Angiotensin II potentiates α-adrenergic vasoconstriction in the elderly

2012 ◽  
Vol 124 (6) ◽  
pp. 413-422 ◽  
Author(s):  
Zachary Barrett-O’Keefe ◽  
Melissa A. H. Witman ◽  
John Mcdaniel ◽  
Anette S. Fjeldstad ◽  
Joel D. Trinity ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cross Talk ◽  
Healthy Aging ◽  
The Elderly ◽  
Young Group ◽  
Adrenergic Blockade ◽  
Arterial Blood ◽  
Nervous System Activity ◽  
Half Maximal Effective Concentration ◽  
Adrenergic Systems

Aging is characterized by increased sympatho-excitation, expressed through both the α-adrenergic and RAAS (renin–angiotensin–aldosterone) pathways. Although the independent contribution of these two pathways to elevated vasoconstriction with age may be substantial, significant cross-talk exists that could produce potentiating effects. To examine this interaction, 14 subjects (n=8 young, n=6 old) underwent brachial artery catheterization for administration of AngII (angiotensin II; 0.8–25.6 ng/dl per min), NE [noradrenaline (norepinephrine); 2.5–80 ng/dl per min] and AngII with concomitant α-adrenergic antagonism [PHEN (phentolamine); 10 μg/dl per min]. Ultrasound Doppler was utilized to determine blood flow, and therefore vasoconstriction, in both infused and contralateral (control) limbs. Arterial blood pressure was measured directly, and sympathetic nervous system activity was assessed via microneurography and plasma NE analysis. AngII sensitivity was significantly greater in the old, indicated by both greater maximal vasoconstriction (−59±4% in old against −48±3% in young) and a decreased EC50 (half-maximal effective concentration) (1.4±0.2 ng/dl per min in old against 2.6±0.7 μg/dl per min in young), whereas the maximal NE-mediated vasoconstriction was similar between these groups (−58±9% in old and −62±5% in young). AngII also increased venous NE in the old group, but was unchanged in the young group. In the presence of α-adrenergic blockade (PHEN), maximal AngII-mediated vasoconstriction in the old was restored to that of the young (−43±8% in old and −39±6% in young). These findings indicate that, with healthy aging, the increased AngII-mediated vasoconstriction may be attributed, in part, to potentiation of the α-adrenergic pathway, and suggest that cross-talk between the RAAS and adrenergic systems may be an important consideration in therapeutic strategies targeting these two pathways.

scholarly journals Aging augments renal vasoconstrictor response to orthostatic stress in humans

2015 ◽  
Vol 309 (12) ◽  
pp. R1474-R1478 ◽  
Author(s):  
Christine M. Clark ◽  
Kevin D. Monahan ◽  
Rachel C. Drew
Keyword(s):  
Blood Flow ◽  
Healthy Aging ◽  
Lower Body Negative Pressure ◽  
Systemic Circulation ◽  
Young Group ◽  
Orthostatic Stress ◽  
Renal Vasoconstriction ◽  
Arterial Blood ◽  
Vasoconstrictor Response ◽  
Renal Vascular

The ability of the human body to maintain arterial blood pressure (BP) during orthostatic stress is determined by several reflex neural mechanisms. Renal vasoconstriction progressively increases during graded elevations in lower body negative pressure (LBNP). This sympathetically mediated response redistributes blood flow to the systemic circulation to maintain BP. However, how healthy aging affects the renal vasoconstrictor response to LBNP is unknown. Therefore, 10 young (25 ± 1 yr; means ± SE) and 10 older (66 ± 2 yr) subjects underwent graded LBNP (−15 and −30 mmHg) while beat-to-beat renal blood flow velocity (RBFV; Doppler ultrasound), arterial BP (Finometer), and heart rate (HR; electrocardiogram) were recorded. Renal vascular resistance (RVR), an index of renal vasoconstriction, was calculated as mean BP/RBFV. All baseline cardiovascular variables were similar between groups, except diastolic BP was higher in older subjects ( P < 0.05). Increases in RVR during LBNP were greater in the older group compared with the young group (older: −15 mmHg Δ10 ± 3%, −30 mmHg Δ20 ± 5%; young: −15 mmHg Δ2 ± 2%, −30 mmHg Δ6 ± 2%; P < 0.05). RBFV tended to decrease more ( P = 0.10) and mean BP tended to decrease less ( P = 0.09) during LBNP in the older group compared with the young group. Systolic and diastolic BP, pulse pressure, and HR responses to LBNP were similar between groups. These findings suggest that aging augments the renal vasoconstrictor response to orthostatic stress in humans.

