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Joshi K, Diaz A, O'Keeffe K, Schaffer JD, Chiarot PR, Huang P. Flow in temporally and spatially varying porous media: a model for transport of interstitial fluid in the brain. J Math Biol 2024; 88:69. [PMID: 38664246 DOI: 10.1007/s00285-024-02092-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 02/02/2024] [Accepted: 04/02/2024] [Indexed: 05/12/2024]
Abstract
Flow in a porous medium can be driven by the deformations of the boundaries of the porous domain. Such boundary deformations locally change the volume fraction accessible by the fluid, creating non-uniform porosity and permeability throughout the medium. In this work, we construct a deformation-driven porous medium transport model with spatially and temporally varying porosity and permeability that are dependent on the boundary deformations imposed on the medium. We use this model to study the transport of interstitial fluid along the basement membranes in the arterial walls of the brain. The basement membrane is modeled as a deforming annular porous channel with the compressible pore space filled with an incompressible, Newtonian fluid. The role of a forward propagating peristaltic heart pulse wave and a reverse smooth muscle contraction wave on the flow within the basement membranes is investigated. Our results identify combinations of wave amplitudes that can induce either forward or reverse transport along these transport pathways in the brain. The magnitude and direction of fluid transport predicted by our model can help in understanding the clearance of fluids and solutes along the Intramural Periarterial Drainage route and the pathology of cerebral amyloid angiopathy.
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Affiliation(s)
- Ketaki Joshi
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Adrian Diaz
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Katherine O'Keeffe
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - J David Schaffer
- Institute for Justice and Well-Being, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Paul R Chiarot
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Peter Huang
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA.
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2
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Jensen LJ. Functional, Structural and Proteomic Effects of Ageing in Resistance Arteries. Int J Mol Sci 2024; 25:2601. [PMID: 38473847 DOI: 10.3390/ijms25052601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/18/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
The normal ageing process affects resistance arteries, leading to various functional and structural changes. Systolic hypertension is a common occurrence in human ageing, and it is associated with large artery stiffening, heightened pulsatility, small artery remodeling, and damage to critical microvascular structures. Starting from young adulthood, a progressive elevation in the mean arterial pressure is evidenced by clinical and epidemiological data as well as findings from animal models. The myogenic response, a protective mechanism for the microcirculation, may face disruptions during ageing. The dysregulation of calcium entry channels (L-type, T-type, and TRP channels), dysfunction in intracellular calcium storage and extrusion mechanisms, altered expression of potassium channels, and a change in smooth muscle calcium sensitization may contribute to the age-related dysregulation of myogenic tone. Flow-mediated vasodilation, a hallmark of endothelial function, is compromised in ageing. This endothelial dysfunction is related to increased oxidative stress, lower nitric oxide bioavailability, and a low-grade inflammatory response, further exacerbating vascular dysfunction. Resistance artery remodeling in ageing emerges as a hypertrophic response of the vessel wall that is typically observed in conjunction with outward remodeling (in normotension), or as inward hypertrophic remodeling (in hypertension). The remodeling process involves oxidative stress, inflammation, reorganization of actin cytoskeletal components, and extracellular matrix fiber proteins. Reactive oxygen species (ROS) signaling and chronic low-grade inflammation play substantial roles in age-related vascular dysfunction. Due to its role in the regulation of vascular tone and structural proteins, the RhoA/Rho-kinase pathway is an important target in age-related vascular dysfunction and diseases. Understanding the intricate interplay of these factors is crucial for developing targeted interventions to mitigate the consequences of ageing on resistance arteries and enhance the overall vascular health.
