Abstract TP451: Age-associated Changes in the Structure and Biomechanical Properties of Parenchymal Arterioles

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Janice M Diaz-Otero ◽  
William F Jackson ◽  
Anne M Dorrance
Keyword(s):  
Blood Pressure ◽  
Extracellular Matrix ◽  
Wall Thickness ◽  
Biomechanical Properties ◽  
Wall Structure ◽  
Collagen Deposition ◽  
Artery Wall ◽  
Wall Area ◽  
Age Related ◽  
Artery Remodeling

Arterial aging, a phenomenon that we do not fully understand, results in dysfunctional arteries. Age-associated changes in physiological and vascular functions increase the risk of cardiovascular disease. Aging results in peripheral artery remodeling, described as a change in artery size and wall structure. Age-related cerebral artery remodeling could increase the risk of stroke and vascular dementia particularly in situations where comorbidities, such as hypertension, are present. The effects of aging on the biomechanical properties of parenchymal arterioles (PAs) have not been characterized. PAs regulate perfusion of the cerebral microcirculation and are important in determining cerebrovascular resistance. We hypothesized that aging would decrease the lumen diameter, and increase the wall thickness and collagen deposition in PAs from C57Bl/6 mice. PAs were collected from 3-5 month (young; n=8) and 22-24 month (old; n=8) old male mice for assessment of structure by pressure myography. Data collected at 60mmHg are presented as mean ± SEM, young vs. old. Advanced age was associated with increased systolic blood pressure (126 ± 1 vs 145 ± 2mmHg). Aging did not significantly affect the outer (49 ± 5 vs 53 ± 3μm) or lumen (41 ± 5 vs 41 ± 2μm) diameter of the PAs (p > 0.05 for all comparisons). However, the PAs from older mice had increased wall thickness (4 ± 1 vs 6 ± 1μm), wall area (591 ± 96 vs 853 ± 101μm2), and wall-to-lumen ratio (0.10 ± 0.01 vs 0.13 ± 0.01) (p < 0.05 for all comparisons). Wall stress (302 ± 27 vs 220 ± 11 dynes/cm2) was reduced with age. Changes in artery wall structure have been associated with modifications in the components of the extracellular matrix such as collagen and calcium. The PAs from older mice had increased collagen deposition in the wall (427 ± 172 vs 2699 ± 442μm2; p < 0.05) but the number of arteries with calcium deposits was similar between groups (2 ± 1 vs 3 ± 1 positive vessels/area; p > 0.05). Our studies of geriatric mice with high blood pressure suggest that aging is associated with hypertrophic remodeling of the PAs that is accompanied by alterations in the extracellular matrix of the artery wall; these changes could increase the risk of cerebrovascular diseases.

scholarly journals Relation of Plasma Coagulation Factor VII and Fibrinogen to Carotid Artery Intima-Media Thickness

1994 ◽  
Vol 72 (02) ◽  
pp. 250-254 ◽  
Author(s):  
M N Sosef ◽  
J G Bosch ◽  
J van Oostayen ◽  
T Visser ◽  
J H C Reiber ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Wall Thickness ◽  
Intima Media Thickness ◽  
Factor Vii ◽  
Clotting Factor ◽  
Multivariate Linear Regression Analysis ◽  
Artery Wall ◽  
Media Thickness ◽  
Early Atherosclerosis