scholarly journals Gait Analysis under Spatial Navigation Task in Elderly People—A Pilot Study

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 270
Author(s):  
Natalia Pawlaczyk ◽  
Magdalena Szmytke ◽  
Michał Meina ◽  
Monika Lewandowska ◽  
Justyna Stępniak ◽  
...  
Keyword(s):  
Healthy Aging ◽  
Spatial Navigation ◽  
The Elderly ◽  
Young Group ◽  
Operating Characteristics ◽  
Important Indicator ◽  
Gait Parameters ◽  
Memory Phase ◽  
The Difference ◽  
Delayed Phase

A decline in the Spatial Navigation (SN) abilities has been observed in the course of healthy aging. Walking is an inseparable part of the navigation process; however, research tasks overlook this aspect in studies involving seniors. The present study was designed to overcome this limitation by recording gait parameters during natural environment navigation and to determine gait indicators that most accurately assign the participants to the proper age category. Thirteen elderly (mean age = 69.1 ± 5.4 year) and sixteen young women (mean age = 21.5 ± 2.2 year) equipped with gait sensors were asked to learn a path while walking in a real building (Learning Phase), reproduce the path (Memory Phase) and reach targets after a 30 min delay (Delayed Phase). The Receiver Operating Characteristics (ROC) analysis showed that our self-developed Gait Style Change indicator, that is, the difference in the probability of feet landing between particular SN task phases, classified the participants into either the elderly or the young group with the highest accuracy (0.91). The second most important indicator, the Task-Related (step counts in each SN task phase), achieved the accuracy discrimination of 0.83. The gait indicators, comprising single gait parameters measured while navigating, might be considered as accurately differentiating older from younger people.

Nonadrenergic noncholinergic autonomic mediation of pressor response to feeding in lambs

1993 ◽  
Vol 265 (3) ◽  
pp. R530-R536 ◽  
Author(s):  
S. A. Jones ◽  
B. L. Langille ◽  
S. Frise ◽  
S. L. Adamson
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Angiotensin Ii ◽  
Pressor Response ◽  
Adrenergic Blockade ◽  
Arterial Blood ◽  
Plasma Angiotensin ◽  
Muscarinic Cholinergic ◽  
Alpha Beta

We examined factors mediating a 70% increase in arterial blood pressure that occurs during feeding in newborn lambs. We report that the increase in blood pressure during feeding was significantly reduced (to approximately 50%) and delayed in onset by combined alpha- and beta-adrenergic blockade. Plasma angiotensin and vasopressin levels did not increase significantly during feeding, nor was the pressor response to feeding attenuated while using captopril to block the production of angiotensin II. Adrenalectomy or muscarinic cholinergic blockade with atropine was also unsuccessful in attenuating the pressor response to feeding. We demonstrated that the component of the pressor response to feeding that was insensitive to alpha, beta, and muscarinic blockade was mediated by the autonomic nervous system because it was completely eliminated by ganglionic blockade with hexamethonium. Thus nonadrenergic noncholinergic autonomic mechanisms mediate approximately half the pressor response to feeding in lambs.

scholarly journals Extra- and intracranial blood flow regulation during the cold pressor test: influence of age

2017 ◽  
Vol 123 (5) ◽  
pp. 1071-1080 ◽  
Author(s):  
Daniela Flück ◽  
Philip N. Ainslie ◽  
Anthony R. Bain ◽  
Kevin W. Wildfong ◽  
Laura E. Morris ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Cerebral Artery ◽  
Healthy Aging ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Young Group ◽  
Sympathetic Activation ◽  
Older Individuals ◽  
Pressor Test ◽  
Arterial Blood

