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Chen S, Chen H, Duan J, Cui L, Liu R, Xing Y. Impaired Dynamic Cerebral Autoregulation in Patients With Cerebral Venous Sinus Thrombosis: Evaluation Using Transcranial Doppler and Silent Reading Stimulation. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:2221-2226. [PMID: 37532632 DOI: 10.1016/j.ultrasmedbio.2023.07.009] [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: 03/23/2023] [Revised: 06/21/2023] [Accepted: 07/11/2023] [Indexed: 08/04/2023]
Abstract
OBJECTIVE Cerebral venous sinus thrombosis (CVST) may impair dynamic cerebral autoregulation (dCA) of the middle cerebral artery (MCA). However, most studies have focused on dCA of the MCA; a few studies are based on the posterior cerebral artery (PCA) during silent reading and neurovascular coupling (NVC). This study explored the effects of CVST on dCA of the MCA and PCA during silent reading and NVC. METHODS From January 2021 to August 2022, 60 CVST patients and 30 controls were enrolled in this study. Non-invasive continuous beat-to-beat blood pressure, cerebral blood flow velocity and other associated information on the MCA and PCA during silent reading were collected using a transcranial Doppler. NVC assessment was performed by opening and closing the eyes periodically based on voice prompts, and eye-opening visual stimulation was achieved by silently reading Chinese tourism materials. Visual stimulation signals can selectively activate Brodmann's areas 17, 18, and 19 of the occipital when reading silently with open eyes, prompting them to release neurotransmitters and dilate PCA. dCA was determined by transfer function analysis. RESULTS In dCA of the PCA during silent reading, the CVST group's very low frequency phase was lower than that of the control group (p = 0.047). In NVC, the difference in the indexes of the cerebrovascular conductance and visually evoked flow response of the CVST group were lower than those of the control group (p = 0.017 and p = 0.019, respectively). CONCLUSION Compared with the control group, dCA and NVC of the PCA during silent reading were impaired in CVST patients.
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Affiliation(s)
- Songwei Chen
- Department of Vascular Ultrasonography, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Diagnostic Center of Vascular Ultrasound, Beijing, China; Center of Vascular Ultrasonography, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Hongxiu Chen
- Department of Vascular Ultrasonography, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Diagnostic Center of Vascular Ultrasound, Beijing, China; Center of Vascular Ultrasonography, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Jiangang Duan
- Department of Emergency, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Liuping Cui
- Department of Vascular Ultrasonography, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Diagnostic Center of Vascular Ultrasound, Beijing, China; Center of Vascular Ultrasonography, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Ran Liu
- Department of Vascular Ultrasonography, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Diagnostic Center of Vascular Ultrasound, Beijing, China; Center of Vascular Ultrasonography, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Yingqi Xing
- Department of Vascular Ultrasonography, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Diagnostic Center of Vascular Ultrasound, Beijing, China; Center of Vascular Ultrasonography, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China.
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2
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Chambers LC, Yen M, Jackson WF, Dorrance AM. Female mice are protected from impaired parenchymal arteriolar TRPV4 function and impaired cognition in hypertension. Am J Physiol Heart Circ Physiol 2023; 324:H581-H597. [PMID: 36897751 PMCID: PMC10069981 DOI: 10.1152/ajpheart.00481.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/11/2023]
Abstract
Hypertension is a leading modifiable risk factor for cerebral small vessel disease. Our laboratory has shown that endothelium-dependent dilation in cerebral parenchymal arterioles (PAs) is dependent on transient receptor potential vanilloid 4 (TRPV4) activation, and this pathway is impaired in hypertension. This impaired dilation is associated with cognitive deficits and neuroinflammation. Epidemiological evidence suggests that women with midlife hypertension have an increased dementia risk that does not exist in age-matched men, though the mechanisms responsible for this are unclear. This study aimed to determine the sex differences in young, hypertensive mice to serve as a foundation for future determination of sex differences at midlife. We tested the hypothesis that young hypertensive female mice would be protected from the impaired TRPV4-mediated PA dilation and cognitive dysfunction observed in male mice. Angiotensin II (ANG II)-filled osmotic minipumps (800 ng/kg/min, 4 wk) were implanted in 16- to 19-wk-old male C56BL/6 mice. Age-matched female mice received either 800 ng/kg/min or 1,200 ng/kg/min ANG II. Sham-operated mice served as controls. Systolic blood pressure was elevated in ANG II-treated male mice and in 1,200 ng ANG II-treated female mice versus sex-matched shams. PA dilation in response to the TRPV4 agonist GSK1016790A (10-9-10-5 M) was impaired in hypertensive male mice, which was associated with cognitive dysfunction and neuroinflammation, reproducing our previous findings. Hypertensive female mice exhibited normal TRPV4-mediated PA dilation and were cognitively intact. Female mice also showed fewer signs of neuroinflammation than male mice. Determining the sex differences in cerebrovascular health in hypertension is critical for developing effective therapeutic strategies for women.NEW & NOTEWORTHY Vascular dementia is a significant public health concern, and the effect of biological sex on dementia development is not well understood. TRPV4 channels are essential regulators of cerebral parenchymal arteriolar function and cognition. Hypertension impairs TRPV4-mediated dilation and memory in male rodents. Data presented here suggest female sex protects against impaired TRPV4 dilation and cognitive dysfunction during hypertension. These data advance our understanding of the influence of biological sex on cerebrovascular health in hypertension.
