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Savić B, Brkljačić J, Glumac S, Šarenac O, Murphy D, Blagojević D, Japundžić‐Žigon N, Dušić ZO. Effects of salt and stress on blood pressure parameters and antioxidant enzyme function in the heart and aorta of borderline hypertensive rats. Exp Physiol 2023; 108:946-960. [PMID: 37128890 PMCID: PMC10988497 DOI: 10.1113/ep090714] [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: 07/21/2022] [Accepted: 03/31/2023] [Indexed: 05/03/2023]
Abstract
NEW FINDINGS What is the central question of this study? Although the involvement of reactive oxidative species in triggering hypertension has been documented, there are no data about the role of antioxidant enzymes in the heart and aorta of borderline hypertensive rats kept in baseline conditions or exposed to high salt with or without repeated stress. What is the main finding and its importance? In borderline hypertensive rats, high salt intake and stress contribute significantly to increase blood pressure and antioxidative defence in the aorta but decrease it in the heart. Elucidating the early changes that accompany elevated blood pressure could provide new therapeutical venues for prevention and treatment of the condition. ABSTRACT Hypertension and its complications are a leading cause of death in the human population. Several factors can contribute to development of hypertension, such as genetic predisposition, high salt intake and environmental stressors, underlying oxidative stress as one of its key trademarks. We studied the effects of increased salt intake and chronic stress on blood pressure parameters and the activity and protein levels of antioxidant enzymes in the heart and aorta of borderline hypertensive rats (BHRs) with genetic susceptibility to hypertension. All animals were randomized into four groups: (1) Wistar rats kept in baseline conditions; (2) BHRs kept in baseline conditions; (3) BHRs drinking 0.9% saline solution; and (4) BHRs drinking 0.9% saline solution and exposed to repeated heterotypic stress. The BHRs exhibited significantly higher blood pressure, mitochondrial superoxide dismutase (SOD2) and catalase (CAT) protein levels and lower glutathione peroxidase (GPx) and glutathione reductase (GR) activities in the aorta, followed by lower CAT and GPx protein levels and higher CAT and GR activities in the heart, compared with normotensive Wistar rats. In the BHR aorta, high salt intake elevated CAT and GPx activities, and when combined with stress it increased GPx and GR activities. In BHR hearts, high salt intake provoked lower CAT activity. Adding repeated stress to salt treatment further decreased CAT activity, in addition to Cu2+ -Zn2+ superoxide dismutase (SOD1) and GR activities. The protein level of CAT was lower, whereas SOD2 and GPx increased. Overall, our results suggest that BHR hearts are better adapted to oxidative pressure, compared with the aorta, when exposed to salt and stress.
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Affiliation(s)
- Bojana Savić
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of MedicineUniversity of BelgradeBelgradeSerbia
| | - Jelena Brkljačić
- Department of Biochemistry, Institute for Biological Research ‘Siniša Stanković’, National Institute of Republic of SerbiaUniversity of BelgradeBelgradeSerbia
| | - Sofija Glumac
- Institute of Pathology, School of MedicineUniversity of BelgradeBelgradeSerbia
| | - Olivera Šarenac
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of MedicineUniversity of BelgradeBelgradeSerbia
| | - David Murphy
- Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin BuildingUniversity of BristolBristolUK
| | - Duško Blagojević
- Department of Physiology, Institute for Biological Research ‘Siniša Stanković’, National Institute of Republic of SerbiaUniversity of BelgradeBelgradeSerbia
| | - Nina Japundžić‐Žigon
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of MedicineUniversity of BelgradeBelgradeSerbia
| | - Zorana Oreščanin Dušić
- Department of Physiology, Institute for Biological Research ‘Siniša Stanković’, National Institute of Republic of SerbiaUniversity of BelgradeBelgradeSerbia