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Affiliation(s)
- Lars Jørn Jensen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-1870 Frederiksberg C, Denmark
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3
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Behringer EJ. Impact of aging on vascular ion channels: perspectives and knowledge gaps across major organ systems. Am J Physiol Heart Circ Physiol 2023; 325:H1012-H1038. [PMID: 37624095 PMCID: PMC10908410 DOI: 10.1152/ajpheart.00288.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/21/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
Individuals aged ≥65 yr will comprise ∼20% of the global population by 2030. Cardiovascular disease remains the leading cause of death in the world with age-related endothelial "dysfunction" as a key risk factor. As an organ in and of itself, vascular endothelium courses throughout the mammalian body to coordinate blood flow to all other organs and tissues (e.g., brain, heart, lung, skeletal muscle, gut, kidney, skin) in accord with metabolic demand. In turn, emerging evidence demonstrates that vascular aging and its comorbidities (e.g., neurodegeneration, diabetes, hypertension, kidney disease, heart failure, and cancer) are "channelopathies" in large part. With an emphasis on distinct functional traits and common arrangements across major organs systems, the present literature review encompasses regulation of vascular ion channels that underlie blood flow control throughout the body. The regulation of myoendothelial coupling and local versus conducted signaling are discussed with new perspectives for aging and the development of chronic diseases. Although equipped with an awareness of knowledge gaps in the vascular aging field, a section has been included to encompass general feasibility, role of biological sex, and additional conceptual and experimental considerations (e.g., cell regression and proliferation, gene profile analyses). The ultimate goal is for the reader to see and understand major points of deterioration in vascular function while gaining the ability to think of potential mechanistic and therapeutic strategies to sustain organ perfusion and whole body health with aging.
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Affiliation(s)
- Erik J Behringer
- Basic Sciences, Loma Linda University, Loma Linda, California, United States
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Aging-Related Structural and Functional Changes in Cerebral Arteries: Caloric Restriction (CR) Intervention. JOURNAL OF VASCULAR MEDICINE & SURGERY 2021; 9:1000002. [PMID: 34981030 PMCID: PMC8720434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Cerebral arteries play a crucial role in the regulation of blood flow to the brain to satisfy the demand of oxygen and glucose for proper function of the organ. Physiological cerebral blood flow (CBF) is maintained within a normal range in response to changes in blood pressure a mechanism named Cerebral Blood Flow Auto Regulation (CBFAR). Structure and function of cerebral arteries have an important impact on CBFAR. Several studies in human and animals have showed significant morphological and functional changes in cerebral vessels of aged brain associated with a reduced CBF which is also impaired in cerebrovascular pathology linked to brain diseases. Interestingly, one new emergent aspect is the lifelong Calorie Restriction (CR) as a potential intervention to prevent age-related cerebral artery changes and preserve the health of aging brain. This review summarizes the recent literature on the effects of aging on cerebral artery structure and function and the potential of CR as opportunities for prevention and treatment.
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Aldea R, Weller RO, Wilcock DM, Carare RO, Richardson G. Cerebrovascular Smooth Muscle Cells as the Drivers of Intramural Periarterial Drainage of the Brain. Front Aging Neurosci 2019; 11:1. [PMID: 30740048 PMCID: PMC6357927 DOI: 10.3389/fnagi.2019.00001] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/07/2019] [Indexed: 12/25/2022] Open
Abstract
The human brain is the organ with the highest metabolic activity but it lacks a traditional lymphatic system responsible for clearing waste products. We have demonstrated that the basement membranes of cerebral capillaries and arteries represent the lymphatic pathways of the brain along which intramural periarterial drainage (IPAD) of soluble metabolites occurs. Failure of IPAD could explain the vascular deposition of the amyloid-beta protein as cerebral amyloid angiopathy (CAA), which is a key pathological feature of Alzheimer's disease. The underlying mechanisms of IPAD, including its motive force, have not been clarified, delaying successful therapies for CAA. Although arterial pulsations from the heart were initially considered to be the motive force for IPAD, they are not strong enough for efficient IPAD. This study aims to unravel the driving force for IPAD, by shifting the perspective of a heart-driven clearance of soluble metabolites from the brain to an intrinsic mechanism of cerebral arteries (e.g., vasomotion-driven IPAD). We test the hypothesis that the cerebrovascular smooth muscle cells, whose cycles of contraction and relaxation generate vasomotion, are the drivers of IPAD. A novel multiscale model of arteries, in which we treat the basement membrane as a fluid-filled poroelastic medium deformed by the contractile cerebrovascular smooth muscle cells, is used to test the hypothesis. The vasomotion-induced intramural flow rates suggest that vasomotion-driven IPAD is the only mechanism postulated to date capable of explaining the available experimental observations. The cerebrovascular smooth muscle cells could represent valuable drug targets for prevention and early interventions in CAA.