SummaryPlasma clotting factor VII and plasma fibrinogen have been claimed as independent risk factors for occlusive cardiovascular disease. The aim of this study was to investigate whether these coagulation parameters affect early atherosclerosis, additional to their possible effect on arterial thrombosis.We used high-resolution quantitative ultrasonography to measure carotid intima-media thickness in 121 healthy volunteers, aged 18 to 56 years. It has previously been demonstrated that an increased artery wall thickness is seen in advanced atherosclerosis. To validate our methodology for relatively young individuals, we assessed the association of intima-media thickness with the risk-factor status of our subjects, by including classical cardiovascular risk factors, e. g. age, sex, serum cholesterol, smoking habits and blood pressure. Thereafter, we studied the effect of factor VII and fibrinogen plasma levels on carotid intimamedia thickness, as well as that of polymorphisms of the factor VII and fibrinogen genes.All classical risk factors except smoking and family history were associated with intima-media thickness. When adjusted for by multivariate linear regression analysis, age, blood pressure and cholesterol appeared to be independent determinants of intima-media thickness. Factor VII and fibrinogen levels showed no association in multivariate analysis with intima-media thickness. We conclude that artery wall thickness measurement by ultrasound is a useful tool to investigate the role of clotting factors in early atherosclerosis. Factor VII and fibrinogen levels in young and middle-aged volunteers have no association with early artherosclerotic vessel wall changes.

Negative Correlation of Wall Thickness With Wall Blood Pressure in a Patient-Specific Atherosclerotic Coronary Artery: A Case Report

2012 ◽  
Author(s):  
Biyue Liu ◽  
Jie Zheng ◽  
Richard Bach ◽  
Dalin Tang
Keyword(s):  
Blood Pressure ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Wall Thickness ◽  
Patient Specific ◽  
Artery Wall ◽  
Atherosclerosis Progression ◽  
Wall Shear ◽  
Intensive Investigation ◽  
The Impact

There are two major hemodynamic stresses imposed at the blood-arterial wall interface by flowing blood: the wall shear stress (WSS) acting tangentially to the wall, and the wall pressure (WP) acting vertically to the wall. These forces influence the artery wall metabolism and correspond to the local modifications of artery wall thickness, composition, microarchitecture, and compliance [2]. The role of flow wall shear stress in atherosclerosis progression has been under intensive investigation [4], while the impact of local blood pressure on plaque progression has been under-studied.

scholarly journals Sex and age differences in the association between sympathetic outflow and central elastic artery wall thickness in humans

2019 ◽  
Vol 317 (3) ◽  
pp. H552-H560 ◽  
Author(s):  
Seth W. Holwerda ◽  
Rachel E. Luehrs ◽  
Lyndsey E. DuBose ◽  
Rumbidzai Majee ◽  
Gary L. Pierce
Keyword(s):  
Carotid Artery ◽  
Age Differences ◽  
Young Women ◽  
Wall Thickness ◽  
Disease Risk ◽  
Cardiovascular Disease Risk ◽  
Sympathetic Outflow ◽  
Artery Wall ◽  
Carotid Imt ◽  
Age Related

Aging is characterized by increased wall thickness of the central elastic arteries (i.e., aorta and carotid arteries), although the mechanisms involved are unclear. Evidence suggests that age-related increases in muscle sympathetic nerve activity (MSNA) may be a contributing factor. However, studies in humans have been lacking. Therefore, we tested the hypothesis that age-related increases in MSNA would be independently associated with carotid artery intima-media thickness (IMT) but not in young women given the reduced influence of MSNA on the vasculature in this group. In 93 young and middle-age/older (MA/O) adults (19–73 yr, 41 women), we performed assessments of MSNA (microneurography) and common carotid IMT and lumen diameter (ultrasonography). Multiple regression that included MSNA and other cardiovascular disease risk factors indicated that MSNA ( P = 0.002) and 24-h systolic blood pressure (BP) ( P = 0.024) were independent determinants of carotid IMT-to-lumen ratio (model R2 = 0.38, P < 0.001). However, when examining only young women (<45 yr), no correlation was observed between MSNA and carotid IMT-to-lumen ratio ( R = −0.01, P = 0.963). MSNA was significantly correlated with IMT-to-lumen ratio while controlling for 24-h systolic BP among young men ( R = 0.49, P < 0.001) and MA/O women ( R = 0.59, P = 0.022). However, among MA/O men, controlling for 24-h systolic BP attenuated the association between MSNA and carotid IMT-to-lumen ratio ( R = 0.50, P = 0.115). Significant age differences in IMT-to-lumen ratio between young and MA/O men ( P = 0.047) and young and MA/O women ( P = 0.023) were removed when adjusting for MSNA (men: P = 0.970; women: P = 0.152). These findings demonstrate an association between higher sympathetic outflow and carotid artery wall thickness with a particular exception to young women. NEW & NOTEWORTHY Increased wall thickness of the large elastic arteries serves as a graded marker for cardiovascular disease risk and progression of atherosclerosis. Findings from the present study establish an independent association between higher sympathetic outflow and carotid artery wall thickness in adults with an exception to young women and extend findings from animal models that demonstrate hypertrophy of vascular smooth muscle following chronic sympathetic-adrenergic stimulation.