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Age- and Hypertension-Related Changes in NOS/NO/sGC-Derived Vasoactive Control of Rat Thoracic Aortae. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7742509. [PMID: 35308173 PMCID: PMC8926472 DOI: 10.1155/2022/7742509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/21/2021] [Accepted: 02/15/2022] [Indexed: 11/23/2022]
Abstract
This study was aimed at examining the role of the NOS/NO/sGC signaling pathway in the vasoactive control of the thoracic aorta (TA) from the early to late ontogenetic stages (7 weeks, 20 weeks, and 52 weeks old) of normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs). Systolic blood pressure (SBP) and heart rate (HR) were significantly increased in SHRs compared to age-matched WKYs, which was associated with left heart ventricle hypertrophy in all age groups of rats. The plasma urea level was increased in 20-week-old and 52-week-old SHRs compared with WKYs without increasing creatinine and uric acid. The total cholesterol levels were lower in 20-week-old and 52-week-old SHRs than in WKYs, but triglycerides were higher in 7-week-old SHRs. The fructosamine level was increased in 52-week-old SHRs compared with age-matched WKYs and unchanged in other age groups. Superoxide production was increased only in 7-week-old SHRs compared to age-matched WKYs. The endothelium-dependent relaxation (EDR) of the TA deteriorated in both rat strains during aging; however, endothelial dysfunction already occurred in 20-week-old SHRs and was even more enhanced in 52-week-old rats. Our results also demonstrated increased activity of NOS in 52-week-old WKYs. Moreover, 7-week-old and 52-week-old WKY rats displayed an enhanced residual EDR after L-NMMA (NOS inhibitor) incubation compared with 20-week-old rats. Our results showed that in 7-week-old SHRs, the residual EDR after L-NMMA incubation was increased compared to that in other age groups. The activity of NOS in the TA was comparable in 7-week-old and 20-week-old SHRs, but it was reduced in 52-week-old SHRs compared to younger SHRs and 52-week-old WKYs. Thus, it seems that, in contrast to SHRs, the NOS/NO system in WKYs is probably able to respond to age-related pathologies to maintain endothelial functions and thus optimal BP levels even in later periods of life.
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Líšková S, Bališ P, Mičurová A, Kluknavský M, Okuliarová M, Puzserová A, Škrátek M, Sekaj I, Maňka J, Valovič P, Bernátová I. Effect of iron oxide nanoparticles on vascular function and nitric oxide production in acute stress-exposed rats. Physiol Res 2020; 69:1067-1083. [PMID: 33129250 DOI: 10.33549/physiolres.934567] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We investigated whether polyethylene glycol-coated Fe3O4 nanoparticles (IONs), acute stress and their combination modifies vascular functions, nitric oxide synthase (NOS) activity, mean arterial pressure (MAP) as well as hepcidin and ferritin H gene expressions in Wistar-Kyoto rats. Rats were divided into control, ION-treated rats (1 mg Fe/kg i.v.), repeated acute air-jet stress-exposed rats and IONs-and-stress co-exposed rats. Maximal acetylcholine (ACh)-induced and sodium nitroprusside (SNP)-induced relaxations in the femoral arteries did not differ among the groups. IONs alone significantly elevated the N?-nitro-L-arginine methyl ester (L-NAME)-sensitive component of ACh-induced relaxation and reduced the sensitivity of vascular smooth muscle cells to SNP. IONs alone also elevated NOS activity in the brainstem and hypothalamus, reduced NOS activity in the kidneys and had no effect in the liver. Acute stress alone failed to affect vascular function and NOS activities in all the tissues investigated but it elevated ferritin H expression in the liver. In the ION-and-stress group, NOS activity was elevated in the kidneys and liver, but reduced in the brainstem and hypothalamus vs. IONs alone. IONs also accentuated air-jet stress-induced MAP responses vs. stress alone. Interestingly, stress reduced ION-originated iron content in blood and liver while it was elevated in the kidneys. In conclusion, the results showed that 1) acute administration of IONs altered vascular function, increased L-NAME-sensitive component of ACh-induced relaxation and had tissue-dependent effects on NOS activity, 2) ION effects were considerably reduced by co-exposure to repeated acute stress, likely related to decrease of ION-originated iron in blood due to elevated decomposition and/or excretion.
