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Piknova B, Park JW, Thomas SM, Tunau-Spencer KJ, Schechter AN. Nitrate and Nitrite Metabolism in Aging Rats: A Comparative Study. Nutrients 2023; 15:nu15112490. [PMID: 37299453 DOI: 10.3390/nu15112490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Nitric oxide (NO) (co)regulates many physiological processes in the body. Its short-lived free radicals force synthesis in situ and on-demand, without storage possibility. Local oxygen availability determines the origin of NO-either by synthesis by nitric oxide synthases (NOS) or by the reduction of nitrate to nitrite to NO by nitrate/nitrite reductases. The existence of nitrate reservoirs, mainly in skeletal muscle, assures the local and systemic availability of NO. Aging is accompanied by changes in metabolic pathways, leading to a decrease in NO availability. We explored age-related changes in various rat organs and tissues. We found differences in nitrate and nitrite contents in tissues of old and young rats at baseline levels, with nitrate levels being generally higher and nitrite levels being generally lower in old rats. However, there were no differences in the levels of nitrate-transporting proteins and nitrate reductase between old and young rats, with the exception of in the eye. Increased dietary nitrate led to significantly higher nitrate enrichment in the majority of old rat organs compared to young rats, suggesting that the nitrate reduction pathway is not affected by aging. We hypothesize that age-related NO accessibility changes originate either from the NOS pathway or from changes in NO downstream signaling (sGC/PDE5). Both possibilities need further investigation.
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Affiliation(s)
- Barbora Piknova
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Ji Won Park
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Samantha M Thomas
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Khalid J Tunau-Spencer
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Alan N Schechter
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
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Cupitra NI, Calderón JC, Narvaez-Sanchez R. Influence of Ageing on Vascular Reactivity and Receptor Expression in Rabbit Aorta: A Complement to Elastocalcinosis and Smooth Muscle Mechanisms. Clin Interv Aging 2020; 15:537-545. [PMID: 32368020 PMCID: PMC7182455 DOI: 10.2147/cia.s236173] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 02/26/2020] [Indexed: 11/23/2022] Open
Abstract
Aim To contribute to the knowledge about the mechanisms involved in aortic stiffness due to ageing. Materials and Methods Aortic rings from young (1.5±0.5 months, 0.8±0.2 kg), adult (6±0.5 months, 2.7±0.5 kg) and old (28±8 months, 3.2±0.8 kg) male New Zealand rabbits were used to evaluate: 1) intima-media thickness by optical microscopy; 2) vascular reactivity (VR) in terms of sensitivity (pD2) and efficacy (Emax) to KCl; phenylephrine (PE); U-46619, a thromboxane A2 receptor agonist, TXA2; carbachol (CCh), isoproterenol and sodium nitroprusside (SNP), using organ bath experiments; and 3) the expression of receptors α1, β2 and thromboxane-prostanoids (TP), by immunofluorescence. Results Ageing 1) did not change the thickness of tunica; 2) significantly reduced the pD2 to KCl, increased the pD2 to PE and reduced both the pD2 and Emax to TXA2, CCh and isoproterenol, and reduced the pD2 to SNP; and 3) significantly increased the expression of α1 and β2 receptors in the intima and adventitia, and the expression of TP only in the adventitia. Conclusion Our results suggest that ageing makes the aorta more reactive to α1 adrenergic contraction, and it could be a compensation for lower responsiveness to prostanoids. The aged aorta is less reactive to endothelium-dependent and non-dependent relaxation, and the vessel seems to try to compensate for that stiffness increasing β2 receptors, although probably less functional. These results complement the proposed mechanisms of elastocalcinosis and smooth muscle rigidity, expanding the vision that should guide the treatment of aortic stiffness due to aging.