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Affiliation(s)
- Laura C Chambers
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, United States
| | - Martina Yen
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, United States
| | - William F Jackson
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, United States
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, United States
- Department of Pharmacology and Toxicology, College of Human Medicine, Michigan State University, East Lansing, Michigan, United States
- Department of Pharmacology and Toxicology, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States
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Sagirov AF, Sergeev TV, Shabrov AV, Yurov AY, Guseva NL, Agapova EA. Postural influence on intracranial fluid dynamics: an overview. J Physiol Anthropol 2023; 42:5. [PMID: 37055862 PMCID: PMC10100470 DOI: 10.1186/s40101-023-00323-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 04/01/2023] [Indexed: 04/15/2023] Open
Abstract
This review focuses on the effects of different body positions on intracranial fluid dynamics, including cerebral arterial and venous flow, cerebrospinal fluid (CSF) hydrodynamics, and intracranial pressure (ICP). It also discusses research methods used to quantify these effects. Specifically, the implications of three types of body positions (orthostatic, supine, and antiorthostatic) on cerebral blood flow, venous outflow, and CSF circulation are explored, with a particular emphasis on cerebrovascular autoregulation during microgravity and head-down tilt (HDT), as well as posture-dependent changes in cerebral venous and CSF flow, ICP, and intracranial compliance (ICC). The review aims to provide a comprehensive analysis of intracranial fluid dynamics during different body positions, with the potential to enhance our understanding of intracranial and craniospinal physiology.
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Affiliation(s)
- Arlan Faritovich Sagirov
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution "Institute of Experimental Medicine", 12 Academic Pavlov St, Saint-Petersburg, 197022, Russia.
| | - Timofey Vladimirovich Sergeev
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution "Institute of Experimental Medicine", 12 Academic Pavlov St, Saint-Petersburg, 197022, Russia
| | - Aleksandr Vladimirovich Shabrov
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution "Institute of Experimental Medicine", 12 Academic Pavlov St, Saint-Petersburg, 197022, Russia
| | - Andrey Yur'evich Yurov
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution "Institute of Experimental Medicine", 12 Academic Pavlov St, Saint-Petersburg, 197022, Russia
| | - Nadezhda Leonidovna Guseva
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution "Institute of Experimental Medicine", 12 Academic Pavlov St, Saint-Petersburg, 197022, Russia
| | - Elizaveta Aleksandrovna Agapova
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution "Institute of Experimental Medicine", 12 Academic Pavlov St, Saint-Petersburg, 197022, Russia
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Johnson AC, Uhlig F, Einwag Z, Cataldo N, Erdos B. The neuroendocrine stress response impairs hippocampal vascular function and memory in male and female rats. Neurobiol Dis 2022; 168:105717. [PMID: 35385769 PMCID: PMC9018625 DOI: 10.1016/j.nbd.2022.105717] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/23/2022] [Accepted: 03/29/2022] [Indexed: 11/24/2022] Open
Abstract
Chronic psychological stress affects brain regions involved in memory such as the hippocampus and accelerates age-related cognitive decline, including in Alzheimer's disease and vascular dementia. However, little is known about how chronic stress impacts hippocampal vascular function that is critically involved in maintaining neurocognitive health that could contribute to stress-related memory dysfunction. Here, we used a novel experimental rat model that mimics the neuroendocrine and cardiovascular aspects of chronic stress to determine how the neuroendocrine components of the stress response affect hippocampal function. We studied both male and female rats to determine potential sex differences in the susceptibility of the hippocampus and its vasculature to neuroendocrine stress-induced dysfunction. We show that activation of neuroendocrine stress pathways impaired the vasoreactivity of hippocampal arterioles to mediators involved in coupling neuronal activity with local blood flow that was associated with impaired memory function. Interestingly, we found more hippocampal arteriolar dysfunction and scarcer hippocampal microvasculature in male compared to female rats that was associated with greater memory impairment, suggesting the male sex may be at increased risk of neuroendocrine-derived hippocampal dysfunction during chronic stress. Overall, this study revealed the therapeutic potential of targeting hippocampal arterioles to prevent or slow memory decline in the setting of prolonged and/or unavoidable stress.
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Affiliation(s)
- Abbie C Johnson
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA.
| | - Friederike Uhlig
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Zachary Einwag
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Noelle Cataldo
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Benedek Erdos
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
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5
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Impact of diabetes and ischemic stroke on the cerebrovasculature: A female perspective. Neurobiol Dis 2022; 167:105667. [PMID: 35227927 PMCID: PMC9615543 DOI: 10.1016/j.nbd.2022.105667] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/25/2022] [Accepted: 02/17/2022] [Indexed: 01/16/2023] Open
Abstract
There is a very complex interaction between the brain and the cerebral vasculature to meet the metabolic demands of the brain for proper function. Preservation of vascular networks and cerebrovascular function ultimately plays a key role in this intricate communication within the brain in health and disease. Experimental evidence showed that diabetes not only affects the architecture of cerebral blood arteries causing adverse remodeling, pathological neovascularization, and vasoregression, but also alters cerebrovascular function resulting in compromised myogenic reactivity and endothelial dysfunction. Coupled with the disruption of blood brain barrier (BBB) integrity, changes in blood flow and microbleeds into the brain can rapidly occur. When an ischemic insult is superimposed on this pathology, not only is the neurovascular injury greater, but repair mechanisms fail, resulting in greater physical and cognitive deficits. While clinically it is known that women suffer disproportionately from diabetes as well as ischemic stroke and post-stroke cognitive impairment, the cerebrovascular architecture, patho/physiology, as well as cerebrovascular contributions to stroke recovery in female and diabetic animal models are inadequately studied and highlighted in this review.
