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Mitchell JW, Gillette MU. Development of circadian neurovascular function and its implications. Front Neurosci 2023; 17:1196606. [PMID: 37732312 PMCID: PMC10507717 DOI: 10.3389/fnins.2023.1196606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 08/14/2023] [Indexed: 09/22/2023] Open
Abstract
The neurovascular system forms the interface between the tissue of the central nervous system (CNS) and circulating blood. It plays a critical role in regulating movement of ions, small molecules, and cellular regulators into and out of brain tissue and in sustaining brain health. The neurovascular unit (NVU), the cells that form the structural and functional link between cells of the brain and the vasculature, maintains the blood-brain interface (BBI), controls cerebral blood flow, and surveils for injury. The neurovascular system is dynamic; it undergoes tight regulation of biochemical and cellular interactions to balance and support brain function. Development of an intrinsic circadian clock enables the NVU to anticipate rhythmic changes in brain activity and body physiology that occur over the day-night cycle. The development of circadian neurovascular function involves multiple cell types. We address the functional aspects of the circadian clock in the components of the NVU and their effects in regulating neurovascular physiology, including BBI permeability, cerebral blood flow, and inflammation. Disrupting the circadian clock impairs a number of physiological processes associated with the NVU, many of which are correlated with an increased risk of dysfunction and disease. Consequently, understanding the cell biology and physiology of the NVU is critical to diminishing consequences of impaired neurovascular function, including cerebral bleeding and neurodegeneration.
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Affiliation(s)
- Jennifer W. Mitchell
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL, United States
| | - Martha U. Gillette
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Carle-Illinois College of Medicine, University of Illinois Urbana-Champaign, Urbana, IL, United States
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Guo M, Li B, Peng Q, Yao R, Wu Y, Ma P, Du C, Liu H, Shu Z, Qin S, Yang X, Yu W. Co-exposure to particulate matter and humidity increases blood pressure in hypertensive mice via the TRPV4-cPLA 2-COX2 pathway. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 255:114800. [PMID: 36933481 DOI: 10.1016/j.ecoenv.2023.114800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 01/16/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Epidemiological studies have demonstrated that particulate matter (PM) can induce or exacerbate hypertension. High relative humidity has been associated with elevated blood pressure in certain regions. However, the coupling effect of humidity and PM on elevated blood pressure and the underlying mechanisms remain unknown. Herein, we aimed to explore the effects of exposure to PM and/or high relative humidity on hypertension, as well as elucidate underlying mechanisms. Male C57/BL6 mice were intraperitoneally administered NG-nitro-L-arginine methyl ester (L-NAME) to establish a hypertensive mouse model. The hypertensive mice were exposed to PM (0.15 mg/kg/day) and/or different relative humidities (45/90%) for eight weeks. Histopathological changes, systolic blood pressure (SBP), endothelial-derived contracting factors (thromboxane B2 [TXB2], Prostaglandin F2α [PGF2α], endothelin-1 [ET-1], and angiotensin II [Ang II]), and relaxing factors (prostaglandin I2 [PGI2] and nitric oxide [NO]) were measured to assess the effects of PM exposure and humidity on hypertension in mice. Levels of transient receptor potential vanilloid 4 (TRPV4), cytosolic phospholipase A2 (cPLA2), and cyclooxygenase 2 (COX2) were measured to explore their potential mechanisms. Herein, exposure to 90% relative humidity or PM alone had a slight but insignificant effect on hypertension. However, pathological changes and elevated blood pressure were markedly exacerbated following exposure to PM and 90% relative humidity. Levels of PGF2α, TXB2, and ET-1 were significantly increased, whereas the PGI2 level was substantially decreased. HC-067047-mediated blockade of TRPV4 suppressed TRPV4, cPLA2, and COX2 expression and effectively alleviated the increased blood pressure induced by exposure to PM and 90% relative humidity. These results indicate that 90% relative humidity and PM can activate the TRPV4-cPLA2-COX2 ion channel in the aorta, altering the endothelial-derived contracting and relaxing factors and enhancing blood pressure in hypertensive mice.