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Affiliation(s)
- Nelson Ivan Cupitra
- Physiology and Biochemistry Research Group-PHYSIS, Faculty of Medicine, University of Antioquia, Medellin, Colombia
| | - Juan C Calderón
- Physiology and Biochemistry Research Group-PHYSIS, Faculty of Medicine, University of Antioquia, Medellin, Colombia
| | - Raul Narvaez-Sanchez
- Physiology and Biochemistry Research Group-PHYSIS, Faculty of Medicine, University of Antioquia, Medellin, Colombia
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Paz AA, Arenas GA, Castillo-Galán S, Peñaloza E, Cáceres-Rojas G, Suazo J, Herrera EA, Krause BJ. Premature Vascular Aging in Guinea Pigs Affected by Fetal Growth Restriction. Int J Mol Sci 2019; 20:ijms20143474. [PMID: 31311132 PMCID: PMC6678381 DOI: 10.3390/ijms20143474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/05/2019] [Accepted: 07/13/2019] [Indexed: 12/16/2022] Open
Abstract
Cardiovascular risk associated with fetal growth restriction (FGR) could result from an early impaired vascular function. However, whether this effect results in premature vascular aging has not been addressed. We studied the ex vivo reactivity of carotid and femoral arteries in fetal (near term), adults (eight months-old) and aged (16 months-old) guinea pigs in normal (control) and FGR offspring. Additionally, an epigenetic marker of vascular aging (i.e., LINE-1 DNA methylation) was evaluated in human umbilical artery endothelial cells (HUAEC) from control and FGR subjects. Control guinea pig arteries showed an increased contractile response (KCl-induced) and a progressive impairment of NO-mediated relaxing responses as animals get older. FGR was associated with an initial preserved carotid artery reactivity as well as a later significant impairment in NO-mediated responses. Femoral arteries from FGR fetuses showed an increased contractility but a decreased relaxing response compared with control fetuses, and both responses were impaired in FGR-adults. Finally, FGR-HUAEC showed decreased LINE-1 DNA methylation compared with control-HUAEC. These data suggest that the aging of vascular function occurs by changes in NO-mediated responses, with limited alterations in contractile capacity. Further, these effects are accelerated and imposed at early stages of development in subjects exposed to a suboptimal intrauterine environment.
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Affiliation(s)
- Adolfo A Paz
- Department of Neonatology, Division of Paediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago 8330024, Santiago, Chile
| | - German A Arenas
- Department of Neonatology, Division of Paediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago 8330024, Santiago, Chile
- Programa de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8330024, Santiago, Chile
| | - Sebastián Castillo-Galán
- Department of Neonatology, Division of Paediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago 8330024, Santiago, Chile
- Programa de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8330024, Santiago, Chile
| | - Estefanía Peñaloza
- Department of Neonatology, Division of Paediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago 8330024, Santiago, Chile
| | - Gabriela Cáceres-Rojas
- Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Sergio Livingstone 943, Independencia 8380492, Santiago, Chile
| | - José Suazo
- Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Sergio Livingstone 943, Independencia 8380492, Santiago, Chile
| | - Emilio A Herrera
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Av. Salvador 486, Providencia 7500922, Santiago, Chile
- International Center for Andean Studies (INCAS), Universidad de Chile, Baquedano s/n, Putre, Chile
| | - Bernardo J Krause
- Department of Neonatology, Division of Paediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago 8330024, Santiago, Chile.
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COPD and stroke: are systemic inflammation and oxidative stress the missing links? Clin Sci (Lond) 2017; 130:1039-50. [PMID: 27215677 PMCID: PMC4876483 DOI: 10.1042/cs20160043] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 03/07/2016] [Indexed: 12/12/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and loss of lung function, and is currently the third largest cause of death in the world. It is now well established that cardiovascular-related comorbidities such as stroke contribute to morbidity and mortality in COPD. The mechanisms linking COPD and stroke remain to be fully defined but are likely to be interconnected. The association between COPD and stroke may be largely dependent on shared risk factors such as aging and smoking, or the association of COPD with traditional stroke risk factors. In addition, we propose that COPD-related systemic inflammation and oxidative stress may play important roles by promoting cerebral vascular dysfunction and platelet hyperactivity. In this review, we briefly discuss the pathogenesis of COPD, acute exacerbations of COPD (AECOPD) and cardiovascular comorbidities associated with COPD, in particular stroke. We also highlight and discuss the potential mechanisms underpinning the link between COPD and stroke, with a particular focus on the roles of systemic inflammation and oxidative stress.