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Affiliation(s)
- S Líšková
- Institute of Pharmacology and Clinical Pharmacology, Faculty of Medicine, Comenius University, Bratislava, Slovakia, , and Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia,
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Matsumoto T, Kojima M, Takayanagi K, Taguchi K, Kobayashi T. Trimethylamine-N-oxide Specifically Impairs Endothelium-Derived Hyperpolarizing Factor-Type Relaxation in Rat Femoral Artery. Biol Pharm Bull 2020; 43:569-573. [PMID: 32115516 DOI: 10.1248/bpb.b19-00957] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although substantial evidence suggests that an increase in the level of trimethylamine-N-oxide (TMAO) is associated with the risk of cardiovascular diseases, including atherosclerosis, chronic kidney diseases, and hypertension, the direct effect of TMAO on vascular endothelial function remains unclear. Therefore, we investigated the acute effects of TMAO on endothelium-dependent relaxation induced by acetylcholine (ACh) in the superior mesenteric arteries and femoral arteries of rat. In endothelium-intact preparations, it was observed that TMAO (300 µmol/L for 60 min) did not affect ACh-induced relaxation in either of the two arteries. In endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation under nitric oxide synthase (NOS) and cyclooxygenase (COX) inhibitions by Nω-nitro-L-arginine (L-NNA) and indomethacin, respectively, TMAO specifically impairs the relaxation in femoral arteries but not in the superior mesenteric arteries. Under the inhibitory actions of NOS and as well as blockade of intermediate-conductance calcium-activated potassium channel (IKCa) (by TRAM-34) and small-conductance calcium-activated potassium channel (SKCa) (by apamin), which are putative sources of EDHF, ACh-induced relaxation was low, and there were no differences between the control and TMAO-treated groups with respect to both arteries. In femoral arteries, TMAO slightly reduces ACh-induced relaxation in the presence of indomethacin (preserved NO and EDHF signals) but does not affect ACh-induced NO-mediated relaxation under the combined presence of indomethacin, TRAM-34, and apamin. These results suggest that acute treatment with TMAO specifically impairs EDHF-mediated relaxation in the femoral arteries but not in the superior mesenteric arteries. These novel observations show that TMAO is a causative factor in the development of peripheral arterial disease.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Mihoka Kojima
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Keisuke Takayanagi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
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Kluknavsky M, Balis P, Skratek M, Manka J, Bernatova I. (-)-Epicatechin Reduces the Blood Pressure of Young Borderline Hypertensive Rats During the Post-Treatment Period. Antioxidants (Basel) 2020; 9:antiox9020096. [PMID: 31979210 PMCID: PMC7071046 DOI: 10.3390/antiox9020096] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/08/2020] [Accepted: 01/19/2020] [Indexed: 12/28/2022] Open
Abstract
This study investigated the effects of (–)-epicatechin (Epi) in young male borderline hypertensive rats (BHR) during two weeks of treatment (Epi group, 100 mg/kg/day p.o.) and two weeks post treatment (PE group). Epi reduced blood pressure (BP), which persisted for two weeks post treatment. This was associated with delayed reduction of anxiety-like behaviour. Epi significantly increased nitric oxide synthase (NOS) activities in the aorta and left heart ventricle (LHV) vs. the age-matched controls without affecting the brainstem and frontal neocortex. Furthermore, Epi significantly reduced the superoxide production in the aorta and relative content of iron-containing compounds in blood. Two weeks post treatment, the NOS activities and superoxide productions in the heart and aorta did not differ from the age-matched controls. The gene expressions of the NOSs (nNOS, iNOS, eNOS), nuclear factor erythroid 2-related factor 2 (Nrf2), and peroxisome proliferator-activated receptor-γ (PPAR-γ) remained unaltered in the aorta and LHV of the Epi and PE groups. In conclusion, while Epi-induced a decrease of the rats’ BP persisted for two weeks post treatment, continuous Epi treatments seem to be necessary for maintaining elevated NO production as well as redox balance in the heart and aorta without changes in the NOSs, Nrf2, and PPAR-γ gene expressions.