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Affiliation(s)
- Miao Guo
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China
| | - Baizhan Li
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China
| | - Qi Peng
- Xianning Engineering Research Center for Healthy Environment, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China
| | - Runming Yao
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China
| | - Yang Wu
- Xianning Engineering Research Center for Healthy Environment, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China
| | - Ping Ma
- Xianning Engineering Research Center for Healthy Environment, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China
| | - Chenqiu Du
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China
| | - Hong Liu
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China
| | - Ziyu Shu
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China
| | - Shuo Qin
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China
| | - Xu Yang
- Xianning Engineering Research Center for Healthy Environment, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China
| | - Wei Yu
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing 400045, China; National Centre for International Research of Low-carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing 400045, China.
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Ibarz-Blanch N, Morales D, Calvo E, Ros-Medina L, Muguerza B, Bravo FI, Suárez M. Role of Chrononutrition in the Antihypertensive Effects of Natural Bioactive Compounds. Nutrients 2022; 14:nu14091920. [PMID: 35565887 PMCID: PMC9103085 DOI: 10.3390/nu14091920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 04/26/2022] [Accepted: 05/02/2022] [Indexed: 12/13/2022] Open
Abstract
Hypertension (HTN) is one of the main cardiovascular risk factors and is considered a major public health problem. Numerous approaches have been developed to lower blood pressure (BP) in hypertensive patients, most of them involving pharmacological treatments. Within this context, natural bioactive compounds have emerged as a promising alternative to drugs in HTN prevention. This work reviews not only the mechanisms of BP regulation by these antihypertensive compounds, but also their efficacy depending on consumption time. Although a plethora of studies has investigated food-derived compounds, such as phenolic compounds or peptides and their impact on BP, only a few addressed the relevance of time consumption. However, it is known that BP and its main regulatory mechanisms show a 24-h oscillation. Moreover, evidence shows that phenolic compounds can interact with clock genes, which regulate the biological rhythm followed by many physiological processes. Therefore, further research might be carried out to completely elucidate the interactions along the time–nutrition–hypertension axis within the framework of chrononutrition.
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Affiliation(s)
| | | | - Enrique Calvo
- Correspondence: (E.C.); (F.I.B.); Tel.: +34-977558837 (E.C.)
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Emans TW, Janssen BJ, Joles JA, Krediet CP. Nitric Oxide Synthase Inhibition Induces Renal Medullary Hypoxia in Conscious Rats. J Am Heart Assoc 2018; 7:e009501. [PMID: 30371226 PMCID: PMC6201463 DOI: 10.1161/jaha.118.009501] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/18/2018] [Indexed: 12/14/2022]
Abstract
Background Renal hypoxia, implicated as crucial factor in onset and progression of chronic kidney disease, may be attributed to reduced nitric oxide because nitric oxide dilates vasculature and inhibits mitochondrial oxygen consumption. We hypothesized that chronic nitric oxide synthase inhibition would induce renal hypoxia. Methods and Results Oxygen-sensitive electrodes, attached to telemeters, were implanted in either renal cortex (n=6) or medulla (n=7) in rats. After recovery and stabilization, baseline oxygenation ( pO 2) was recorded for 1 week. To inhibit nitric oxide synthase, N-ω-nitro-l-arginine (L-NNA; 40 mg/kg/day) was administered via drinking water for 2 weeks. A separate group (n=8), instrumented with blood pressure telemeters, followed the same protocol. L-NNA rapidly induced hypertension (165±6 versus 108±3 mm Hg; P<0.001) and proteinuria (79±12 versus 17±2 mg/day; P<0.001). Cortical pO 2, after initially dipping, returned to baseline and then increased. Medullary pO 2 decreased progressively (up to -19±6% versus baseline; P<0.05). After 14 days of L-NNA, amplitude of diurnal medullary pO 2 was decreased (3.7 [2.2-5.3] versus 7.9 [7.5-8.4]; P<0.01), whereas amplitudes of blood pressure and cortical pO 2 were unaltered. Terminal glomerular filtration rate (1374±74 versus 2098±122 μL/min), renal blood flow (5014±336 versus 9966±905 μL/min), and sodium reabsorption efficiency (13.0±0.8 versus 22.8±1.7 μmol/μmol) decreased (all P<0.001). Conclusions For the first time, we show temporal development of renal cortical and medullary oxygenation during chronic nitric oxide synthase inhibition in unrestrained conscious rats. Whereas cortical pO 2 shows transient changes, medullary pO 2 decreased progressively. Chronic L-NNA leads to decreased renal perfusion and sodium reabsorption efficiency, resulting in progressive medullary hypoxia, suggesting that juxtamedullary nephrons are potentially vulnerable to prolonged nitric oxide depletion.