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Liu C, Tang W, Zhao H, Yang S, Ren Z, Li J, Chen Y, Zhao X, Xu D, Zhao Y, Shen C. The variants at FLNA and FLNB contribute to the susceptibility of hypertension and stroke with differentially expressed mRNA. THE PHARMACOGENOMICS JOURNAL 2021; 21:458-466. [PMID: 33649519 DOI: 10.1038/s41397-021-00222-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 01/18/2021] [Accepted: 02/02/2021] [Indexed: 01/31/2023]
Abstract
BACKGROUND Filamin A and filamin B were involved in vascular development and remodeling. Herein, it is important to explore the associations of FLNA and FLNB variants with hypertension and stroke. METHODS The associations of two single-nucleotide polymorphisms (SNPs) at FLNA and five SNPs at FLNB with hypertension and stroke were examined in two case-control studies and a cohort study in Chinese Han population. Risks were estimated as odds ratio (OR) and hazard ratio (HR) by Logistic and Cox regression analysis respectively. In addition, filamin B, FLNA and FLNB mRNA expression were measured. RESULTS In the case-control study of hypertension, FLNA rs2070816 (CT + TT vs. CC) and rs2070829 (CG + GG vs. CC) were significantly associated with hypertension in <55 years group (OR = 1.338, P = 0.018; OR = 1.615, P = 0.005) and FLNB rs839240 (AG + GG vs. AA) was significantly associated with hypertension in females (OR = 0.828, P = 0.041) and nonsmokers (OR = 0.829, P = 0.020). In the follow-up study, rs2070829 GG genotype carriers presented a higher risk of hypertension than CC/CG in males (HR = 1.737, P = 0.014) and smokers (HR = 1.949, P = 0.012). In the case-control study of stroke, FLNB rs1131356 variation was significantly associated with ischemic stroke (IS) and intracerebral hemorrhage (ICH), ORs of additive model were 1.342 and 1.451, with P values of 0.001 and 0.007. The FLNA transcript 2, FLNB transcript 3, transcript 4 mRNA, and filamin B expression levels were significantly different between IS cases and hypertension controls and among the genotypes of rs839240 in hypertensive individuals (P < 0.05). CONCLUSIONS Our findings support the genetic contribution of FLNA and FLNB to hypertension, and stroke with differentially mRNA expression.
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Affiliation(s)
- Chunlan Liu
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Wuzhuang Tang
- Department of Neurology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Hailong Zhao
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Song Yang
- Department of Cardiology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Zhanyun Ren
- Department of Neurology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Jie Li
- Department of Neurology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Yanchun Chen
- Department of Cardiology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Xianghai Zhao
- Department of Cardiology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Donghua Xu
- Department of Neurology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Yanping Zhao
- Department of Neurology, Affiliated Yixing People's Hospital of Jiangsu University, People's Hospital of Yixing City, Yixing, China
| | - Chong Shen
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China.
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7
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Liu C, Yin Q, Li M, Fan Y, Shen C, Yang R. ACTB Methylation in Blood as a Potential Marker for the Pre-clinical Detection of Stroke: A Prospective Nested Case-Control Study. Front Neurosci 2021; 15:644943. [PMID: 34054407 PMCID: PMC8160447 DOI: 10.3389/fnins.2021.644943] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/26/2021] [Indexed: 01/07/2023] Open
Abstract
Background Stroke is the second leading cause of death worldwide. If risk of stroke could be evaluated early or even at a preclinical stage, the mortality rate could be reduced dramatically. However, the identified genetic factors only account for 5-10% of the risk of stroke. Studies on the risk factors of stroke are urgently needed. We investigated the correlation between blood-based β-actin (ACTB) methylation and the risk of stroke in a prospective nested case-control study. Methods The methylation level of ACTB was quantitatively determined by mass spectrometry in 139 stroke cases who developed stroke within 2 years after recruitment and 147 age- and sex-matched controls who remained stroke-free in a median follow-up of 2.71 years. Results We observed a highly significant correlation between hypomethylation of one CpG site of ACTB and increased risk of stroke in an onset-time-dependent manner (for onset time ≤ 1.5 years: odds ratio (OR) per + 10% methylation = 0.76, P = 0.001; for onset time ≤ 1.32 years: OR per + 10% methylation = 0.59, P = 7.82 × 10-7; for onset time ≤ 1 year: OR per + 10% methylation = 0.43, P = 3.00 × 10-6), and the increased cumulative incidence of stroke (log-rank P = 3.13 × 10-7). Neighboring CpG sites showed an inverse correlation with age and drinking status in controls (P < 0.05) but not in stroke cases. Conclusion We firstly reported the blood-based ACTB methylation as a marker for the risk evaluation and preclinical detection of stroke, which can be further modified by age and drinking.