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Boerman EM, Segal SS. Depressed perivascular sensory innervation of mouse mesenteric arteries with advanced age. J Physiol 2015; 594:2323-38. [PMID: 26010764 DOI: 10.1113/jp270710] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 05/15/2015] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS The dilatory role for sensory innervation of mesenteric arteries (MAs) is impaired in Old (∼24 months) versus Young (∼4 months) mice. We investigated the nature of this impairment in isolated pressurized MAs. With perivascular sensory nerve stimulation, dilatation and inhibition of sympathetic vasoconstriction observed in Young MAs were lost in Old MAs along with impaired dilatation to calcitonin gene-related peptide (CGRP). Inhibiting NO and prostaglandin synthesis increased CGRP EC50 in Young and Old MAs. Endothelial denudation attenuated dilatation to CGRP in Old MAs yet enhanced dilatation to CGRP in Young MAs while abolishing all dilatations to ACh. In Old MAs, sensory nerve density was reduced and RAMP1 (CGRP receptor component) associated with nuclear regions of endothelial cells in a manner not seen in Young MAs or in smooth muscle cells of either age. With advanced age, loss of dilatory signalling mediated through perivascular sensory nerves may compromise perfusion of visceral organs. ABSTRACT Vascular dysfunction and sympathetic nerve activity increase with advancing age. In the gut, blood flow is governed by perivascular sensory and sympathetic nerves but little is known of how their functional role is affected by advanced age. We tested the hypothesis that functional sensory innervation of mesenteric arteries (MAs) is impaired for Old (24 months) versus Young (4 months) C57BL/6 male mice. In cannulated pressurized MAs preconstricted 50% with noradrenaline and treated with guanethidine (to inhibit sympathetic neurotransmission), perivascular nerve stimulation (PNS) evoked dilatation in Young but not Old MAs while dilatations to ACh were not different between age groups. In Young MAs, capsaicin (to inhibit sensory neurotransmission) blocked dilatation and increased constriction during PNS. With no difference in efficacy, the EC50 of CGRP as a vasodilator was ∼6-fold greater in Old versus Young MAs. Inhibiting nitric oxide (l-NAME) and prostaglandin (indomethacin) synthesis increased CGRP EC50 in both age groups. Endothelial denudation reduced the efficacy of dilatation to CGRP by ∼30% in Old MAs yet increased this efficacy ∼15% in Young MAs while all dilatations to ACh were abolished. Immunolabelling revealed reduced density of sensory (CGRP) but not sympathetic (tyrosine hydroxylase) innervation for Old versus Young MAs. Whereas the distribution of CGRP receptor proteins was similar in SMCs, RAMP1 associated with nuclear regions of endothelial cells of Old but not Young MAs. With advanced age, the loss of sensory nerve function and diminished effectiveness of CGRP as a vasodilator is multifaceted and may adversely affect splanchnic perfusion.
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Affiliation(s)
- Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65212, USA
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65212, USA.,Dalton Cardiovascular Research Center, Columbia, MO, 65211, USA
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Loria AS, Brinson KN, Fox BM, Sullivan JC. Sex-specific alterations in NOS regulation of vascular function in aorta and mesenteric arteries from spontaneously hypertensive rats compared to Wistar Kyoto rats. Physiol Rep 2014; 2:2/8/e12125. [PMID: 25168874 PMCID: PMC4246578 DOI: 10.14814/phy2.12125] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The present study tested the hypothesis that spontaneously hypertensive rats (SHR) have impaired nitric oxide synthase (NOS)‐mediated regulation of vascular function versus Wistar‐Kyoto rats (WKY). Aorta and small mesenteric arteries were studied from male and female SHR (M SHR and F SHR) and WKY (M WKY and F WKY). Phenylephrine (PE)‐induced vasoconstriction was greater in aorta of M SHR versus all others (P < 0.05); there were neither sex nor strain differences in PE contraction in mesenteric arteries. The NOS inhibitor l‐Nitro‐Arginine Methyl Ester (l‐NAME) increased PE‐induced vasoconstriction in all rats, although the increase was the least in male SHR (P < 0.05), revealing a blunted vasoconstrictor buffering capacity of NOS. l‐NAME increased sensitivity to PE‐induced constriction only in mesenteric arteries of SHR, although, the maximal percent increase in contraction was comparable among groups. ACh‐induced relaxation was also less in aorta from M SHR versus all others (P < 0.05). ACh relaxation was comparable among groups in mesenteric arteries, although SHR exhibited a greater NOS component to ACh‐induced relaxation than WKY. To gain mechanistic insight into sex and strain differences in vascular function, NOS activity and NOS3 protein expression were measured. Aortic NOS activity was comparable between groups and M SHR had greater NOS3 expression than M WKY. In contrast, although vascular function was largely maintained in mesenteric arteries of SHR, NOS activity was less in SHR versus WKY. In conclusion, M SHR exhibit a decrease in NOS regulation of vascular function compared to F SHR and WKY, although this is not mediated by decreases in NOS activity and/or expression. The present study tested the hypothesis that spontaneously hypertensive rats (SHR) have impaired nitric oxide synthase (NOS)‐mediated regulation of vascular function versus Wistar‐Kyoto rats (WKY). Aorta and small mesenteric arteries were studied from male and female SHR and WKY. Male SHR showed a decreased NOS regulation of vascular function compared to F SHR and WKY, although this was not mediated by decreases in NOS activity and/or expression.
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Affiliation(s)
- Analia S Loria
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, St. Lexington, Kentucky
| | - Krystal N Brinson
- Department of Physiology, Georgia Regents University, Augusta, Georgia
| | - Brandon M Fox
- Department of Physiology, Georgia Regents University, Augusta, Georgia
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Epstein SE, Lassance-Soares RM, Faber JE, Burnett MS. Effects of Aging on the Collateral Circulation, and Therapeutic Implications. Circulation 2012; 125:3211-9. [DOI: 10.1161/circulationaha.111.079038] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Stephen E. Epstein
- From the Cardiovascular Research Institute, MedStar Health Research Institute, Washington, DC (S.E.E., R.M.L.-S., M.S.B.), and Department of Physiology and McAllister Heart Institute, University of North Carolina, Chapel Hill, NC (J.E.F.)