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Affiliation(s)
- Tonja W. Emans
- Internal Medicine‐NephrologyAmsterdam UMC / Academic Medical Centre at the University of AmsterdamThe Netherlands
- Nephrology and HypertensionUniversity Medical Centre UtrechtThe Netherlands
| | - Ben J. Janssen
- Pharmacology and ToxicologyMaastricht UniversityThe Netherlands
| | - Jaap A. Joles
- Nephrology and HypertensionUniversity Medical Centre UtrechtThe Netherlands
| | - C.T. Paul Krediet
- Internal Medicine‐NephrologyAmsterdam UMC / Academic Medical Centre at the University of AmsterdamThe Netherlands
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Polichnowski AJ, Licea-Vargas H, Picken M, Long J, Bisla R, Williamson GA, Bidani AK, Griffin KA. Glomerulosclerosis in the diet-induced obesity model correlates with sensitivity to nitric oxide inhibition but not glomerular hyperfiltration or hypertrophy. Am J Physiol Renal Physiol 2015; 309:F791-9. [PMID: 26109088 DOI: 10.1152/ajprenal.00211.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/19/2015] [Indexed: 12/17/2022] Open
Abstract
The diet-induced obesity (DIO) model is frequently used to examine the pathogenesis of obesity-related pathologies; however, only minimal glomerulosclerosis (GS) has been reported after 3 mo. We investigated if GS develops over longer periods of DIO and examined the potential role of hemodynamic mechanisms in its pathogenesis. Eight-week-old male obesity-prone (OP) and obesity-resistant (OR) rats (Charles River) were administered a moderately high-fat diet for 5 mo. Radiotelemetrically measured blood pressure, proteinuria, and GS were assessed. OP (n=10) rats developed modest hypertension (142±3 vs. 128±2 mmHg, P<0.05) and substantial levels of proteinuria (63±12 vs. 12±1 mg/day, P<0.05) and GS (7.7±1.4% vs. 0.4±0.2%) compared with OR rats (n=8). Potential hemodynamic mechanisms of renal injury were assessed in additional groups of OP and OR rats fed a moderately high-fat diet for 3 mo. Kidney weight (4.3±0.2 vs. 4.3±0.1 g), glomerular filtration rate (3.3±0.3 vs. 3.1±0.1 ml/min), and glomerular volume (1.9±0.1 vs. 2.0±0.1 μm3×10(-6)) were similar between OP (n=6) and OR (n=9) rats. Renal blood flow autoregulation was preserved in both OP (n=7) and OR (n=7) rats. In contrast, Nω-nitro-L-arginine methyl ester (L-NAME) administration in conscious, chronically instrumented OP (n=11) rats resulted in 15% and 39% increases in blood pressure and renal vascular resistance, respectively, and a 16% decrease in renal blood flow. Minimal effects of L-NAME were seen in OR (n=9) rats. In summary, DIO-associated GS is preceded by an increased hemodynamic sensitivity to L-NAME but not renal hypertrophy or hyperfiltration.