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Affiliation(s)
- Chunlan Liu
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Qiming Yin
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Mengxia Li
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yao Fan
- Division of Clinical Epidemiology, Affiliated Geriatric Hospital of Nanjing Medical University, Nanjing, China
| | - Chong Shen
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Rongxi Yang
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
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Kermorgant M, Nasr N, Czosnyka M, Arvanitis DN, Hélissen O, Senard JM, Pavy-Le Traon A. Impacts of Microgravity Analogs to Spaceflight on Cerebral Autoregulation. Front Physiol 2020; 11:778. [PMID: 32719617 PMCID: PMC7350784 DOI: 10.3389/fphys.2020.00778] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
It is well known that exposure to microgravity in astronauts leads to a plethora physiological responses such as headward fluid shift, body unloading, and cardiovascular deconditioning. When astronauts return to Earth, some encounter problems related to orthostatic intolerance. An impaired cerebral autoregulation (CA), which could be compromised by the effects of microgravity, has been proposed as one of the mechanisms responsible for orthostatic intolerance. CA is a homeostatic mechanism that maintains cerebral blood flow for any variations in cerebral perfusion pressure by adapting the vascular tone and cerebral vessel diameter. The ground-based models of microgravity are useful tools for determining the gravitational impact of spaceflight on human body. The head-down tilt bed rest (HDTBR), where the subject remains in supine position at -6 degrees for periods ranging from few days to several weeks is the most commonly used ground-based model of microgravity for cardiovascular deconditioning. head-down bed rest (HDBR) is able to replicate cephalic fluid shift, immobilization, confinement, and inactivity. Dry immersion (DI) model is another approach where the subject remains immersed in thermoneutral water covered with an elastic waterproof fabric separating the subject from the water. Regarding DI, this analog imitates absence of any supporting structure for the body, centralization of body fluids, immobilization and hypokinesia observed during spaceflight. However, little is known about the impact of microgravity on CA. Here, we review the fundamental principles and the different mechanisms involved in CA. We also consider the different approaches in order to assess CA. Finally, we focus on the effects of short- and long-term spaceflight on CA and compare these findings with two specific analogs to microgravity: HDBR and DI.
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Affiliation(s)
- Marc Kermorgant
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | - Nathalie Nasr
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
- Department of Neurology, Institute for Neurosciences, Toulouse University Hospital, Toulouse, France
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge University Hospital, Cambridge, United Kingdom
- Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Dina N. Arvanitis
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | - Ophélie Hélissen
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
| | - Jean-Michel Senard
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
- Department of Clinical Pharmacology, Toulouse University Hospital, Toulouse, France
| | - Anne Pavy-Le Traon
- INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France
- Department of Neurology, Institute for Neurosciences, Toulouse University Hospital, Toulouse, France
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Abstract
PURPOSE To review the recent developments on the effect of chronic high mean arterial blood pressure (MAP) on cerebral blood flow (CBF) autoregulation and supporting the notion that CBF autoregulation impairment has connection with chronic cerebral diseases. Method: A narrative review of all the relevant papers known to the authors was conducted. Results: Our understanding of the connection between cerebral perfusion impairment and chronic high MAP and cerebral disease is rapidly evolving, from cerebral perfusion impairment being the result of cerebral diseases to being the cause of cerebral diseases. We now better understand the intertwined impact of hypertension and Alzheimer's disease (AD) on cerebrovascular sensory elements and recognize cerebrovascular elements that are more vulnerable to these diseases. Conclusion: We conclude with the suggestion that the sensory elements pathology plays important roles in intertwined mechanisms of chronic high MAP and AD that impact cerebral perfusion.
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Affiliation(s)
- Noushin Yazdani
- College of Public Health, University of South Florida , Tampa, FL, USA
| | - Mark S Kindy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Biomedical Research, James A. Haley VA Medical Center , Tampa, FL, USA
| | - Saeid Taheri
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Byrd Neuroscience Institute, University of South Florida , Tampa, FL, USA
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Robison LS, Gannon OJ, Salinero AE, Zuloaga KL. Contributions of sex to cerebrovascular function and pathology. Brain Res 2018; 1710:43-60. [PMID: 30580011 DOI: 10.1016/j.brainres.2018.12.030] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/13/2022]
Abstract
Sex differences exist in how cerebral blood vessels function under both physiological and pathological conditions, contributing to observed sex differences in risk and outcomes of cerebrovascular diseases (CBVDs), such as vascular contributions to cognitive impairment and dementia (VCID) and stroke. Throughout most of the lifespan, women are protected from CBVDs; however, risk increases following menopause, suggesting sex hormones may play a significant role in this protection. The cerebrovasculature is a target for sex hormones, including estrogens, progestins, and androgens, where they can influence numerous vascular functions and pathologies. While there is a plethora of information on estrogen, the effects of progestins and androgens on the cerebrovasculature are less well-defined. Estrogen decreases cerebral tone and increases cerebral blood flow, while androgens increase tone. Both estrogens and androgens enhance angiogenesis/cerebrovascular remodeling. While both estrogens and androgens attenuate cerebrovascular inflammation, pro-inflammatory effects of androgens under physiological conditions have also been demonstrated. Sex hormones exert additional neuroprotective effects by attenuating oxidative stress and maintaining integrity and function of the blood brain barrier. Most animal studies utilize young, healthy, gonadectomized animals, which do not mimic the clinical conditions of aging individuals likely to get CBVDs. This is also concerning, as sex hormones appear to mediate cerebrovascular function differently based on age and disease state (e.g. metabolic syndrome). Through this review, we hope to inspire others to consider sex as a key biological variable in cerebrovascular research, as greater understanding of sex differences in cerebrovascular function will assist in developing personalized approaches to prevent and treat CBVDs.
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Affiliation(s)
- Lisa S Robison
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Ave, Albany, NY 12208, United States.
| | - Olivia J Gannon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Ave, Albany, NY 12208, United States.
| | - Abigail E Salinero
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Ave, Albany, NY 12208, United States.
| | - Kristen L Zuloaga
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Ave, Albany, NY 12208, United States.