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Affiliation(s)
- Michal Kluknavsky
- Slovak Academy of Sciences, Centre of Experimental Medicine, Institute of Normal and Pathological Physiology, 813 71 Bratislava, Slovakia; (M.K.); (P.B.)
| | - Peter Balis
- Slovak Academy of Sciences, Centre of Experimental Medicine, Institute of Normal and Pathological Physiology, 813 71 Bratislava, Slovakia; (M.K.); (P.B.)
| | - Martin Skratek
- Slovak Academy of Sciences, Institute of Measurement Science, 841 04 Bratislava, Slovakia; (M.S.); (J.M.)
| | - Jan Manka
- Slovak Academy of Sciences, Institute of Measurement Science, 841 04 Bratislava, Slovakia; (M.S.); (J.M.)
| | - Iveta Bernatova
- Slovak Academy of Sciences, Centre of Experimental Medicine, Institute of Normal and Pathological Physiology, 813 71 Bratislava, Slovakia; (M.K.); (P.B.)
- Correspondence:
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Bernatova I, Puzserova A, Balis P, Sestakova N, Horvathova M, Kralovicova Z, Zitnanova I. Chronic Stress Produces Persistent Increases in Plasma Corticosterone, Reductions in Brain and Cardiac Nitric Oxide Production, and Delayed Alterations in Endothelial Function in Young Prehypertensive Rats. Front Physiol 2018; 9:1179. [PMID: 30210360 PMCID: PMC6123386 DOI: 10.3389/fphys.2018.01179] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 08/06/2018] [Indexed: 12/25/2022] Open
Abstract
This study was designed to investigate whether oxidative stress, nitric oxide (NO) deficiency and/or endothelial dysfunction (ED) are present in young borderline hypertensive rats (BHR) and whether these pathologies can be causally involved in the initiation of blood pressure (BP) increases. Additionally, we tested the hypothesis that crowding stress, experienced during the peripubertal period, may produce persistent or delayed disorders in corticosterone release, NO synthesis, oxidative status and/or endothelial function that could accelerate BP increases. To test these hypotheses, 5-week-old male BHR and normotensive Wistar-Kyoto rats (WKY) were either kept in control conditions (for 2 and 4 weeks, respectively) or exposed to social stress produced by crowding for 2 weeks (stress). After cessation of crowding, a group of rats of each phenotype was kept in control conditions for the next 2 weeks (post-stress). Systolic BP of 5-week-old BHR was significantly increased vs. age-matched WKY (127 ± 3 vs. 104 ± 3 mmHg, p < 0.01) and remained significantly higher throughout the course of the experiment. Despite elevated BP, no signs of oxidative damage to plasma lipids, NO deficiency or ED were observed in control BHR vs. age-matched WKY. Crowding stress elevated plasma corticosterone and accelerated BP increases only in BHR; these effects persisted 2 weeks post-stress. Crowding failed to induce oxidative damage to plasma lipids in either phenotype, but it produced persistent decreases in NO production in the hypothalamus and brainstem of both strains of rats, as well as in the hearts of BHR. In contrast, crowding failed to reduce NO production in the aortae or acetylcholine-induced relaxations of the femoral arteries in both strains investigated. However, significantly reduced aortic NO production was observed in BHR 2 weeks post-stress vs. age-matched controls, which was in agreement with reduced NO-dependent components of vasorelaxation. In conclusion, this study’s data showed that oxidative stress, NO deficiency and ED are not causally involved in initiation of blood pressure increase in BHR. However, exposure to stressful environments produced persistent increases in plasma corticosterone and reductions of brain and cardiac NO production followed by a delayed decrease in the NO-dependent component of endothelium-dependent relaxation—changes that collectively accelerated BP increases only in BHR.