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Affiliation(s)
- Roxana Aldea
- Mathematical Sciences, University of Southampton, Southampton, United Kingdom
| | - Roy O Weller
- Clinical Neurosciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | - Donna M Wilcock
- Department of Physiology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States
| | - Roxana O Carare
- Clinical Neurosciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | - Giles Richardson
- Mathematical Sciences, University of Southampton, Southampton, United Kingdom
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Ivic I, Vamos Z, Cseplo P, Koller A. From Newborn to Senescence Morphological and Functional Remodeling Leads to Increased Contractile Capacity of Arteries. J Gerontol A Biol Sci Med Sci 2017; 72:481-488. [PMID: 27190209 DOI: 10.1093/gerona/glw085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/19/2016] [Indexed: 11/15/2022] Open
Abstract
Aging induces substantial morphological and functional changes in vessels. We hypothesized that due to morphological remodeling the total contractile forces of arteries increase, especially in older age as a function of age. Mean arterial blood pressure of rats and morphological and functional characteristics of isolated carotid arteries rats, from newborn to senescent, were assessed. The arterial blood pressure of rats increased significantly from 0.25 to the age of 6 months, and then it reached a level, which was maintained until age of 30 months. Wall lumen and wall thickness increased with age, mostly due to media (smooth muscle) thickening, whereas wall tension gradually reduced with age. Contractions of arteries to nonreceptor-mediated vasomotor agent (KCl, 60mM) increased in three consecutive age groups, whereas contractility first increased (until 2 months), then it did not change further with aging. Norepinephrine-induced contractions initially increased in young age and then did not change further in older age. These findings suggest that during normal aging due to remodeling of arterial wall (smooth muscle) the contractile capacity of arteries increases, which seems to be independent from systemic blood pressure. Thus, arterial remodeling can favor the development of increased circulatory resistance in older age.
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Affiliation(s)
- Ivan Ivic
- Institute for Translational Medicine, Medical School, and Szentagothai Res Center.,Department of Anatomy, Medical School, and
| | - Zoltan Vamos
- Department of Anesthesiology and Intensive Therapy, University of Pécs, Hungary
| | - Peter Cseplo
- Department of Central Anesthesiology and Intensive Therapy, Petz Aladar County Teaching Hospital, Gyor, Hungary
| | - Akos Koller
- Institute of Natural Sciences, University of Physical Education, Budapest, Hungary.,Department of Physiology, New York Medical College, Valhalla
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Lubomirov LT, Papadopoulos S, Pütz S, Welter J, Klöckener T, Weckmüller K, Ardestani MA, Filipova D, Metzler D, Metzner H, Staszewski J, Zittrich S, Gagov H, Schroeter MM, Pfitzer G. Aging-related alterations in eNOS and nNOS responsiveness and smooth muscle reactivity of murine basilar arteries are modulated by apocynin and phosphorylation of myosin phosphatase targeting subunit-1. J Cereb Blood Flow Metab 2017; 37:1014-1029. [PMID: 27193035 PMCID: PMC5363478 DOI: 10.1177/0271678x16649402] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 12/20/2022]
Abstract
Aging causes major alterations of all components of the neurovascular unit and compromises brain blood supply. Here, we tested how aging affects vascular reactivity in basilar arteries from young (<10 weeks; y-BA), old (>22 months; o-BA) and old (>22 months) heterozygous MYPT1-T-696A/+ knock-in mice. In isometrically mounted o-BA, media thickness was increased by ∼10% while the passive length tension relations were not altered. Endothelial denudation or pan-NOS inhibition (100 µmol/L L-NAME) increased the basal tone by 11% in y-BA and 23% in o-BA, while inhibition of nNOS (1 µmol/L L-NPA) induced ∼10% increase in both ages. eNOS expression was ∼2-fold higher in o-BA. In o-BA, U46619-induced force was augmented (pEC50 ∼6.9 vs. pEC50 ∼6.5) while responsiveness to DEA-NONOate, electrical field stimulation or nicotine was decreased. Basal phosphorylation of MLC20-S19 and MYPT1-T-853 was higher in o-BA and was reversed by apocynin. Furthermore, permeabilized o-BA showed enhanced Ca2+-sensitivity. Old T-696A/+ BA displayed a reduced phosphorylation of MYPT1-T696 and MLC20, a lower basal tone in response to L-NAME and a reduced eNOS expression. The results indicate that the vascular hypercontractility found in o-BA is mediated by inhibition of MLCP and is partially compensated by an upregulation of endothelial NO release.