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Affiliation(s)
- Aaron J Polichnowski
- Department of Medicine, Loyola University, and Hines Veterans Affairs Hospital, Maywood, Illinois
| | - Hector Licea-Vargas
- Department of Medicine, Loyola University, and Hines Veterans Affairs Hospital, Maywood, Illinois
| | - Maria Picken
- Department of Pathology, Loyola University, Maywood, Illinois
| | - Jianrui Long
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois; and
| | - Rashmi Bisla
- Department of Medicine, Loyola University, and Hines Veterans Affairs Hospital, Maywood, Illinois
| | - Geoffrey A Williamson
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois; and
| | - Anil K Bidani
- Department of Medicine, Loyola University, and Hines Veterans Affairs Hospital, Maywood, Illinois
| | - Karen A Griffin
- Department of Medicine, Loyola University, and Hines Veterans Affairs Hospital, Maywood, Illinois;
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Denniff M, Turrell HE, Vanezis A, Rodrigo GC. The time-of-day variation in vascular smooth muscle contractility depends on a nitric oxide signalling pathway. J Mol Cell Cardiol 2014; 66:133-40. [DOI: 10.1016/j.yjmcc.2013.11.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 11/07/2013] [Accepted: 11/11/2013] [Indexed: 11/26/2022]
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Tsurusaki T, Sakakibara H, Aoshima Y, Yamazaki S, Sakono M, Shimoi K. Diurnal rhythmicity in biological processes involved in bioavailability of functional food factors. J Clin Biochem Nutr 2013; 52:208-14. [PMID: 23704810 PMCID: PMC3651920 DOI: 10.3164/jcbn.12-127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 02/20/2013] [Indexed: 11/22/2022] Open
Abstract
In the past few decades, many types of functional factors have been identified in dietary foods; for example, flavonoids are major groups widely distributed in the plant kingdom. However, the absorption rates of the functional food factors are usually low, and many of these are difficult to be absorbed in the intact forms because of metabolization by biological processes during absorption. To gain adequate beneficial effects, it is therefore mandatory to know whether functional food factors are absorbed in sufficient quantity, and then reach target organs while maintaining beneficial effects. These are the reasons why the bioavailability of functional food factors has been well investigated using rodent models. Recently, many of the biological processes have been reported to follow diurnal rhythms recurring every 24 h. Therefore, absorption and metabolism of functional food factors influenced by the biological processes may vary with time of day. Consequently, the evaluation of the bioavailability of functional food factors using rodent models should take into consideration the timing of consumption. In this review, we provide a perspective overview of the diurnal rhythm of biological processes involved in the bioavailability of functional food factors, particularly flavonoids.
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Affiliation(s)
- Takashi Tsurusaki
- Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibana-dai Nishi, Miyazaki 889-8526, Japan
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Heinrich UR, Helling K. Nitric oxide--a versatile key player in cochlear function and hearing disorders. Nitric Oxide 2012; 27:106-16. [PMID: 22659013 DOI: 10.1016/j.niox.2012.05.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/10/2012] [Accepted: 05/24/2012] [Indexed: 12/13/2022]
Abstract
Nitric oxide (NO) is a signaling molecule which can generally be formed by three nitric oxide synthases (NOS). Two of them, the endothelial nitric oxide synthase (eNOS) and the neural nitric oxide synthase (nNOS), are calcium/calmodulin-dependent and constitutively expressed in many cell types. Both isoforms are found in the vertebrate cochlea. The inducible nitric oxide synthase (iNOS) is independent of calcium and normally not detectable in the un-stimulated cochlea. In the inner ear, as in other tissues, NO was identified as a multitask molecule involved in various processes such as neurotransmission and neuromodulation. In addition, increasing evidence demonstrates that the NO-dependent processes of cell protection or, alternatively, cell destruction seem to depend, among other things, on changes in the local cochlear NO-concentration. These alterations can occur at the cellular level or within a distinct cell population both leading to an NO-imbalance within the hearing organ. This dysfunction can result in hearing loss or even in deafness. In cases of cochlear malfunction, regulatory systems such as the gap junction system, the blood vessels or the synaptic region might be affected temporarily or permanently by an altered NO-level. This review discusses potential cellular mechanisms how NO might contribute to different forms of hearing disorders. Approaches of NO-reduction are evaluated and the transfer of results obtained from experimental animal models to human medication is discussed.
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Affiliation(s)
- Ulf-Rüdiger Heinrich
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center of The Johannes Gutenberg-University Mainz, Germany.