scholarly journals Amlodipine Improves Vessel Function and Remodeling in the Lewis Polycystic Kidney Rat Mesenteric Artery

2020 ◽  
Vol 33 (7) ◽  
pp. 634-643
Author(s):  
Ko Jin Quek ◽  
Omar Z Ameer ◽  
Jacqueline K Phillips
Keyword(s):  
Blood Pressure ◽  
Structural Parameters ◽  
Biomechanical Properties ◽  
Resistance Arteries ◽  
Polycystic Kidney ◽  
Artery Wall ◽  
Total N ◽  
Endothelium Dysfunction ◽  
Rat Mesenteric Artery ◽  
Intrinsic Stiffness

Abstract BACKGROUND Hypertension is a common comorbidity associated with chronic kidney disease (CKD). Treatment in these patients often involves L-type Ca2+ channel (LTCC) blockers. The effect of chronic LTCC-blockade treatment on resistance vasculature was investigated in a genetic hypertensive rat model of CKD, the Lewis Polycystic Kidney (LPK) rat. METHODS Mixed-sex LPK and Lewis control rats (total n = 38) were allocated to treated (amlodipine 20 mg/kg/day p.o. from 4 to 18 weeks) and vehicle groups. Following systolic blood pressure and renal function assessment, animals were euthanized and mesenteric vasculature was collected for functional and structural assessment using pressure myography and histology. RESULTS Amlodipine treatment reduced LPK rat blood pressure (untreated vs. treated: 185 ± 5 vs. 165 ± 9 mm Hg; P = 0.019), reduced plasma creatinine (untreated vs. treated: 197 ± 17 vs. 140 ± 16 µmol/l; P = 0.002), and improved some vascular structural parameters (internal and external diameters and wall–lumen ratios); however wall thickness was still increased in LPK relative to Lewis despite treatment (Lewis vs. LPK: 31 ± 2 vs. 41 ± 2 µm, P = 0.047). Treatment improved LPK rats’ endothelium dysfunction, and nitric oxide-dependent and endothelium-derived hyperpolarization vasorelaxation components, and downregulated prostanoid contributions. LTCC blockade had no effect on biomechanical properties of compliance and intrinsic stiffness, nor artery wall composition. CONCLUSIONS Our results indicate that blockade of LTCCs with amlodipine is effective in improving, to a certain extent, detrimental structural and functional vascular features of resistance arteries in CKD.

A constitutive modeling interpretation of the relationship among carotid artery stiffness, blood pressure, and age in hypertensive subjects

2015 ◽  
Vol 308 (6) ◽  
pp. H568-H582 ◽  
Author(s):  
Bart Spronck ◽  
Maarten H. G. Heusinkveld ◽  
Wouter P. Donders ◽  
Anouk G. W. de Lepper ◽  
Jos Op't Roodt ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Constitutive Modeling ◽  
Arterial Wall ◽  
Wall Stress ◽  
Wall Structure ◽  
Age Related ◽  
Artery Stiffness ◽  
Pressure Area ◽  
And Function ◽  
The Relationship