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Affiliation(s)
| | | | - Sandra Pütz
- Institute of Vegetative Physiology, University of Cologne, Germany
| | - Johannes Welter
- Institute of Vegetative Physiology, University of Cologne, Germany
| | - Tim Klöckener
- Institute for Genetics, University of Cologne, Germany
| | | | | | - Dilyana Filipova
- Institute of Vegetative Physiology, University of Cologne, Germany
| | - Doris Metzler
- Institute of Vegetative Physiology, University of Cologne, Germany
| | - Harald Metzner
- Institute of Vegetative Physiology, University of Cologne, Germany
| | | | - Stefan Zittrich
- Institute of Vegetative Physiology, University of Cologne, Germany
| | - Hristo Gagov
- Faculty of Biology, Sofia University St. Kliment Ohridski, Sofia, Bulgaria
| | | | - Gabriele Pfitzer
- Institute of Vegetative Physiology, University of Cologne, Germany
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8
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Gittemeier EM, Ericson T, Ghosh P, Copp SW, Opoku-Acheampong AB, Behnke BJ. Effects of aging and exercise training on the dynamics of vasoconstriction in skeletal muscle resistance vessels. Eur J Appl Physiol 2017; 117:397-407. [PMID: 28154974 DOI: 10.1007/s00421-017-3541-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 01/09/2017] [Indexed: 11/24/2022]
Abstract
It is unknown whether aging or exercise training affect the dynamics of arteriolar vasoconstriction. PURPOSE We hypothesized that old age will slow, and exercise training will speed, the dynamics of skeletal muscle arteriolar vasoconstriction in resistance vessels of aged rats. METHOD Young (6 month old) and aged (24 month old) male Fischer-344 rats were assigned to sedentary (Sed: n = 6/age group) or exercise-trained (ET: n = 5 aged and 6 young; via treadmill running for 10-12 weeks) groups. After completion of training, arterioles from the red portion of the gastrocnemius muscle were removed, cannulated, and exposed to 10-4 M norepinephrine (NE) or 20 mM caffeine. Changes in luminal diameter were recorded for analysis of constrictor dynamics. RESULT Old age blunted all kinetic parameters (i.e., time delay, time constant) resulting in vasoconstriction taking ~3 times as long to reach a steady state (SS) versus younger counterparts for NE (aged-sed: 15.6 ± 6.0 versus young-sed: 4.6 ± 0.5 s; P < 0.05) with a similar time course to caffeine. Exercise training resulted in a similar time to SS between age groups for NE (aged-ET: 6.8 ± 1.6 versus young-ET: 7.0 ± 0.6 s) and caffeine (aged-ET: 7.8 ± 0.6 versus young-ET: 8.6 ± 1.0 s). CONCLUSION The results of this study demonstrate that aging blunts the rate of vasoconstriction in skeletal muscle resistance vessels to the sympathetic neurotransmitter NE due, in part, to an attenuated rate of contraction from intracellular calcium release. Further, exercise training speeds the dynamics of constriction to both NE and caffeine with old age.
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Affiliation(s)
| | - Tyler Ericson
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Payal Ghosh
- Department of Food, Nutrition and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Steven W Copp
- Department of Kinesiology, Kansas State University, Manhattan, KS, USA
| | | | - Bradley J Behnke
- Department of Kinesiology, Kansas State University, Manhattan, KS, USA. .,Department of Kinesiology, Johnson Cancer Research Center, Kansas State University, Manhattan, KS, 66506, USA.