| | - Roberta M. Lassance-Soares
- From the Cardiovascular Research Institute, MedStar Health Research Institute, Washington, DC (S.E.E., R.M.L.-S., M.S.B.), and Department of Physiology and McAllister Heart Institute, University of North Carolina, Chapel Hill, NC (J.E.F.)
| | - James E. Faber
- From the Cardiovascular Research Institute, MedStar Health Research Institute, Washington, DC (S.E.E., R.M.L.-S., M.S.B.), and Department of Physiology and McAllister Heart Institute, University of North Carolina, Chapel Hill, NC (J.E.F.)
| | - Mary Susan Burnett
- From the Cardiovascular Research Institute, MedStar Health Research Institute, Washington, DC (S.E.E., R.M.L.-S., M.S.B.), and Department of Physiology and McAllister Heart Institute, University of North Carolina, Chapel Hill, NC (J.E.F.)
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Faber JE, Zhang H, Lassance-Soares RM, Prabhakar P, Najafi AH, Burnett MS, Epstein SE. Aging causes collateral rarefaction and increased severity of ischemic injury in multiple tissues. Arterioscler Thromb Vasc Biol 2011; 31:1748-56. [PMID: 21617137 DOI: 10.1161/atvbaha.111.227314] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Aging is a major risk factor for increased ischemic tissue injury. Whether collateral rarefaction and impaired remodeling contribute to this is unknown. We quantified the number and diameter of native collaterals and their remodeling in 3-, 16-, 24-, and 31-month-old mice. METHODS AND RESULTS Aging caused an "age-dose-dependent" greater drop in perfusion immediately after femoral artery ligation, followed by a diminished recovery of flow and increase in tissue injury. These effects were associated with a decline in collateral number, diameter, and remodeling. Angiogenesis was also impaired. Mechanistically, these changes were not accompanied by reduced recruitment of T cells or macrophages to remodeling collaterals. However, endothelial nitric oxide synthase signaling was dysfunctional, as indicated by increased protein nitrosylation and less phosphorylated endothelial nitric oxide synthase and vasodilator-stimulated phosphoprotein in collateral wall cells. The cerebral circulation exhibited a similar age-dose-dependent loss of collateral number and diameter and increased tortuosity, resulting in an increase in collateral resistance and infarct volume (eg, 6- and 3-fold, respectively, in 24-month-old mice) after artery occlusion. This was not associated with rarefaction of similarly sized arterioles. Collateral remodeling was also reduced. CONCLUSIONS Our findings demonstrate that aging causes rarefaction and insufficiency of the collateral circulation in multiple tissues, resulting in more severe ischemic tissue injury.
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Affiliation(s)
- James E Faber
- Department of Physiology, McAllister Heart Institute, University of North Carolina, Chapel Hill, 27599-7545, USA.
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van Drongelen J, Ploemen IHJ, Pertijs J, Gooi JH, Sweep FCGJ, Lotgering FK, Spaanderman MEA, Smits P. Aging attenuates the vasodilator response to relaxin. Am J Physiol Heart Circ Physiol 2011; 300:H1609-15. [DOI: 10.1152/ajpheart.00360.2010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Relaxin, an insulin-like growth factor peptide, increases endothelium-dependent vasodilation and vascular compliance and decreases myogenic reactivity. These vascular effects significantly contribute to the physiological circulatory adaptations in pregnancy, particularly in the mesentery and kidney. Aging predisposes to vascular maladaptation and gestational hypertensive disease. We hypothesized that mild aging reduces the vascular responses to relaxin. In 20 young (10–12 wk) and 20 middle-aged (40–46 wk) female Wistar Hannover rats, vascular responses to chronic exposure of relaxin vs. placebo (5 days) were quantified in isolated mesenteric arteries and kidney. Vascular responses were evaluated using pressure-perfusion myograph, wire myograph, and an isolated perfused rat kidney model. Rxfp1 (relaxin family peptide) gene expression was determined by quantitative polymerase chain reaction. In young rats, relaxin stimulated nitric oxide (NO)-dependent flow-mediated vasodilation (2.67-fold, from 48 ± 9 to 18 ± 4 μl/min), reduced myogenic reactivity (from −1 ± 2 to 7 ± 3 μm/10 mmHg), and decreased mesenteric sensitivity to (28%, from 1.39 ± 0.08 to 1.78 ± 0.10 μM) but did not change compliance and renal perfusion flow (RPFF). In aged rats, relaxin did not affect any of the analyzed mesenteric or renal parameters. In aged compared with young placebo-treated rats, all mesenteric characteristics were comparable, while RPFF was lower (17%, from 6.9 ± 0.2 to 5.7 ± 0.1 ml·min−1·100 g−1) even though NO availability was comparable. Rxfp1 expression was not different among young and aged rats. Our findings suggest that moderate aging involves normal endothelial function but blunts the physiological endothelium-dependent and -independent vasodilator response to relaxin.