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Boedtkjer E, Praetorius J, Matchkov VV, Stankevicius E, Mogensen S, Füchtbauer AC, Simonsen U, Füchtbauer EM, Aalkjaer C. Disruption of Na+,HCO₃⁻ cotransporter NBCn1 (slc4a7) inhibits NO-mediated vasorelaxation, smooth muscle Ca²⁺ sensitivity, and hypertension development in mice. Circulation 2011; 124:1819-29. [PMID: 21947296 DOI: 10.1161/circulationaha.110.015974] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Disturbances in pH affect artery function, but the mechanistic background remains controversial. We investigated whether Na(+), HCO₃- transporter NBCn1, by regulating intracellular pH(pH₁), influences artery function and blood pressure regulation. METHODS AND RESULTS Knockout of NBCn1 in mice eliminated Na+, HCO₃⁻ cotransport and caused a lower steady-state pH(i) in mesenteric artery smooth muscle and endothelial cells in situ evaluated by fluorescence microscopy. Using myography, arteries from NBCn1 knockout mice showed reduced acetylcholine-induced NO-mediated relaxations and lower rho-kinase-dependent norepinephrine-stimulated smooth muscle Ca²⁺ sensitivity. Acetylcholine-stimulated NO levels (electrode measurements) and N-nitro-l-arginine methyl ester-sensitive l-arginine conversion (radioisotope measurements) were reduced in arteries from NBCn1 knockout mice, whereas relaxation to NO-donor S-nitroso-N-acetylpenicillamine, acetylcholine-induced endothelial Ca²⁺ responses (fluorescence microscopy), and total and Ser-1177 phosphorylated endothelial NO-synthase expression (Western blot analyses) were unaffected. Reduced NO-mediated relaxations in arteries from NBCn1 knockout mice were not rescued by superoxide scavenging. Phosphorylation of myosin phosphatase targeting subunit at Thr-850 was reduced in arteries from NBCn1 knockout mice. Evaluated by an in vitro assay, rho-kinase activity was reduced at low pH. Without CO₂/HCO₃⁻, no differences in pH(i), contraction or relaxation were observed between arteries from NBCn1 knockout and wild-type mice. Based on radiotelemetry and tail-cuff measurements, NBCn1 knockout mice were mildly hypertensive at rest, displayed attenuated blood pressure responses to NO-synthase and rho-kinase inhibition and were resistant to developing hypertension during angiotensin-II infusion. CONCLUSIONS Intracellular acidification of smooth muscle and endothelial cells after knockout of NBCn1 inhibits NO-mediated and rho-kinase-dependent signaling in isolated arteries and perturbs blood pressure regulation.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark.
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Portaluppi F, Smolensky MH, Touitou Y. ETHICS AND METHODS FOR BIOLOGICAL RHYTHM RESEARCH ON ANIMALS AND HUMAN BEINGS. Chronobiol Int 2010; 27:1911-29. [DOI: 10.3109/07420528.2010.516381] [Citation(s) in RCA: 973] [Impact Index Per Article: 69.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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The role of tetrahydrobiopterin and dihydrobiopterin in ischemia/reperfusion injury when given at reperfusion. Adv Pharmacol Sci 2010; 2010:963914. [PMID: 21188246 PMCID: PMC3005837 DOI: 10.1155/2010/963914] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 03/04/2010] [Accepted: 03/17/2010] [Indexed: 11/20/2022] Open
Abstract
Reduced nitric oxide (NO) bioavailability and increased oxidative stress are major factors mediating ischemia/reperfusion (I/R) injury. Tetrahydrobiopterin (BH4) is an essential cofactor of endothelial NO synthase (eNOS) to produce NO, whereas dihydrobiopterin (BH2)
can shift the eNOS product profile from NO to superoxide, which is further converted to hydrogen peroxide (H2O2) and cause I/R injury. The effects of BH4 and BH2
on oxidative stress and postreperfused cardiac functions were examined in ex vivo myocardial and in vivo femoral I (20 min)/R (45 min) models. In femoral I/R, BH4
increased NO and decreased H2O2 releases relative to saline control, and these effects correlated with improved postreperfused cardiac function. By contrast, BH2
decreased NO release relative to the saline control, but increased H2O2 release similar to the saline control, and these effects correlated with compromised postreperfused cardiac function. In conclusion, these results suggest that promoting eNOS coupling to produce NO and decrease H2O2 may be a key mechanism to restore postreperfused organ function during early reperfusion.
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Grundt A, Grundt C, Gorbey S, Thomas MA, Lemmer B. Strain-dependent differences of restraint stress-induced hypertension in WKY and SHR. Physiol Behav 2009; 97:341-6. [DOI: 10.1016/j.physbeh.2009.02.029] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 02/18/2009] [Accepted: 02/26/2009] [Indexed: 11/25/2022]
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