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9
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Toklu HZ, Scarpace PJ, Sakarya Y, Kirichenko N, Matheny M, Bruce EB, Carter CS, Morgan D, Tümer N. Intracerebroventricular tempol administration in older rats reduces oxidative stress in the hypothalamus but does not change STAT3 signalling or SIRT1/AMPK pathway. Appl Physiol Nutr Metab 2016; 42:59-67. [PMID: 28006433 DOI: 10.1139/apnm-2016-0067] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hypothalamic inflammation and increased oxidative stress are believed to be mechanisms that contribute to obesity. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol), a free radical scavenger, has been shown to reduce inflammation and oxidative stress. We hypothesized that brain infusion of tempol would reduce oxidative stress, and thus would reduce food intake and body weight and improve body composition in rats with age-related obesity and known elevated oxidative stress. Furthermore, we predicted an associated increase in markers of leptin signalling, including the silent mating type information regulator 2 homolog 1 (SIRT1)/5'AMP-activated protein kinase (AMPK) pathway and the signal transducer and activator of transcription 3 (STAT3) pathway. For this purpose, osmotic minipumps were placed in the intracerebroventricular region of young (3 months) and aged (23 months) male Fischer 344 x Brown Norway rats for the continuous infusion of tempol or vehicle for 2 weeks. Tempol significantly decreased (p < 0.01) nicotinamide adenine dinucleotide phosphate oxidase activity in the hypothalamus but failed to reduce food intake or weight gain and did not alter body composition. SIRT1 activity and Acetyl p53 were decreased and phosphorylation of AMPK was increased with age, but they were unchanged with tempol. Basal phosphorylation of STAT3 was unchanged with age or tempol. These results indicate that tempol decreases oxidative stress but fails to alter feeding behaviour, body weight, or body composition. Moreover, tempol does not modulate the SIRT1/AMPK/p53 pathway and does not change leptin signalling. Thus, a reduction in hypothalamic oxidative stress is not sufficient to reverse age-related obesity.
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Affiliation(s)
- Hale Z Toklu
- a Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32608, USA.,b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Philip J Scarpace
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Yasemin Sakarya
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Nataliya Kirichenko
- a Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32608, USA.,b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Michael Matheny
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Erin B Bruce
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Christy S Carter
- c Department of Aging and Geriatric Research, University of Florida, Gainesville, FL 32610, USA
| | - Drake Morgan
- d Department of Psychiatry, University of Florida, Gainesville, FL 32610, USA
| | - Nihal Tümer
- a Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32608, USA.,b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
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Uslu B, Cakmak YO, Sehirli Ü, Keskinoz EN, Cosgun E, Arbak S, Yalin A. Early Onset of Atherosclerosis of The Carotid Bifurcation in Newborn Cadavers. J Clin Diagn Res 2016; 10:AC01-5. [PMID: 27437199 DOI: 10.7860/jcdr/2016/19827.7706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 04/18/2016] [Indexed: 11/24/2022]
Abstract
INTRODUCTION The anatomy of arterial bifurcations affects blood flow and has a significant role in the development of vascular disease. Therefore, it is important to know the structural characteristics of the Common Carotid Artery (CCA) and its branches for early onset of atherosclerosis in newborns. AIM The present study was conducted to evaluate the characteristics of CCA in newborn cadavers. MATERIALS AND METHODS Eight carotid arteries obtained from newborn cadavers were used. The outflow to inflow area ratios was calculated to evaluate vessel diameters. Additionally, scanning electron and light microscopic investigations were conducted with tissue samples. The brachial artery of each cadaver was used as controls. Correlation between area ratios and atherosclerotic endothelial damage was determined. RESULTS Light microscopic investigations demonstrated that control group sections showed no positivity for Oil red O staining, while carotid bifurcation regions depicted widespread occurrence of intimal lipid accumulations. Scanning electron microscopic examination of control group sections presented regular endothelial topography, while carotid bifurcation region topography exhibited numerous blood cells and separated endothelial cells. Fibrin accumulation on endothelial surface in low area ratios was another important finding in the examination of its endothelial surface degeneration. The above-mentioned morphological findings seemed to be quite parallel to outflow to inflow area ratio data favouring low area and degeneration. CONCLUSION The correlation between area ratios and the histological characteristic of cerebral vessels of newborn cadavers indicate that early stages of atherosclerosis began in early embryologic life.
