with an impairment of endothelium-dependent vascular function in resistance-sized mesenteric arteries that is due in part to alterations of arachidonate metabolism. Susceptibility to red blood cell hemolysis and sera levels of malondialdehyde were increased (P < 0.05) from 20 wk (n = 12) to 40 wk (n = 12) in female Sprague-Dawley rats. Arteries were studied in a myograph by examining the endothelial modification of phenylephrine vasoconstriction and the relaxation responses of the mesenteric arteries to methacholine. We observed the following. 1) An increase in sensitivity to alpha 1-adrenergic stimulation occurred between 20 and 40 wk of age. Cyclooxygenase inhibition decreased the sensitivity to phenylephrine only in the arteries from the 40-wk-old rats, indicating that a cyclooxygenase-dependent vasoconstrictor was modifying the phenylephrine response. 2) Nitric oxide synthase inhibition caused a greater increase in phenylephrine sensitivity in the arteries from the 20-wk-old rats than those from the 40-wk-old rats, indicating that nitric oxide modification of phenylephrine sensitivity decreased with age. 3) Endothelium-independent relaxations were not affected between 20 and 40 wk of age. 4) At 40 wk, the sensitivity to the methacholine-mediated relaxation response decreased without impairing the maximal relaxation response. This reduced sensitivity was removed with cyclooxygenase inhibition or thromboxane A2/prostaglandin H2 (PGH2) receptor blockade. 5) Aortas from the 40-wk-old rats had an increased expression of PGH synthase. Collectively, these observations indicate that, in the female rat, an increase in lipid peroxidation over time is associated with changes in endothelium-dependent vascular function that were due in part to a cyclooxygenase-dependent vasoconstrictor.

scholarly journals Age-Associated Changes in the Spectral and Statistical Parameters of Surface Electromyogram ofTibialis Anterior

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ariba Siddiqi ◽  
Sridhar Poosapadi Arjunan ◽  
Dinesh Kant Kumar
Keyword(s):  
Muscle Strength ◽  
Tibialis Anterior ◽  
The Elderly ◽  
Voluntary Contraction ◽  
Maximal Power ◽  
Statistical Parameters ◽  
Surface Electromyogram ◽  
Age Related ◽  
Power Spectral ◽  
Different Levels

Age-related neuromuscular change of Tibialis Anterior (TA) is a leading cause of muscle strength decline among the elderly. This study has established the baseline for age-associated changes in sEMG of TA at different levels of voluntary contraction. We have investigated the use of Gaussianity and maximal power of the power spectral density (PSD) as suitable features to identify age-associated changes in the surface electromyogram (sEMG). Eighteen younger (20–30 years) and 18 older (60–85 years) cohorts completed two trials of isometric dorsiflexion at four different force levels between 10% and 50% of the maximal voluntary contraction. Gaussianity and maximal power of the PSD of sEMG were determined. Results show a significant increase in sEMG’s maximal power of the PSD and Gaussianity with increase in force for both cohorts. It was also observed that older cohorts had higher maximal power of the PSD and lower Gaussianity. These age-related differences observed in the PSD and Gaussianity could be due to motor unit remodelling. This can be useful for noninvasive tracking of age-associated neuromuscular changes.

scholarly journals EVALUATION OF FREE RADICAL SCAVENGING ACTIVITY OF MIMOSA PUDICA THORNS

2018 ◽  
Vol 11 (11) ◽  
pp. 153 ◽  
Author(s):  
Lakshmibai R ◽  
Amirtham D
Keyword(s):  
Nitric Oxide ◽  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Free Radical Scavenging Activity ◽  
Scavenging Activity ◽  
Mimosa Pudica ◽  
Age Related ◽  
Dpph Method

Objective: Mimosa pudica is a traditional medicinal plant. The natural antioxidant compounds from plants mop up the free radicals causing cell damage and maintain the biological systems. The aim of the present study is to evaluate the free radical scavenging potential of the ethanolic and aqueous thorn extracts of M. pudica.Methods: The ethanolic and aqueous thorn extracts of M. pudica were analyzed for the phytochemicals and for free radical scavenging activity by 1, 1 diphenyl 1-2-picric hydrazine (DPPH), 2, 2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and nitric oxide free radical scavenging method.Results: Flavonoids, saponins, glycosides, alkaloids, terpenoids, and coumarins were the phytoconstituents revealed in ethanolic and aqueous thorn extracts of M. pudica. At 250 μg/mL concentrations, aqueous thorn extracts of M. pudica exhibited 73.41% radical scavenging activity by DPPH method and 26.10% inhibition by nitric oxide free radical scavenging method. However, the ethanolic extracts of M. pudica thorns exhibited 73.35% inhibition by ABTS free radical scavenging method at 250 μg/mL concentrations.Conclusion: The results obtained suggest that the plant extracts from M. pudica could serve as a potential source of antioxidant in slowing down the process of aging and age-related or oxidative stress-related degenerative diseases. Moreover, the isolation of bioactive principle responsible for the antioxidant activity and formulation of novel therapeutic agents can be further studied.

scholarly journals Sodium nitrite and ascorbic acid: a metal-free combination that controls the free-radical polymerization of tert-butyl methacrylate in water