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Affiliation(s)
- Iveta Bernatova
- Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Angelika Puzserova
- Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Peter Balis
- Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Natalia Sestakova
- Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Martina Horvathova
- Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Zuzana Kralovicova
- Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Ingrid Zitnanova
- Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University, Bratislava, Slovakia
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Park JH. Vascular Contributions to Late Life Depression. Curr Behav Neurosci Rep 2017. [DOI: 10.1007/s40473-017-0128-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Matsumoto T, Watanabe S, Iguchi M, Ando M, Oda M, Nagata M, Yamada K, Taguchi K, Kobayashi T. Mechanisms Underlying Enhanced Noradrenaline-Induced Femoral Arterial Contractions of Spontaneously Hypertensive Rats: Involvement of Endothelium-Derived Factors and Cyclooxygenase-Derived Prostanoids. Biol Pharm Bull 2016; 39:384-93. [DOI: 10.1248/bpb.b15-00821] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Shun Watanabe
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Maika Iguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Makoto Ando
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Mirai Oda
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Mako Nagata
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Kosuke Yamada
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
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Pohanka M, Ruttkay-Nedecký B, Fusek J, Adam V, Kizek R. Melatonin Regulates Oxidative Stress Initiated by Freund’s Complete Adjuvant. ACTA MEDICA (HRADEC KRÁLOVÉ) 2015; 58:21-4. [DOI: 10.14712/18059694.2015.87] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Melatonin is a hormone with strong antioxidant properties. In this experiment, Freund’s complete adjuvant was used as a stressogenic substance given to laboratory outbred mice, whereas melatonin was investigated as a protectant against the stressogenic effect. Levels of low molecular weight antioxidants, thiobarbituric acid reactive substances, and tumor necrosis factor α and activity of glutathione reductase were determined in blood from the animals. Surprisingly, melatonin was not involved in direct regulation of antioxidants, thiobarbituric acid reactive substances and tumor necrosis factor α. On the other hand, melatonin regulated glutathione reductase activity. We can conclude on regulation of metabolism caused by melatonin in the model. The effect was more important than the expected regulation of immunity and basal oxidative homeostasis.
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Endothelial dysfunction in experimental models of arterial hypertension: cause or consequence? BIOMED RESEARCH INTERNATIONAL 2014. [PMID: 24738065 DOI: 10.1155/2014/598271.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hypertension is a risk factor for other cardiovascular diseases and endothelial dysfunction was found in humans as well as in various commonly employed animal experimental models of arterial hypertension. Data from the literature indicate that, in general, endothelial dysfunction would not be the cause of experimental hypertension and may rather be secondary, that is, resulting from high blood pressure (BP). The initial mechanism of endothelial dysfunction itself may be associated with a lack of endothelium-derived relaxing factors (mainly nitric oxide) and/or accentuation of various endothelium-derived constricting factors. The involvement and role of endothelium-derived factors in the development of endothelial dysfunction in individual experimental models of hypertension may vary, depending on the triggering stimulus, strain, age, and vascular bed investigated. This brief review was focused on the participation of endothelial dysfunction, individual endothelium-derived factors, and their mechanisms of action in the development of high BP in the most frequently used rodent experimental models of arterial hypertension, including nitric oxide deficient models, spontaneous (pre)hypertension, stress-induced hypertension, and selected pharmacological and diet-induced models.
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Age-related alterations in endothelial function of femoral artery in young SHR and WKY rats. BIOMED RESEARCH INTERNATIONAL 2014; 2014:658479. [PMID: 24772431 PMCID: PMC3977421 DOI: 10.1155/2014/658479] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 02/10/2014] [Indexed: 02/07/2023]
Abstract
The present study was designed to evaluate the effects of vascular aging in juvenescence on endothelial function in femoral arteries and to assess differences between normotensive and hypertensive rats. The aim of the study was to determine if age affected nitric oxide- (NO-) mediated relaxations in normotensive and hypertensive rats. Juvenile (7-week-old) and young adult (22-week-old) male Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) were used in this study. Femoral artery (FA) reactivity was determined by wire myograph and NO synthase activity by conversion of [3H]-L-arginine. During juvenescence systolic blood pressure (tail-cuff) increased significantly only in SHR, while NO synthesis decreased significantly in both strains. Endothelium-dependent relaxations to acetylcholine were reduced in the FA of SHR compared to age-matched WKY at both ages, yet these parameters were unchanged in adult rats compared with juvenile animals. The NO-dependent component of vasorelaxation was markedly reduced, whereas the NO-independent component was increased in adult compared to juvenile rats in both strains. The endothelial dysfunction in SHR at both ages was associated with reduction of NO-independent mechanisms. In conclusion, aging in early periods of life was associated with reduction of vascular NO production and bioavailability in both strains investigated. This reduction was however fully compensated by accentuation of NO-independent mechanisms.