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Affiliation(s)
- Bahar Uslu
- PhD, Department of Obstetrics and Gynaecology, Yale School of Medicine , New Haven, CT, USA
| | - Yusuf Ozgur Cakmak
- Department of Anatomy, School of Medicine, Koc University , Istanbul, Turkey
| | - Ümit Sehirli
- Department of Anatomy, School of Medicine, Marmara University , Istanbul, Turkey
| | - Elif Nedret Keskinoz
- Department of Anatomy, School of Medicine, Acibadem University , Istanbul, Turkey
| | - Erdal Cosgun
- PhD, Department of Biostatistics and Medical Informatics, School of Medicine, Acibadem University , Istanbul, Turkey
| | - Serap Arbak
- PhD, Department of Histology & Embryology, School of Medicine, Acibadem University , Istanbul, Turkey
| | - Aymelek Yalin
- PhD, Department of Anatomy, School of Medicine, Eastern Mediterranean University , Famagusta, Northern Cyprus
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Albarwani SA, Mansour F, Khan AA, Al-Lawati I, Al-Kaabi A, Al-Busaidi AM, Al-Hadhrami S, Al-Husseini I, Al-Siyabi S, Tanira MO. Aging Reduces L-Type Calcium Channel Current and the Vasodilatory Response of Small Mesenteric Arteries to Calcium Channel Blockers. Front Physiol 2016; 7:171. [PMID: 27242545 PMCID: PMC4873501 DOI: 10.3389/fphys.2016.00171] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 04/25/2016] [Indexed: 01/19/2023] Open
Abstract
Calcium channel blockers (CCBs) are widely used to treat cardiovascular disease (CVD) including hypertension. As aging is an independent risk factor for CVD, the use of CCBs increases with increasing age. Hence, this study was designed to evaluate the effect of aging on the sensitivity of small mesenteric arteries to L-type voltage-gated calcium channel (LTCC) blockers and also to investigate whether there was a concomitant change in calcium current density. Third order mesenteric arteries from male F344 rats, aged 2.5-3 months (young) and 22-26 months (old) were mounted on wire myograph to measure the tension during isometric contraction. Arteries were contracted with 100 mM KCl and were then relaxed in a cumulative concentration-response dependent manner with nifedipine (0.1 nM-1 μM), verapamil (0.1 nM-10 μM), or diltiazem (0.1 nM-10 μM). Relaxation-concentration response curves produced by cumulative concentrations of three different CCBs in arteries of old rats were shifted to the right with statistically significant IC50s. pIC50 ± s.e.m: (8.37 ± 0.06 vs. 8.04 ± 0.05, 7.40 ± 0.07 vs. 6.81 ± 0.04, and 6.58 ± 0.07 vs. 6.34 ± 0.06) in young vs. old. It was observed that the maximal contractions induced by phenylephrine and reversed by sodium nitroprusside were not different between young and old groups. However, Bay K 8644 (1 μM) increased resting tension by 23 ± 4.8% in young arteries and 4.7 ± 1.6% in old arteries. LTCC current density were also significantly lower in old arteries (-2.77 ± 0.45 pA/pF) compared to young arteries (-4.5 ± 0.40 pA/pF); with similar steady-state activation and inactivation curves. Parallel to this reduction, the expression of Cav1.2 protein was reduced by 57 ± 5% in arteries from old rats compared to those from young rats. In conclusion, our results suggest that aging reduces the response of small mesenteric arteries to the vasodilatory effect of the CCBs and this may be due to, at least in part, reduced current density of LTCC.