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Affiliation(s)
| | | | | | - Jonathan H. Gooi
- Department of Zoology, University of Melbourne, Melbourne, Australia
| | - Fred C. G. J. Sweep
- Laboratory Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; and
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Hypovolemic state: age-related influence of water restriction on cardiac nitric oxide synthase in rats. Eur J Nutr 2011; 50:657-64. [DOI: 10.1007/s00394-011-0183-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Accepted: 03/01/2011] [Indexed: 10/18/2022]
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Lesniewski LA, Connell ML, Durrant JR, Folian BJ, Anderson MC, Donato AJ, Seals DR. B6D2F1 Mice are a suitable model of oxidative stress-mediated impaired endothelium-dependent dilation with aging. J Gerontol A Biol Sci Med Sci 2009; 64:9-20. [PMID: 19211548 DOI: 10.1093/gerona/gln049] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
To determine if B6D2F1 mice represent a suitable model of oxidative stress-mediated impaired endothelium-dependent dilation (EDD) with aging, mice were studied at 6.9 +/- 0.3 and 31.9 +/- 0.6 months. EDD to acetylcholine (ACh) was 26% (p < .001) and 12% (p < .001) lower, respectively, in isolated carotid (n = 10-11) and femoral (n = 10) arteries from older mice, and reductions in arterial pressure to systemic ACh infusion were smaller in older mice (n = 6-10; p < .01). Nitrotyrosine was marked in aorta of older mice (p < .05, n = 4). Superoxide production in carotid arteries was greater (p < .05), and TEMPOL restored dilation in carotid arteries and systemically in older mice. N(G)-nitro-l-arginine methyl ester (l-NAME) reduced carotid artery dilation in young more than older mice, whereas TEMPOL restored the effects of l-NAME in older mice. Carotid artery stiffness was increased in older compared with young mice (p = .04). Our results provide the first comprehensive evidence that B6D2F1 mice are a useful model for investigating mechanisms of reduced nitric oxide-dependent, oxidative stress-associated EDD and increased arterial stiffness with aging.
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Affiliation(s)
- Lisa A Lesniewski
- Department of Integrative Physiology, University of Colorado at Boulder, 80309, USA.
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Sullivan JC, Pardieck JL, Doran D, Zhang Y, She JX, Pollock JS. Greater fractalkine expression in mesenteric arteries of female spontaneously hypertensive rats compared with males. Am J Physiol Heart Circ Physiol 2009; 296:H1080-8. [PMID: 19201996 DOI: 10.1152/ajpheart.01093.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A mircoarray analysis was performed to identify novel inflammatory genes that are differentially expressed in the mesenteric arteries of male and female spontaneously hypertensive rats (SHRs). Fractalkine was found to be the inflammatory gene with the greatest differential expression in mesenteric arteries, with the expression being greater in female SHRs compared with males. Greater inflammatory mediators in female SHRs were verified by measuring urinary monocyte chemoattractant protein-1, transforming growth factor-beta, and tumor necrosis factor-alpha (TNF-alpha) excretion, all of which were greater in female SHRs compared with males. Real-time PCR, Western blot analysis, and ELISA verified greater soluble fractalkine in mesenteric arteries of female SHRs. Consistent with increased fractalkine expression, TNF-alpha-converting enzyme and TNF-alpha levels in mesenteric arteries were also greater in female SHRs. We next tested the hypothesis that mesenteric arteries from female SHRs will have greater fractalkine-induced dysfunction. Acetylcholine, sodium nitroprusside, phenylephrine, and KCl concentration-response curves were performed in third-order mesenteric arteries from male and female SHRs pretreated with either vehicle or fractalkine (1 microg/ml). Fractalkine decreased sensitivity to 1) acetylcholine in arteries from male SHRs, 2) phenylephrine in arteries from both sexes, and 3) KCl in arteries from female SHRs. In conclusion, urinary and vascular markers of inflammation are greater in female SHRs compared with males, although blood pressure and cardiovascular risk are less in females.
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Affiliation(s)
- Jennifer C Sullivan
- Vascular Biology Center, Medical College of Biotechnology and Genome Medicine, Medical College of Georgia, Austa, George, USA.