Aging has a profound influence on arterial wall structure and function. We have previously reported the relationship among pulse wave velocity, age, and blood pressure in hypertensive subjects. In the present study, we aimed for a quantitative interpretation of the observed changes in wall behavior with age using a constitutive modeling approach. We implemented a model of arterial wall biomechanics and fitted this to the group-averaged pressure-area ( P-A) relationship of the “young” subgroup of our study population. Using this model as our take-off point, we assessed which parameters had to be changed to let the model describe the “old” subgroup’s P-A relationship. We allowed elastin stiffness and collagen recruitment parameters to vary and adjusted residual stress parameters according to published age-related changes. We required wall stress to be homogeneously distributed over the arterial wall and assumed wall stress normalization with age by keeping average “old” wall stress at the “young” level. Additionally, we required axial force to remain constant over the cardiac cycle. Our simulations showed an age-related shift in pressure-load bearing from elastin to collagen, caused by a decrease in elastin stiffness and a considerable increase in collagen recruitment. Correspondingly, simulated diameter and wall thickness increased by about 20 and 17%, respectively. The latter compared well with a measured thickness increase of 21%. We conclude that the physiologically realistic changes in constitutive properties we found under physiological constraints with respect to wall stress could well explain the influence of aging in the stiffness-pressure-age pattern observed.

The influence of osteopathic correction on the rate of various rhythms of the body

2019 ◽  
pp. 64-71 ◽  
Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Age Groups ◽  
Biomechanical Properties ◽  
Dispersion Analysis ◽  
The Body ◽  
Body Tissues ◽  
Age Related ◽  
Significant Difference ◽  
Before And After

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.

Hemodynamic Patterns of Age-Related Changes in Blood Pressure

Circulation ◽  
1997 ◽  
Vol 96 (1) ◽  
pp. 308-315 ◽  
Author(s):  
Stanley S. Franklin ◽  
William Gustin ◽  
Nathan D. Wong ◽  
Martin G. Larson ◽  
Michael A. Weber ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Age Related ◽  
Age Related Changes

The smoothness index, but not the trough-to-peak ratio predicts changes in carotid artery wall thickness during antihypertensive treatment

2001 ◽  
Vol 19 (4) ◽  
pp. 703-711 ◽  
Author(s):  
Damiano Rizzoni ◽  
Maria Lorenza Muiesan ◽  
Massimo Salvetti ◽  
Maurizio Castellano ◽  
Giorgio Bettoni ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Wall Thickness ◽  
Antihypertensive Treatment ◽  
Peak Ratio ◽  
Artery Wall ◽  
Carotid Artery Wall ◽  
Smoothness Index

Optimization of a decellularization protocol of porcine tracheas. Long-term effects of cryopreservation. A histological study

2021 ◽  
pp. 039139882110089
Author(s):  
Lara Milian ◽  
María Sancho-Tello ◽  
Joan Roig-Soriano ◽  
Giovanna Foschini ◽  
Néstor J Martínez-Hernández ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Histological Study ◽  
Biomechanical Properties ◽  
Elastic Fibers ◽  
Appreciable Effect ◽  
Long Term Effects ◽  
Minimal Impact ◽  
Biomechanical Effect ◽  
Triton X

Objective: The aim of this study was to optimize a decellularization protocol in the trachea of Sus scrofa domestica (pig) as well as to study the effects of long-term cryopreservation on the extracellular matrix of decellularized tracheas. Methods: Porcine tracheas were decellularized using Triton X-100, SDC, and SDS alone or in combination. The effect of these detergents on the extracellular matrix characteristics of decellularized porcine tracheas was evaluated at the histological, biomechanical, and biocompatibility level. Morphometric approaches were used to estimate the effect of detergents on the collagen and elastic fibers content as well as on the removal of chondrocytes from decellularized organs. Moreover, the long-term structural, ultrastructural, and biomechanical effect of cryopreservation of decellularized tracheas were also estimated. Results: Two percent SDS was the most effective detergent tested concerning cell removal and preservation of the histological and biomechanical properties of the tracheal wall. However, long-term cryopreservation had no an appreciable effect on the structure, ultrastructure, and biomechanics of decellularized tracheal rings. Conclusion: The results presented here reinforce the use of SDS as a valuable decellularizing agent for porcine tracheas. Furthermore, a cryogenic preservation protocol is described, which has minimal impact on the histological and biomechanical properties of decellularized porcine tracheas.

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