We determined how the extra- and intracranial circulations respond to generalized sympathetic activation evoked by a cold pressor test (CPT) and whether this is affected by healthy aging. Ten young [23 ± 2 yr (means ± SD)] and nine older (66 ± 3 yr) individuals performed a 3-min CPT by immersing the left foot into 0.8 ± 0.3°C water. Common carotid artery (CCA) and internal carotid artery (ICA) diameter, velocity, and flow were simultaneously measured (duplex ultrasound) along with middle cerebral artery and posterior cerebral artery mean blood velocity (MCAvmean and PCAvmean) and cardiorespiratory variables. The increases in heart rate (~6 beats/min) and mean arterial blood pressure (~14 mmHg) were similar in young and older groups during the CPT ( P < 0.01 vs. baseline). In the young group, the CPT elicited an ~5% increase in CCA diameter ( P < 0.01 vs. baseline) and a tendency for an increase in CCA flow (~12%, P = 0.08); in contrast, both diameter and flow remained unchanged in the older group. Although ICA diameter was not changed during the CPT in either group, ICA flow increased (~8%, P = 0.02) during the first minute of the CPT in both groups. Whereas the CPT elicited an increase in MCAvmean and PCAvmean in the young group (by ~20 and ~10%, respectively, P < 0.01 vs. baseline), these intracranial velocities were unchanged in the older group. Collectively, during the CPT, these findings suggest a differential mechanism(s) of regulation between the ICA compared with the CCA in young individuals and a blunting of the CCA and intracranial responses in older individuals. NEW & NOTEWORTHY Sympathetic activation evoked by a cold pressor test elicits heterogeneous extra- and intracranial blood vessel responses in young individuals that may serve an important protective role. The extra- and intracranial responses to the cold pressor test are blunted in older individuals.

Effects of beta 1-adrenergic blockade on glomerular dynamics and angiotensin II response

1989 ◽  
Vol 257 (2) ◽  
pp. F225-F230 ◽  
Author(s):  
B. J. Tucker ◽  
C. A. Mundy ◽  
R. C. Blantz
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Adrenergic Blockade ◽  
Nephron Filtration Rate ◽  
Arterial Blood ◽  
Adrenergic Antagonist ◽  
Adrenergic Activity ◽  
Glomerular Hemodynamics

Adrenergic activity regulates renal function by several mechanisms. Renal nerves not only exert vasoconstrictor functions but also may influence glomerular hemodynamics by beta-adrenergic activity, especially via the effects on renin angiotensin activity. Little is known of the specific glomerular hemodynamic alterations resulting from beta 1-adrenergic blockade. Current studies examined the effects of 4-6 days of treatment with atenolol (50 mg/kg), a beta 1-selective adrenergic antagonist, on glomerular hemodynamics in plasma volume-expanded Munich-Wistar rats. Atenolol treatment reduced blood pressure both in the awake state and during micropuncture. This reduction in blood pressure contributed to a decrease in nephron filtration rate (48 +/- 1 in untreated rats vs. 40 +/- 1 nl.min-1.g kidney wt-1 in the atenolol-treated group, P less than 0.05) by reduction in nephron plasma flow (182 +/- 2 vs. 154 +/- 4 nl.min-1.g kidney wt-1 in the atenolol-treated rats). No other determinant of glomerular ultrafiltration was influenced by atenolol treatment. Since beta 1-adrenergic blockade may influence the generation of angiotensin II, the response to angiotensin II infusion was assessed and found not to differ from control untreated animals. These studies demonstrate that beta 1-receptor blockade reduced nephron filtration rate by decreasing mean arterial blood pressure and nephron plasma flow without significant modifications in vascular resistance and the glomerular hydrostatic pressure gradient.

Prospective Memory Development Across the Lifespan

2020 ◽  
Vol 25 (3) ◽  
pp. 162-173 ◽  
Author(s):  
Sascha Zuber ◽  
Matthias Kliegel
Keyword(s):  
Prospective Memory ◽  
Healthy Aging ◽  
Present Model ◽  
Current Knowledge ◽  
Well Being ◽  
The Elderly ◽  
Cognitive Factors ◽  
Everyday Functioning ◽  
Integrative Framework

Abstract. Prospective Memory (PM; i.e., the ability to remember to perform planned tasks) represents a key proxy of healthy aging, as it relates to older adults’ everyday functioning, autonomy, and personal well-being. The current review illustrates how PM performance develops across the lifespan and how multiple cognitive and non-cognitive factors influence this trajectory. Further, a new, integrative framework is presented, detailing how those processes interplay in retrieving and executing delayed intentions. Specifically, while most previous models have focused on memory processes, the present model focuses on the role of executive functioning in PM and its development across the lifespan. Finally, a practical outlook is presented, suggesting how the current knowledge can be applied in geriatrics and geropsychology to promote healthy aging by maintaining prospective abilities in the elderly.