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Arreche N, Fellet A, López M, López-Costa J, Arranz C, Balaszczuk AM. Hypovolemic state: involvement of nitric oxide in the aged related alterations of aquaporins-2 abundance in rat kidney. Vascul Pharmacol 2008; 49:19-25. [PMID: 18502184 DOI: 10.1016/j.vph.2008.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 03/18/2008] [Accepted: 04/01/2008] [Indexed: 10/22/2022]
Abstract
AIM To examine the effect of nitric oxide (NO) on the expression and/or localization of inner medulla collecting duct aquaporin-2 water channel (AQP2) in young and adult hemorrhaged anesthetized rats. METHODS Rats of 2 (young) and 12 mo (adult) old (n=15) were divided into: Sham animals with and without NG-nitro-l-arginine methyl ester (L-NAME) treatment (S L-NAME and S); hemorrhaged animals (20% blood loss) with and without L-NAME (H L-NAME and H). Mean arterial pressure (MAP) was continuously monitored and AQP2 expression and inmunolocalization were evaluated at 120 min after bleeding. RESULTS L-NAME blunted the hypotension induced by hemorrhage at 120 min in young (106+/-2 mm Hg) and adult (103+/-4 mm Hg) rats. AQP2 expression increased after bleeding in young (from 22 to 50 densitometric units) and adult rats (from 15 to 30 densitometric units). Pretreatment with L-NAME enhanced this effect, being this rise lower in adult than young animals (young: 318%, adult: 233%). Electron microscopy showed that AQP2 labeling increased after withdrawal, being the number of gold particles smaller in adult than young animals in the inner medulla. L-NAME enhanced this effect. CONCLUSION NOS activity decreases AQP2 expression/traffick in the inner collecting duct principal cells in response to hemorrhage and this effect is lower with aging.
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Affiliation(s)
- Noelia Arreche
- Department of Physiology, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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Sullivan JC, Goodchild TT, Cai Z, Pollock DM, Pollock JS. Endothelin(A) (ET(A)) and ET(B) receptor-mediated regulation of nitric oxide synthase 1 (NOS1) and NOS3 isoforms in the renal inner medulla. Acta Physiol (Oxf) 2007; 191:329-36. [PMID: 17892518 DOI: 10.1111/j.1748-1716.2007.01754.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM Our laboratory and others have shown that endothelin (ET)-1 directly stimulates nitric oxide (NO) production in inner medullary collecting duct (IMCD) cells. The goal of this study was to determine which NO synthase (NOS) isoforms in IMCD are sensitive to ET-1, and the role of ET(A) and ET(B) receptor activation in vivo and in vitro. METHODS NOS enzymatic activity and NOS isoform protein expression were examined in cultured IMCD-3 cells and isolated renal inner medulla. ET(B) receptor-deficient homozygous rats (sl/sl) have elevated levels of circulating ET-1 and lack a functional ET(B) signalling pathway in kidneys, and furthermore provides a unique model to study ET(A) receptor signalling in the renal inner medulla in vivo. RESULTS Incubation of IMCD-3 cells with exogenous ET-1 (50 nm) resulted in ET(A)-dependent increased NOS1 protein expression in IMCD-3 cells with no effect on NOS2 or NOS3 expression. ET(B) receptor antagonism has no effect on NOS expression in IMCD-3 cells. Consistent with in vitro results, cytosolic NOS1 protein expression was significantly greater in the renal inner medulla of sl/sl rats compared with heterozygous (sl/+) controls, with no alteration in NOS3 expression. In contrast to protein expression data, NOS1- and NOS3-specific enzymatic activities decreased in the cytosolic fraction from the renal inner medulla of sl/sl compared with sl/+. CONCLUSION These results provide evidence that both ET(A) and ET(B) receptors regulate NOS isoform activity in the renal inner medulla and specifically support the hypothesis that ET(A) receptor activation increases NOS1 expression.
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Affiliation(s)
- J C Sullivan
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA
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15
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Sheridan KM, Ferguson MJ, Distasi MR, Witzmann FA, Dalsing MC, Miller SJ, Unthank JL. Impact of genetic background and aging on mesenteric collateral growth capacity in Fischer 344, Brown Norway, and Fischer 344 x Brown Norway hybrid rats. Am J Physiol Heart Circ Physiol 2007; 293:H3498-505. [PMID: 17906115 PMCID: PMC2859438 DOI: 10.1152/ajpheart.00040.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Available studies indicate that both genetic background and aging influence collateral growth capacity, but it is not known how their combination affects collateral growth. We evaluated collateral growth induced by ileal artery ligation in Fischer 344 (F344), Brown Norway (BN), and the first generation hybrid of F344 x BN (F1) rats available for aging research from the National Institute on Aging. Collateral growth was determined by paired diameter measurements in anesthetized rats immediately and 7 days postligation. In 3-mo-old rats, significant collateral growth occurred only in BN (35% +/- 11%, P < 0.001). The endothelial cell number in arterial cross sections was also determined, since this precedes shear-mediated luminal expansion. When compared with the same animal controls, the intimal cell number was increased only in BN rats (92% +/- 21%, P < 0.001). The increase in intimal cell number and the degree of collateral luminal expansion in BN rats was not affected by age from 3 to 24 mo. Immunohistochemical studies demonstrated that intimal cell proliferation was much greater in the collaterals of BN than of F1 rats. The remarkable difference between these three strains of rats used in aging research and the lack of an age-related impairment in the BN rats are novel observations. These rat strains mimic clinical observations of interindividual variation in collateral growth capacity and the impact of age on arteriogenesis and should be useful models to investigate the molecular mechanisms responsible for such differences.