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Christophe Detrembleur ◽  
Ange Mouithys-Mickalad ◽  
Philippe Teyssié ◽  
Robert Jérôme
Keyword(s):  
Nitric Oxide ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Radical Polymerization ◽  
Sodium Nitrite ◽  
Free Radical Polymerization ◽  
Nitroxyl Radicals ◽  
Butyl Methacrylate ◽  
Metal Free ◽  
Tert Butyl

AbstractA mixture of sodium nitrite and ascorbic acid is able to control the radical polymerization of tert-butyl methacrylate (tBMA) in water at 80°C. Indeed, sodium nitrite is reduced by the ascorbic acid, and the nitric oxide (NO) which is formed insitu is nothing but a promoter of nitroxyl radicals. The radical polymerization of tBMA is thus basically controlled by a nitroxide-mediated process.

Persistence of EDHF pathway and impairment of the nitric oxide pathway after chronic mercury chloride exposure in rats: Mechanisms of endothelial dysfunction

2010 ◽  
Vol 30 (11) ◽  
pp. 1777-1784 ◽  
Author(s):  
S Omanwar ◽  
K Ravi ◽  
M Fahim
Keyword(s):  
Nitric Oxide ◽  
Endothelial Dysfunction ◽  
Vascular Function ◽  
Rat Aorta ◽  
Mercury Exposure ◽  
Mercury Chloride ◽  
Dependent Manner ◽  
Selective Loss ◽  
Dose Dependent ◽  
Endothelium Dependent Relaxation

Chronic mercury exposure impairs vascular function, leading to the depression of endothelium-dependent vasodilatation. Loss of the nitric oxide (NO) pathway has been implicated, but little is known about effects on other endothelial mediators. This study investigated the mechanisms of endothelial dysfunction in rats subjected to chronic mercury chloride exposure. The endothelium-dependent relaxation of rat aorta evoked by acetylcholine (ACh) and isoproterenol was impaired in a dose-dependent manner by chronic mercury chloride exposure. Endothelium-independent responses to sodium nitroprusside (SNP) were not affected by chronic mercury chloride exposure. In healthy vessels, ACh-induced relaxation was inhibited by L-N-nitroarginine methyl ester (L-NAME; 10–4M) and partially by glybenclamide (10–5M), indicating the involvement of NO and endothelium-derived hyperpolarizing factor (EDHF). In vessels from mercury-exposed rats, responses to ACh were insensitive to L-NAME but were significantly reduced by glybenclamide, indicating selective loss of NO-mediated relaxation. In vessels from mercury-exposed rats, responses to ACh were partially restored after treatment with the antioxidant, superoxide dismutase (SOD) and catalase, this effect was not seen when aorta from exposed group was incubated with L-NAME along with SOD and catalase indicating selective loss of NO-mediated vasodilatation and with no affect the EDHF-mediated component of relaxation. The results imply that chronic mercury exposure selectively impairs the NO pathway as a consequence of oxidative stress, while EDHF is able to maintain endothelium-dependent relaxation at a reduced level.

scholarly journals Comparative Antioxidant Potential of Different Extracts of Celastrus paniculatus Willd. Seed

1970 ◽  
Vol 3 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Fatema Tuz Zohera ◽  
Md Razibul Habib ◽  
Mohammad Zafar Imam ◽  
Md Ehsanul Hoque Mazumder ◽  
Md Sohel Rana
Keyword(s):  
Nitric Oxide ◽  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Ethyl Acetate ◽  
Ethyl Acetate Extract ◽  
Reducing Power ◽  
Antioxidant Potential ◽  
Dependent Manner ◽  
Ic50 Value ◽  
Celastrus Paniculatus

The objective of the present study was to evaluate the comparative antioxidant potential of methanol, ethyl acetate, pet ether and water extracts of Celastrus paniculatus seed. Antioxidant activity was evaluated by using total phenol and flavonoid content determination assays, total antioxidant capacity, 1,1-diphenyl-2- picryl-hydrazil (DPPH) free radical assay, Reducing power assessment, Nitric oxide (NO) scavenging assay and Cupric ion reducing capacity assay (CUPRAC method). The extracts showed moderate antioxidant activity in a dose dependent manner. The extracts were found to contain phenolics and flavonoid compounds. In DPPH radical scavenging assay, ethyl acetate extract had the lowest IC50 value (585.58μg/ml) compared to ascorbic acid. In nitric oxide scavenging assay IC50 value was found to be 122.99μg/ml, 320.54μg/ml, 601.81μg/ml and 206.37μg/ml respectively for the Water, Methanol, Ethyl Acetate and Pet Ether extracts compared to 6.83μg/ml which was the IC50 value for the reference ascorbic acid. The extracts also showed good reducing power. The results of the present study indicate that the extracts possesses significant antioxidant potential of which ethyl acetate extract is the most promising one and possess highest antioxidant potential. Key Words: Celastrus paniculatus; antioxidant; DPPH; NO scavenging; CUPRAC; ROS. DOI: 10.3329/sjps.v3i1.6802S. J. Pharm. Sci. 3(1): 68-74

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