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Harvey AP, Montezano AC, Hood KY, Lopes RA, Rios F, Ceravolo G, Graham D, Touyz RM. Vascular dysfunction and fibrosis in stroke-prone spontaneously hypertensive rats: The aldosterone-mineralocorticoid receptor-Nox1 axis. Life Sci 2017; 179:110-119. [PMID: 28478264 PMCID: PMC5446265 DOI: 10.1016/j.lfs.2017.05.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/21/2017] [Accepted: 05/02/2017] [Indexed: 11/28/2022]
Abstract
AIMS We questioned whether aldosterone and oxidative stress play a role in vascular damage in severe hypertension and investigated the role of Nox1 in this process. MATERIALS AND METHODS We studied mesenteric arteries, aortas and vascular smooth muscle cells (VSMC) from WKY and SHRSP rats. Vascular effects of eplerenone or canrenoic acid (CA) (mineralocorticoid receptor (MR) blockers), ML171 (Nox1 inhibitor) and EHT1864 (Rac1/2 inhibitor) were assessed. Nox1-knockout mice were also studied. Vessels and VSMCs were probed for Noxs, reactive oxygen species (ROS) and pro-fibrotic/inflammatory signaling. KEY FINDINGS Blood pressure and plasma levels of aldosterone and galectin-3 were increased in SHRSP versus WKY. Acetylcholine-induced vasorelaxation was decreased (61% vs 115%) and phenylephrine-induced contraction increased in SHRSP versus WKY (Emax 132.8% vs 96.9%, p<0.05). Eplerenone, ML171 and EHT1864 attenuated hypercontractility in SHRSP. Vascular expression of collagen, fibronectin, TGFβ, MCP-1, RANTES, MMP2, MMP9 and p66Shc was increased in SHRSP versus WKY. These changes were associated with increased ROS generation, 3-nitrotyrosine expression and Nox1 upregulation. Activation of vascular p66Shc and increased expression of Nox1 and collagen I were prevented by CA in SHRSP. Nox1 expression was increased in aldosterone-stimulated WKY VSMCs, an effect that was amplified in SHRSP VSMCs (5.2vs9.9 fold-increase). ML171 prevented aldosterone-induced VSMC Nox1-ROS production. Aldosterone increased vascular expression of fibronectin and PAI-1 in wild-type mice but not in Nox1-knockout mice. SIGNIFICANCE Our findings suggest that aldosterone, which is increased in SHRSP, induces vascular damage through MR-Nox1-p66Shc-mediated processes that modulate pro-fibrotic and pro-inflammatory signaling pathways.
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Affiliation(s)
- Adam P Harvey
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom
| | - Augusto C Montezano
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom
| | - Katie Y Hood
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom
| | - Rheure A Lopes
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom
| | - Francisco Rios
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom
| | - Graziela Ceravolo
- Department of Physiological Sciences, State University of Londrina, Londrina, Brazil
| | - Delyth Graham
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom
| | - Rhian M Touyz
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom.
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12
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Abstract
Abstract
This comprehensive review summarizes the evidence regarding use of cerebral autoregulation-directed therapy at the bedside and provides an evaluation of its impact on optimizing cerebral perfusion and associated functional outcomes. Multiple studies in adults and several in children have shown the feasibility of individualizing mean arterial blood pressure and cerebral perfusion pressure goals by using cerebral autoregulation monitoring to calculate optimal levels. Nine of these studies examined the association between cerebral perfusion pressure or mean arterial blood pressure being above or below their optimal levels and functional outcomes. Six of these nine studies (66%) showed that patients for whom median cerebral perfusion pressure or mean arterial blood pressure differed significantly from the optimum, defined by cerebral autoregulation monitoring, were more likely to have an unfavorable outcome. The evidence indicates that monitoring of continuous cerebral autoregulation at the bedside is feasible and has the potential to be used to direct blood pressure management in acutely ill patients.
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13
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Faber JE, Moore SM, Lucitti JL, Aghajanian A, Zhang H. Sex Differences in the Cerebral Collateral Circulation. Transl Stroke Res 2016; 8:273-283. [PMID: 27844273 DOI: 10.1007/s12975-016-0508-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/26/2016] [Accepted: 11/01/2016] [Indexed: 12/15/2022]
Abstract
Premenopausal women and intact female rodents sustain smaller cerebral infarctions than males. Several sex-dependent differences have been identified as potential contributors, but many questions remain unanswered. Mice exhibit wide variation in native collateral number and diameter (collateral extent) that is dependent on differences in genetic background, aging, and other comorbidities and that contributes to their also-wide differences in infarct volume. Likewise, variation in infarct volume correlates with differences in collateral-dependent blood flow in patients with acute ischemic stroke. We examined whether extent of pial collateral arterioles and posterior communicating collateral arteries (PComAs) differ depending on sex in young, aged, obese, hypertensive, and genetically different mice. We combined new data with meta-analysis of our previously published data. Females of C57BL/6J (B6) and BALB/cByJ (BC) strains sustained smaller infarctions than males after permanent MCA occlusion. This protection was unchanged in BC mice after introgression of the B6 allele of Dce1, the major genetic determinant of variation in pial collaterals among mouse strains. Consistent with this, collateral extent in these and other strains did not differ with sex. Extent of PComAs and primary cerebral arteries also did not vary with sex. No dimorphism was evident for loss of pial collateral number and/or diameter (collateral rarefaction) caused by aging, obesity, and hypertension, nor for collateral remodeling after pMCAO. However, rarefaction was greater in females with long-standing hypertension. We conclude that smaller infarct volume in female mice is not due to greater collateral extent, greater remodeling, or less rarefaction caused by aging, obesity, or hypertension.