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Affiliation(s)
- Kevin M Sheridan
- Department of Surgery, Indiana University School of Medicine, University Medical Center, 1001 W. 10th Street, Indianapolis, IN 46202-2879, USA
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16
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Kang KT, Sullivan JC, Sasser JM, Imig JD, Pollock JS. Novel nitric oxide synthase--dependent mechanism of vasorelaxation in small arteries from hypertensive rats. Hypertension 2007; 49:893-901. [PMID: 17309950 DOI: 10.1161/01.hyp.0000259669.40991.1e] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
To determine the mechanism(s) involved in vasorelaxation of small arteries from hypertensive rats, normotensive (NORM), angiotensin II-infused (ANG), high-salt (HS), ANG high-salt (ANG/HS), placebo, and deoxycorticosterone acetate-salt rats were studied. Third-order mesenteric arteries from ANG or ANG/HS displayed decreased sensitivity to acetylcholine (ACh)-induced vasorelaxation compared with NORM or HS, respectively. Maximal relaxations were comparable between groups. Blockade of Ca(2+)-activated K(+) channels had no effect on ANG versus blunting relaxation in NORM (log EC(50): -6.8+/-0.1 versus -7.2+/-0.1 mol/L). NO synthase (NOS) inhibition abolished ACh-mediated relaxation in small arteries from ANG, ANG/HS, and deoxycorticosterone acetate-salt versus blunting relaxation in NORM, HS, and placebo (% maximal relaxation: ANG: 2.7+/-1.8; ANG/HS: 7.2+/-3.2; NORM: 91+/-3.1; HS: 82.1+/-13.3; deoxycorticosterone acetate-salt: 35.2+/-17.7; placebo: 79.3+/-10.3), indicating that NOS is the primary vasorelaxation pathway in these arteries from hypertensive rats. We hypothesized that NO/cGMP signaling and NOS-dependent H(2)O(2) maintains vasorelaxation in small arteries from ANG. ACh increased NOS-dependent cGMP production, indicating that NO/cGMP signaling is present in small arteries from ANG (55.7+/-6.9 versus 30.5+/-5.1 pmol/mg), and ACh stimulated NOS-dependent H(2)O(2) production (ACh: 2.8+/-0.2 micromol/mg; N(omega)-nitro-l-arginine methyl ester hydrochloride+ACh: 1.8+/-0.1 micromol/mg) in small arteries from ANG. H(2)O(2) induced vasorelaxation and catalase blunted ACh-mediated vasorelaxation. In conclusion, Ca(2+)-activated K(+) channel-mediated relaxation is dysfunctional in small mesenteric arteries from hypertensive rats, and the NOS pathway compensates to maintain vasorelaxation in these arteries through NOS-mediated cGMP and H(2)O(2) production.
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Affiliation(s)
- Kyu-Tae Kang
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA
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17
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Behnke BJ, Prisby RD, Lesniewski LA, Donato AJ, Olin HM, Delp MD. Influence of ageing and physical activity on vascular morphology in rat skeletal muscle. J Physiol 2006; 575:617-26. [PMID: 16644803 PMCID: PMC1819439 DOI: 10.1113/jphysiol.2006.108431] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Key structural and functional properties of the skeletal muscle vasculature that underlie diminished vascular conductance with ageing remain obscure. The purpose of this investigation was to test the hypotheses that (1) reduced levels of spontaneous physical activity in old rats are associated with skeletal muscle vascular remodelling (e.g. arterial rarefaction), and (2) consequent to a vascular remodelling, calculated shear stress is maintained in feed arteries of aged muscle at levels commensurate with that in young. Activity during daily light and dark cycles (12-12 h) was measured at 30-s intervals for 2 weeks in young (6 months; n = 9) and old (24 months; n = 9) Fisher 344 rats via telemetry. Subsequently, the gastrocnemius complex and soleus muscles were excised and all feed arteries were counted, isolated, cannulated and maximally dilated for measurement of luminal diameter. Resting blood flow was also measured to estimate vessel wall shear-stress in the feed arteries perforating the soleus and gastrocnemius muscles. Overall, young rats were approximately 1.6 times more active during dark periods and approximately 4 times more active during light periods than old rats. In addition, young rats had approximately one additional feed artery perforating both the soleus (young, 3.3 +/- 0.2; old, 2.6 +/- 0.2 vessels; P < 0.05) and gastrocnemius (young, 8.8 +/- 0.1; old, 7.5 +/- 0.2 vessels, P < 0.05) muscles compared with old rats. However, average vessel wall shear stress at rest was similar between young and old rats (soleus: Y, 65 +/- 5; O, 64 +/- 5 dynes cm(-2); gastrocnemius: Y, 329 +/- 22; O, 327 +/- 27 dynes cm(-2)) resulting from a larger vessel diameter in arteries from old rats. In conclusion, lower activity levels of old rats likely contribute to resistance artery rarefaction and, consequently, this provides a plausible mechanism for the altered blood flow patterns observed during exercise in aged skeletal muscle.