Intergenerational Education for the Psychological, Social and Educational Improvement of the Elderly

2019 ◽  
Vol 15 (1) ◽  
pp. 22-26
Author(s):  
Nazaret Martínez-Heredia
Keyword(s):  
Educational Level ◽  
Mixed Type ◽  
Healthy Aging ◽  
Social Role ◽  
Intergenerational Relationships ◽  
Daily Practice ◽  
The Elderly ◽  
Educational Improvement ◽  
Intergenerational Education

Introduction: Intergenerational education encourages cooperation and interaction between two or more generations through experiences, knowledge, skills, attitudes and values. Objective: The main objective of our research was to know the benefits at the psychological, social and educational level of intergenerational education. Methods: This is mixed-type research establishing relationships between young and old. The sample consists of a total of 94 people, 47 young people (aged between 21 and 40 years old) and 47 older (aged between 65 and 85 years). We promote the development of a mixed methodology to know if after the implementation of an intergenerational program we have obtained benefits in the elderly participants. Results: Considering the results we can say that the benefits at the psychological, social and educational level have been very remarkable of our elders. Conclusions: We must bet on intergenerational relationships as an ideal within our daily practice achieving a healthy aging, benefiting continuity in an active social role of our elders.

Enhancement of the Antihypertensive Effect of Hydrochlorothiazide in Dogs after Suppression of Renin Release by Beta-Adrenergic Blockade

1975 ◽  
Vol 48 (2) ◽  
pp. 147-151
Author(s):  
C. S. Sweet ◽  
M. Mandradjieff
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Arterial Blood Pressure ◽  
Antihypertensive Effect ◽  
Plasma Renin ◽  
Renin Activity ◽  
Renin Release ◽  
Antihypertensive Activity ◽  
Adrenergic Blockade ◽  
Arterial Blood

1. Renal hypertensive dogs were treated with hydrochlorothiazide (8−2 μmol/kg or 33 μmol/kg daily for 7 days), or timolol (4.6 μmol/kg daily for 4 days), a potent β-adrenergic blocking agent, or combinations of these drugs). Changes in mean arterial blood pressure and plasma renin activity were measured over the treatment period. 2. Neither drug significantly lowered arterial blood pressure when administered alone. Plasma renin activity, which did not change during treatment with timolol, was substantially elevated during treatment with hydrochlorothiazide. 3. When timolol was administered concomitantly with hydrochlorothiazide, plasma renin activity was suppressed and blood pressure was significantly lowered. 4. These observations suggest that compensatory activation of the renin-angiotensin system limits the antihypertensive activity of hydrochlorothiazide in renal hypertensive dogs and suppression of diuretic-induced renin release by timolol unmasks the antihypertensive effect of the diuretic.

scholarly journals Endoplasmic reticulum and oxidant stress mediate nuclear factor-κB activation in the subfornical organ during angiotensin II hypertension

2015 ◽  
Vol 308 (10) ◽  
pp. C803-C812 ◽  
Author(s):  
Colin N. Young ◽  
Anfei Li ◽  
Frederick N. Dong ◽  
Julie A. Horwath ◽  
Catharine G. Clark ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Angiotensin Ii ◽  
Er Stress ◽  
Bioluminescence Imaging ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Ang Ii ◽  
Arterial Blood

Endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) generation in the brain circumventricular subfornical organ (SFO) mediate the central hypertensive actions of Angiotensin II (ANG II). However, the downstream signaling events remain unclear. Here we tested the hypothesis that angiotensin type 1a receptors (AT1aR), ER stress, and ROS induce activation of the transcription factor nuclear factor-κB (NF-κB) during ANG II-dependent hypertension. To spatiotemporally track NF-κB activity in the SFO throughout the development of ANG II-dependent hypertension, we used SFO-targeted adenoviral delivery and longitudinal bioluminescence imaging in mice. During low-dose infusion of ANG II, bioluminescence imaging revealed a prehypertensive surge in NF-κB activity in the SFO at a time point prior to a significant rise in arterial blood pressure. SFO-targeted ablation of AT1aR, inhibition of ER stress, or adenoviral scavenging of ROS in the SFO prevented the ANG II-induced increase in SFO NF-κB. These findings highlight the utility of bioluminescence imaging to longitudinally track transcription factor activation during the development of ANG II-dependent hypertension and reveal an AT1aR-, ER stress-, and ROS-dependent prehypertensive surge in NF-κB activity in the SFO. Furthermore, the increase in NF-κB activity before a rise in arterial blood pressure suggests a causal role for SFO NF-κB in the development of ANG II-dependent hypertension.

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