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Affiliation(s)
- Sulayma A Albarwani
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Fathi Mansour
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Abdul Aleem Khan
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Intisar Al-Lawati
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Abdulla Al-Kaabi
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Al-Manar Al-Busaidi
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Safa Al-Hadhrami
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Isehaq Al-Husseini
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Sultan Al-Siyabi
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
| | - Musbah O Tanira
- Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health Sciences, Sultan Qaboos University Muscat, Oman
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12
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Toklu HZ, Muller-Delp J, Sakaraya Y, Oktay S, Kirichenko N, Matheny M, Carter CS, Morgan D, Strehler KYE, Tumer N, Scarpace PJ. High dietary fructose does not exacerbate the detrimental consequences of high fat diet on basilar artery function. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 2016; 67:205-216. [PMID: 27226180 PMCID: PMC5572808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/29/2016] [Indexed: 06/05/2023]
Abstract
The objective of the study was to determine the effects of a high fat (HF) diet alone or with high fructose (HF/F) on functional and structural changes in the basilar arteries and cardiovascular health parameters in rats. Male Sprague Dawley rats were fed either a HF (30%) or HF/F (30/40%) diet for 12 weeks. The basilar artery was cannulated in a pressurized system (90 cm H2O) and vascular responses to KCl (30 - 120 mM), endothelin (10(-11) - 10(-7) M), acetylcholine (ACh) (10(-10) - 10(-4) M), diethylamine (DEA)-NONO-ate (10(-10) - 10(-4) M), and papaverine (10(-10) - 10(-4) M) were evaluated. Rats were also monitored for food intake, body weight, blood lipids, blood pressure, and heart rate. At death, asymmetrical dimethyl arginine level (ADMA) and leptin were assayed in serum. Although there was no significant difference in weight gain and food intake, HF and HF/F diets increased body fat composition and decreased the lean mass. HF/F diet accelerated the development of dyslipidemia. Although resting blood pressure remained unchanged, stress caused a significant elevation in blood pressure and a modest increase in heart rate in HF fed rats. Both HF and HF/F diet resulted in decreased response to endothelium-dependent and -independent relaxation, whereas increased basilar artery wall thickness was observed only in HF group. Serum leptin levels positively correlated with wall thickness. Moreover serum ADMA was increased and eNOS immunofluorescence was significantly decreased with both diets. These data suggest that the presence of high fructose in a HF diet does not exacerbate the detrimental consequences of a HF diet on basilar artery function.
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Affiliation(s)
- H Z Toklu
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - J Muller-Delp
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Y Sakaraya
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - S Oktay
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
- School of Dentistry, Marmara University, Istanbul, Turkey
| | - N Kirichenko
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - M Matheny
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - C S Carter
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, USA
| | - D Morgan
- Department of Psychiatry, University of Florida, Gainesville, FL, USA
| | - K Y E Strehler
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - N Tumer
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - P J Scarpace
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA.
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The functional and structural changes in the basilar artery due to overpressure blast injury. J Cereb Blood Flow Metab 2015; 35:1950-6. [PMID: 26104291 PMCID: PMC4671114 DOI: 10.1038/jcbfm.2015.151] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 04/13/2015] [Accepted: 05/07/2015] [Indexed: 12/13/2022]
Abstract
Overpressure blast-wave induced brain injury (OBI) leads to progressive pathophysiologic changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema, and cerebral ischemia. The aim of this study was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague-Dawley rats were divided into three groups: Control (Naive), single OBI (30 psi peak pressure, 1 to 2 msec duration), and repeated (days 1, 4, and 7) OBI (r-OBI). Rats were killed 24 hours after injury and the basilar artery was isolated, cannulated, and pressurized (90 cm H2O). Vascular responses to potassium chloride (KCl) (30 to 100 mmol/L), endothelin-1 (10(-12) to 10(-7) mol/L), acetylcholine (ACh) (10(-10) to 10(-4) mol/L) and diethylamine-NONO-ate (DEA-NONO-ate) (10(-10) to 10(-4) mol/L) were evaluated. The OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and r-OBI groups. However, impaired DEA-NONO-ate-induced vasodilation and increased wall thickness to lumen ratio were observed only in the r-OBI group. The endothelin-1 type A (ET(A)) receptor and endothelial nitric oxide synthase (eNOS) immunoreactivity were significantly enhanced by OBI. These findings indicate that both single and r-OBI impairs cerebral vascular endothelium-dependent dilation, potentially a consequence of endothelial dysfunction and/or vascular remodelling in basilar arteries after OBI.
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