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Affiliation(s)
- Bradley J Behnke
- Division of Exercise Physiology, Department of Physiology and Pharmacology, and the Center for Interdisciplinary Research in Cardiovascular Sciences, West Virginia University School of Medicine, Morgantown, WV 26506, USA
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Arenas IA, Xu Y, Davidge ST. Age-associated impairment in vasorelaxation to fluid shear stress in the female vasculature is improved by TNF-α antagonism. Am J Physiol Heart Circ Physiol 2006; 290:H1259-63. [PMID: 16284227 DOI: 10.1152/ajpheart.00990.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aging is associated with alterations in vascular homeostasis, including a reduction in flow-mediated vasodilation, which in women is related to the onset of menopause. We previously found that in female animals, aging is associated with an increase in TNF-α. Thus we investigated the role of in vivo TNF-α inhibition on vascular responses to shear stress in aging female rats. Mesenteric arteries (∼150 μm) were isolated from young (3 mo) and ovariectomized Sprague-Dawley female rats approaching reproductive senescence (12 mo) treated with either placebo or a TNF-α inhibitor (etanercept; 0.3 mg/kg) and were mounted on a pressure myograph system. Vessels were equilibrated at an intraluminal pressure of 60 mmHg and then preconstricted with phenylephrine at ∼70% of their initial diameter. Perfusate flow was increased in steps from 0 to 150 μl/min. Compared with young vessels, aged vessels have a decrease in flow-mediated dilation [maximal dilation (means ± SE): 52 ± 4 vs. 24 ± 15%; P < 0.05], which was improved by TNF-α inhibition. Moreover, in aged vessels maximal dilation to flow was achieved at higher levels of shear stress compared with young vessels. In all groups, flow-mediated dilation was abolished by either endothelial removal or nitric oxide synthase inhibition with NG-nitro-l-arginine methyl ester. However, the modulation by NG-nitro-l-arginine methyl ester was reduced in vessels from aged animals compared with young animals but was improved in the etanercept-treated aged animals. In vivo chronic TNF-α inhibition improves flow-mediated arterial dilation in resistance arteries of aged female animals.
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Affiliation(s)
- Ivan A Arenas
- Perinatal Research Centre, Department of Obstetrics and Gynecology, 220 HMRC, University of Alberta, Edmonton, Alberta, Canada T6G 2S2
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Langley-Evans SC, Sculley DV. Programming of hepatic antioxidant capacity and oxidative injury in the ageing rat. Mech Ageing Dev 2005; 126:804-12. [PMID: 15888335 DOI: 10.1016/j.mad.2005.03.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Revised: 12/16/2004] [Accepted: 03/02/2005] [Indexed: 12/12/2022]
Abstract
Exposure to undernutrition in fetal life increases the susceptibility of humans and animals to major disease states in adult life. Studies of rodents exposed to protein restriction during fetal life indicate that lifespan is reduced, a finding that is the opposite of the well-documented improvement in longevity noted with post-weaning caloric restriction. The maternal low-protein (MLP) model of rat pregnancy therefore provides a suitable vehicle to consider how nutrition in fetal life may programme mechanisms of ageing. Pregnant rats were fed control (n = 7) or MLP diet (n = 7) throughout pregnancy. At birth, increased oxidation of hepatic proteins was noted, and this appeared related to activity of glutathione reductase. Older offspring were studied at 4, 16, 30 and 44 weeks of age and analyses revealed that MLP exposure in utero produced sex-specific differences in oxidant:antioxidant balance. In male offspring, MLP increased protein carbonyl concentrations in the liver (P = 0.013) and increased glutathione peroxidase activity (P = 0.018). These programmed changes were absent in the female offspring. The data support the hypothesis that reduced lifespan in rats subject to prenatal protein restriction is a consequence of enhanced oxidative processes promoting apoptosis and loss of tissue function. Mechanisms of ageing appear to be subject to nutritional programming during early development.
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Affiliation(s)
- Simon C Langley-Evans
- Centre for Reproduction and Early Life, School of Biosciences, University of Nottingham, Sutton Bonington, Loughborough, UK.
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20
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Barton M. Ageing as a determinant of renal and vascular disease: role of endothelial factors. Nephrol Dial Transplant 2005; 20:485-90. [PMID: 15701673 DOI: 10.1093/ndt/gfh689] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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