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Affiliation(s)
- James E Faber
- Department of Cell Biology and Physiology, The McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Scott M Moore
- Department of Surgery, University of Colorado, Denver, CO, USA
| | - Jennifer L Lucitti
- Department of Cell Biology and Physiology, The McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Amir Aghajanian
- Department of Cell Biology and Physiology, The McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Hua Zhang
- Department of Cell Biology and Physiology, The McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
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14
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Qin Z, Li G, Liu N, Zhao C, Zhao H. Effect of estrogen administration on middle cerebral arterial viscoelastic properties in aged female rats. Acta Cir Bras 2016; 31:661-667. [DOI: 10.1590/s0102-865020160100000004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 09/20/2016] [Indexed: 11/21/2022] Open
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15
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Pires PW, Jackson WF, Dorrance AM. Regulation of myogenic tone and structure of parenchymal arterioles by hypertension and the mineralocorticoid receptor. Am J Physiol Heart Circ Physiol 2015; 309:H127-36. [PMID: 25910805 DOI: 10.1152/ajpheart.00168.2015] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/23/2015] [Indexed: 11/22/2022]
Abstract
Proper perfusion is vital for maintenance of neuronal homeostasis and brain function. Changes in the function and structure of cerebral parenchymal arterioles (PAs) could impair blood flow regulation and increase the risk of cerebrovascular diseases, including dementia and stroke. Hypertension alters the structure and function of large cerebral arteries, but its effects on PAs remain unknown. We hypothesized that hypertension increases myogenic tone and induces inward remodeling in PAs; we further proposed that antihypertensive therapy or mineralocorticoid receptor (MR) blockade would reverse the effects of hypertension. PAs from 18-wk-old stroke-prone spontaneously hypertensive rats (SHRSP) were isolated and cannulated in a pressure myograph. At 50-mmHg intraluminal pressure, PAs from SHRSP showed higher myogenic tone (%tone: 39.1 ± 1.9 vs. 28.7 ± 2.5%, P < 0.01) and smaller resting luminal diameter (34.7 ± 1.9 vs. 46.2 ± 2.4 μm, P < 0.01) than those from normotensive Wistar-Kyoto rats, through a mechanism that seems to require Ca(2+) influx through L-type voltage-gated Ca(2+) channels. PAs from SHRSP showed inward remodeling (luminal diameter at 60 mmHg: 55.2 ± 1.4 vs. 75.7 ± 5.1 μm, P < 0.01) and a paradoxical increase in distensibility and compliance. Treatment of SHRSP for 6 wk with antihypertensive therapy reduced PAs' myogenic tone, increased their resting luminal diameter, and prevented inward remodeling. In contrast, treatment of SHRSP for 6 wk with an MR antagonist did not reduce blood pressure or myogenic tone, but prevented inward remodeling. Thus, while hypertensive remodeling of PAs may involve the MR, myogenic tone seems to be independent of MR activity.
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Affiliation(s)
- Paulo W Pires
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and
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16
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Zacharia J, Mauban JRH, Raina H, Fisher SA, Wier WG. High vascular tone of mouse femoral arteries in vivo is determined by sympathetic nerve activity via α1A- and α1D-adrenoceptor subtypes. PLoS One 2013; 8:e65969. [PMID: 23776582 PMCID: PMC3680395 DOI: 10.1371/journal.pone.0065969] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 05/02/2013] [Indexed: 02/04/2023] Open
Abstract
Background and purpose Determining the role of vascular receptors in vivo is difficult and not readily accomplished by systemic application of antagonists or genetic manipulations. Here we used intravital microscopy to measure the contributions of sympathetic receptors, particularly α1-adrenoceptor subtypes, to contractile activation of femoral artery in vivo. Experimental approach Diameter and intracellular calcium ([Ca2+]i) in femoral arteries were determined by intravital fluorescence microscopy in mice expressing a Myosin Light Chain Kinase (MLCK) based calcium-calmodulin biosensor. Pharmacological agents were applied locally to the femoral artery to determine the contributions of vascular receptors to tonic contraction and [Ca2+]i,. Key results In the anesthetized animal, femoral arteries were constricted to a diameter equal to 54% of their passive diameter (i.e. tone = 46%). Of this total basal tone, 16% was blocked by RS79948 (0.1 µM) and thus attributable to α2-adrenoceptors. A further 46% was blocked by prazosin (0.1 µM) and thus attributable to α1-adrenoceptors. Blockade of P2X and NPY1 receptors with suramin (0.5 mM) and BIBP3226 (1.0 µM) respectively, reduced tone by a further 22%, leaving 16% of basal tone unaffected at these concentrations of antagonists. Application of RS100329 (α1A-selective antagonist) and BMY7378 (α1D-selective) decreased tone by 29% and 26%, respectively, and reduced [Ca2+]i. Chloroethylclonidine (1 µM preferential for α1B-) had no effect. Abolition of sympathetic nerve activity (hexamethonium, i.p.) reduced basal tone by 90%. Conclusion and Implications Tone of mouse femoral arteries in vivo is almost entirely sympathetic in origin. Activation of α1A- and α1D-adrenoceptors elevates [Ca2+]i and accounts for at least 55% of the tone.
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Affiliation(s)
- Joseph Zacharia
- University of Maryland, School of Medicine, Baltimore, Maryland, United States of America.