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Endothelial dysfunction in experimental models of arterial hypertension: cause or consequence? BIOMED RESEARCH INTERNATIONAL 2014; 2014:598271. [PMID: 24738065 PMCID: PMC3971506 DOI: 10.1155/2014/598271] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 01/31/2014] [Indexed: 02/07/2023]
Abstract
Hypertension is a risk factor for other cardiovascular diseases and endothelial dysfunction was found in humans as well as in various commonly employed animal experimental models of arterial hypertension. Data from the literature indicate that, in general, endothelial dysfunction would not be the cause of experimental hypertension and may rather be secondary, that is, resulting from high blood pressure (BP). The initial mechanism of endothelial dysfunction itself may be associated with a lack of endothelium-derived relaxing factors (mainly nitric oxide) and/or accentuation of various endothelium-derived constricting factors. The involvement and role of endothelium-derived factors in the development of endothelial dysfunction in individual experimental models of hypertension may vary, depending on the triggering stimulus, strain, age, and vascular bed investigated. This brief review was focused on the participation of endothelial dysfunction, individual endothelium-derived factors, and their mechanisms of action in the development of high BP in the most frequently used rodent experimental models of arterial hypertension, including nitric oxide deficient models, spontaneous (pre)hypertension, stress-induced hypertension, and selected pharmacological and diet-induced models.
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Slezak P, Puzserova A, Balis P, Sestakova N, Majzunova M, Dovinova I, Kluknavsky M, Bernatova I. Genotype-related effect of crowding stress on blood pressure and vascular function in young female rats. BIOMED RESEARCH INTERNATIONAL 2014; 2014:413629. [PMID: 24729972 PMCID: PMC3963217 DOI: 10.1155/2014/413629] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 01/27/2014] [Indexed: 01/08/2023]
Abstract
This study investigated the influence of chronic crowding stress on nitric oxide (NO) production, vascular function and oxidative status in young Wistar-Kyoto (WKY), borderline hypertensive (BHR) and spontaneously hypertensive (SHR) female rats. Five-week old rats were exposed to crowding for two weeks. Crowding elevated plasma corticosterone (P<0.05) and accelerated BP (P<0.01 versus basal) only in BHR. NO production and superoxide concentration were significantly higher in the aortas of control BHR and SHR versus WKY. Total acetylcholine (ACh)-induced relaxation in the femoral artery was reduced in control SHR versus WKY and BHR, and stress did not affect it significantly in any genotype. The attenuation of ACh-induced relaxation in SHR versus WKY was associated with reduction of its NO-independent component. Crowding elevated NO production in all strains investigated but superoxide concentration was increased only in WKY, which resulted in reduced NO-dependent relaxation in WKY. In crowded BHR and SHR, superoxide concentration was either unchanged or reduced, respectively, but NO-dependent relaxation was unchanged in both BHR and SHR versus their respective control group. This study points to genotype-related differences in stress vulnerability in young female rats. The most pronounced negative influence of stress was observed in BHR despite preserved endothelial function.
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Affiliation(s)
- Peter Slezak
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
| | - Angelika Puzserova
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
| | - Peter Balis
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
| | - Natalia Sestakova
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
| | - Miroslava Majzunova
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
| | - Ima Dovinova
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
| | - Michal Kluknavsky
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
| | - Iveta Bernatova
- Institute of Normal and Pathological Physiology, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia
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