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Pires PW, Dams Ramos CM, Matin N, Dorrance AM. The effects of hypertension on the cerebral circulation. Am J Physiol Heart Circ Physiol 2013; 304:H1598-614. [PMID: 23585139 DOI: 10.1152/ajpheart.00490.2012] [Citation(s) in RCA: 250] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Maintenance of brain function depends on a constant blood supply. Deficits in cerebral blood flow are linked to cognitive decline, and they have detrimental effects on the outcome of ischemia. Hypertension causes alterations in cerebral artery structure and function that can impair blood flow, particularly during an ischemic insult or during periods of low arterial pressure. This review will focus on the historical discoveries, novel developments, and knowledge gaps in 1) hypertensive cerebral artery remodeling, 2) vascular function with emphasis on myogenic reactivity and endothelium-dependent dilation, and 3) blood-brain barrier function. Hypertensive artery remodeling results in reduction in the lumen diameter and an increase in the wall-to-lumen ratio in most cerebral arteries; this is linked to reduced blood flow postischemia and increased ischemic damage. Many factors that are increased in hypertension stimulate remodeling; these include the renin-angiotensin-aldosterone system and reactive oxygen species levels. Endothelial function, vital for endothelium-mediated dilation and regulation of myogenic reactivity, is impaired in hypertension. This is a consequence of alterations in vasodilator mechanisms involving nitric oxide, epoxyeicosatrienoic acids, and ion channels, including calcium-activated potassium channels and transient receptor potential vanilloid channel 4. Hypertension causes blood-brain barrier breakdown by mechanisms involving inflammation, oxidative stress, and vasoactive circulating molecules. This exposes neurons to cytotoxic molecules, leading to neuronal loss, cognitive decline, and impaired recovery from ischemia. As the population ages and the incidence of hypertension, stroke, and dementia increases, it is imperative that we gain a better understanding of the control of cerebral artery function in health and disease.
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Affiliation(s)
- Paulo W Pires
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
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18
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Rigsby CS, Ergul A, Dobos VP, Pollock DM, Dorrance AM. Effects of spironolactone on cerebral vessel structure in rats with sustained hypertension. Am J Hypertens 2011; 24:708-15. [PMID: 21350432 DOI: 10.1038/ajh.2011.20] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Spironolactone prevents eutrophic middle cerebral artery (MCA) remodeling in young stroke-prone spontaneously hypertensive rats (SHRSP). Clinically, it is more relevant to identify treatments that improve vessel structure after hypertension and remodeling has developed. We hypothesized that spironolactone would increase the MCA lumen diameter and reduce the wall/lumen ratio in SHRSP treated from 12 to 18 weeks of age. METHODS Twelve-week-old male SHRSP were treated with spironolactone (SHRSP + spir: 25 mg/kg/day) for 6 weeks and were compared at 18 weeks to age matched untreated SHRSP and Wistar Kyoto (WKY) rats. MCA structure was assessed by pressure myography. The WKY rats were included to provide an indication of the magnitude of the hypertensive MCA remodeling. RESULTS Spironolactone had no effect on blood pressure as measured by telemetry. MCA myogenic tone was enhanced in the SHRSP + spir. Spironolactone increased the MCA lumen diameter (SHRSP: 223.3 ± 9.7 µm, SHRSP + spir: 283.7 ± 10.1 µm, WKY: 319.5 ± 8.8 µm, analysis of variance (ANOVA) P < 0.05) and reduced the wall/lumen ratio (SHRSP: 0.107 ± 0.007, SHRSP + spir: 0.078 ± 0.006, WKY: 0.047 ± 0.002, ANOVA P < 0.05). Vessel wall stiffness was unchanged by spironolactone. Collagen 1 and 4 mRNA expression was increased in cerebral vessels from SHRSP compared to WKY rats; collagen 1 was reduced by spironolactone. Western blot analysis showed that active matrix metalloproteinase (MMP)-13 expression was increased by spironolactone treatment. The expression of intercellular adhesion molecule 1 (ICAM-1), a marker of inflammation, was increased in SHRSP and reduced by spironolactone. CONCLUSIONS These studies provide evidence that chronic mineralocorticoid receptor (MR) antagonism improves cerebral vessel structure after remodeling has developed in a model of human essential hypertension.
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19
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Impaired resistance artery function in patients with end-stage renal disease. Clin Sci (Lond) 2011; 120:525-36. [DOI: 10.1042/cs20100277] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigated an effect of uraemia on structural and functional features of human resistance vasculature. Arteries (≈ 200 μm) isolated from subcutaneous fat biopsies obtained from 35 ESRD (end-stage renal disease) patients starting peritoneal dialysis and 30 matched controls were studied using isolated small artery bioassays. Flow-mediated dilatation was attenuated in ESRD patients compared with controls. NO (nitric oxide) contribution to flow was lacking in ESRD patients, but present in the controls. ADMA (asymmetrical dimethyl L-arginine) levels were higher in the ESRD group compared with the control group. Dilatation in response to acetylcholine was reduced in ESRD patients compared with controls, but response to NO donor was similar. Expression of nitrotyrosine and heat shock proteins 70 and 27, but not 90, was increased in arteries from ESRD patients compared with controls. Arterial remodelling was absent in ESRD patients. There was no difference between the groups in myogenic tone, vascular reactivity or sensitivity to several vasoconstrictors. Arterial distensibility, reflecting passive properties of the vascular wall, was reduced in ESRD patients compared with controls. Exclusion of ESRD patients with diabetes and/or cardiovascular disease from analyses had no influence on the main findings. Thus we propose that uraemia has a strong impact on endothelial function and passive properties of the arterial wall of human peripheral resistance vasculature. The reduced contribution of NO to flow stimulus via enhanced nitrosative stress and higher plasma concentrations of ADMA may suggest potential mechanisms behind endothelial dysfunction in the resistance peripheral circulation in ESRD.
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Hypertension-induced vascular remodeling contributes to reduced cerebral perfusion and the development of spontaneous stroke in aged SHRSP rats. J Cereb Blood Flow Metab 2010; 30:827-36. [PMID: 19953101 PMCID: PMC2848710 DOI: 10.1038/jcbfm.2009.246] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Stroke in spontaneously-hypertensive, stroke-prone (SHRSP) rats is of particular interest because the pathogenesis is believed to be similar to that in the clinical setting. In this study, we employed multi-modal MRI-ASL, DWI, T(2), GRE, T(1) (pre/post contrast)-to investigate the natural history of spontaneous cerebral infarction and the specific role of cerebral perfusion in disease development. Twelve female SHRSP rats (age: approximately 1 year) were imaged within 1 to 3 days of symptom onset. The distribution of ischemic lesions was the following: 28.1% visual, 21.9% striatal, 18.8% motorsensory, 12.5% thalamic, 12.5% auditory, 3.1% frontal/prelimbic, and 3.1% multiple areas. Ischemic lesions had significantly reduced blood flow in comparison with healthy tissue. Ischemic lesions were characterized by hyperplastic, thrombosed, and compressed vessels. These findings suggest that ischemic lesion development is related to hypertension-induced vascular remodeling and persistent hypoperfusion. This model should be useful for studying the relationship between chronic hypertension and subsequent stroke, both in terms of primary and secondary prevention.
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Xiao D, Yang S, Zhang L. Prenatal cocaine exposure causes sex-dependent impairment in the myogenic reactivity of coronary arteries in adult offspring. Hypertension 2009; 54:1123-8. [PMID: 19704103 DOI: 10.1161/hypertensionaha.109.138024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cocaine abuse is a significant problem among pregnant women. The present study tested the hypothesis that prenatal cocaine exposure impairs myogenic reactivity of coronary arteries in adult offspring. Pregnant rats received cocaine (30 mg kg(-1) day(-1)) or saline from days 15 to 21 of gestational age, and experiments were conducted in 3-month-old offspring. In pressurized coronary septal arteries, the diameter and vessel wall intracellular Ca2+ concentrations were measured simultaneously in the same tissue as a function of intraluminal pressure. Cocaine did not affect KCl-induced contractions of coronary arteries in either males or females but decreased the distensibility in male vessels. In male offspring, cocaine treatment resulted in a significant decrease in pressure-dependent myogenic contractions. Inhibition of eNOS with NG-nitro-L-arginine did not alter the myogenic response in either saline control or cocaine-treated animals. In females, cocaine caused a significant increase in pressure-dependent myogenic contractions. NG-nitro-L-arginine did not affect the myogenic response in the control animals but blocked the cocaine-mediated effect. In both males and females, the pressure-induced increases in vessel wall Ca2+ concentrations were not significantly different between cocaine and saline groups. The ratio of changes in the diameter to Ca2+ concentrations in the pressurized arteries was significantly less in male but greater in female offspring after cocaine treatment. The results suggest that prenatal cocaine exposure causes reprogramming of coronary myogenic tone via changes in the Ca2+ sensitivity in a sex-dependent manner, leading to an increased risk of dysfunction of coronary autoregulation in adult offspring.
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Affiliation(s)
- DaLiao Xiao
- Center for Perinatal Biology, Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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Ahn DS, Choi SK, Kim YH, Cho YE, Shin HM, Morgan KG, Lee YH. Enhanced Stretch-Induced Myogenic Tone in the Basilar Artery of Spontaneously Hypertensive Rats. J Vasc Res 2007; 44:182-91. [PMID: 17337904 DOI: 10.1159/000100374] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Accepted: 12/20/2006] [Indexed: 11/19/2022] Open
Abstract
We investigated if the magnitude of myogenic tone in the basilar artery of SHR differs from that in WKY and, if so, whether RhoA- or PKC-dependent mechanisms were involved. Myogenic tone was developed in response to stretch. Stretch-induced myogenic contraction was significantly greater in the SHR than WKY in the presence of external Ca(2+). However, in the absence of external Ca(2+), stretch did not evoke a myogenic tone. The [Ca(2+)](i)-induced contraction was larger in SHR than WKY and the [Ca(2+)](i)-force curve was significantly shifted to the left in SHR compared to WKY. Y-27632 significantly inhibited stretch-induced myogenic tone, but the inhibitory effect was larger in the SHR than WKY. However, PKC inhibitors had no significant effect on the myogenic tone. RhoA and PKCepsilon were expressed at higher levels in the SHR compared to the WKY. RhoA and PKCalpha translocated from the cytosol to the cell membrane in response to stretch in both animals, but PKCepsilon was translocated only in SHR. Our results strongly suggest that stretch-induced myogenic tone is enhanced in SHR, and the activation of RhoA/Rho kinase plays an important role in the enhanced myogenic tone in SHR.
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Affiliation(s)
- Duck-Sun Ahn
- Department of Physiology, College of Medicine, Yonsei University, Seoul, South Korea
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Abstract
QTL mapping in humans and rats has identified hundreds of blood-pressure-related phenotypes and genomic regions; the next daunting task is gene identification and validation. The development of novel rat model systems that mimic many elements of the human disease, coupled with advances in the genomic and informatic infrastructure for rats, promise to revolutionize the hunt for genes that determine susceptibility to hypertension. Furthermore, methods are evolving that should enable the identification of candidate genes in human populations. Together with the computational reconstruction of regulatory networks, these methods provide opportunities to significantly advance our understanding of the underlying aetiology of hypertension.
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Affiliation(s)
- Allen W Cowley
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, USA.
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