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Wang JY, Song QL, Wang YL, Jiang ZM. Urinary oxygen tension and its role in predicting acute kidney injury: A narrative review. J Clin Anesth 2024; 93:111359. [PMID: 38061226 DOI: 10.1016/j.jclinane.2023.111359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 11/12/2023] [Accepted: 12/01/2023] [Indexed: 01/14/2024]
Abstract
Acute kidney injury occurs frequently in the perioperative setting. The renal medulla often endures hypoxia or hypoperfusion and is susceptible to the imbalance between oxygen supply and demand due to the nature of renal blood flow distribution and metabolic rate in the kidney. The current available evidence demonstrated that the urine oxygen pressure is proportional to the variations of renal medullary tissue oxygen pressure. Thus, urine oxygenation can be a candidate for reflecting the change of oxygen in the renal medulla. In this review, we discuss the basic physiology of acute kidney injury, as well as techniques for monitoring urine oxygen tension, confounding factors affecting the reliable measurement of urine oxygen tension, and its clinical use, highlighting its potential role in early detection and prevention of acute kidney injury.
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Affiliation(s)
- Jing-Yan Wang
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China
| | - Qi-Liang Song
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China
| | - Yu-Long Wang
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China
| | - Zong-Ming Jiang
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China.
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2
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Zhou E, Lei R, Tian X, Liu C, Guo J, Jin L, Jin H, Wang S, Cao L, Zhuoma C, Wang J, Luo B, Hu J. Association between salt sensitivity of blood pressure and the risk of hypertension in a Chinese Tibetan population. J Clin Hypertens (Greenwich) 2023; 25:453-462. [PMID: 37120829 PMCID: PMC10184482 DOI: 10.1111/jch.14663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/06/2023] [Accepted: 04/07/2023] [Indexed: 05/02/2023]
Abstract
Epidemiological studies have confirmed salt sensitivity as a crucial risk factor for the development of hypertension. However, few studies have investigated the association between salt sensitivity of blood pressure (SSBP) and hypertension in Chinese Tibetan population. Therefore, we conducted a cross-sectional study based on a Tibetan population to evaluate the association between SSBP and the risk of hypertension. Seven hundred and eighty-four participants with hypertension and 645 participants without hypertension were included from five villages in Tibetan Autonomous Region of Gannan during 2013-2014. The assessment of salt sensitivity (SS) and non-salt sensitivity (NSS) was performed according to mean arterial pressure (MAP) changes by the modified Sullivan's acute oral saline load and diuresis shrinkage test (MSAOSL-DST). Logistic regression models and restricted cubic models were used to examine the association between SSBP and hypertension. There were 554 (70.5%) salt-sensitive participants with hypertension and 412 (63.9%) salt-sensitive participants without hypertension in this study. Compared with individuals with NSS, individuals with SS had a significantly increased risk of hypertension, and the multiple-adjusted odds ratios were 2.582 with 95% confidence interval of 1.357-4.912. Furthermore, a significant linear trend was found between MAP changes and hypertension. Subgroup analyses showed significant and stronger associations between SSBP and the risk of hypertension in the older (age ≥ 55 years old), males and participants who took exercise less than 1 time per week. Our results suggest that SS is associated with an increased risk of hypertension in Tibetan population, indicating a need for clinicians dealing with SSBP to decrease the risk of hypertension.
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Affiliation(s)
- Erkai Zhou
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Ruoyi Lei
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Xiaoyu Tian
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Ce Liu
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Jingzhe Guo
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Limei Jin
- School of Public Health, Gansu University of Chinese Medicine, Lanzhou, Gansu, China
| | - Hua Jin
- School of Public Health, Gansu University of Chinese Medicine, Lanzhou, Gansu, China
| | - Shuxia Wang
- Affiliated Hospital of Gansu University of Chinese Medicine, Lanzhou, Gansu, China
| | - Liangjia Cao
- School of Public Health, Gansu University of Chinese Medicine, Lanzhou, Gansu, China
| | - Cao Zhuoma
- People's Hospital of Xiahe County, Gannan Tibetan Autonomous Prefecture, Lanzhou, Gansu, China
| | - Jianzhong Wang
- School of Tibetan Medicine, Gansu University of Chinese Medicine, Lanzhou, Gansu, China
| | - Bin Luo
- Institute of Occupational Health and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, Gansu, China
| | - Jihong Hu
- School of Public Health, Gansu University of Chinese Medicine, Lanzhou, Gansu, China
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Abstract
PURPOSE OF REVIEW In the United States (US), 46% of adults have hypertension (systolic blood pressure ≥ 130 mmHg, diastolic blood pressure ≥ 80 mmHg). Approximately, 16% of patients with hypertension have apparent treatment-resistant hypertension (aTRH) and the incidence of true resistant hypertension (RHT) is thought to be much lower (~ 2%). These patients with RHT are at a higher risk for adverse events and worse clinical outcomes. RECENT FINDINGS Although lifestyle interventions have proven to be effective as the first line of defense in treating hypertension, their role in the management of patients with RHT is not well established. Despite fewer in number, available studies examining lifestyle interventions in patients with RHT do indeed show promising results. In this review, we aim to discuss the role of common lifestyle interventions such as physical activity, exercise, weight loss, and dietary modifications on blood pressure control in patients with RHT.
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Abstract
Hypertension is a leading risk factor for disease burden worldwide. The kidneys, which have a high specific metabolic rate, play an essential role in the long-term regulation of arterial blood pressure. In this review, we discuss the emerging role of renal metabolism in the development of hypertension. Renal energy and substrate metabolism is characterized by several important and, in some cases, unique features. Recent advances suggest that alterations of renal metabolism may result from genetic abnormalities or serve initially as a physiological response to environmental stressors to support tubular transport, which may ultimately affect regulatory pathways and lead to unfavorable cellular and pathophysiological consequences that contribute to the development of hypertension.
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Affiliation(s)
- Zhongmin Tian
- grid.43169.390000 0001 0599 1243The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi China
| | - Mingyu Liang
- grid.30760.320000 0001 2111 8460Center of Systems Molecular Medicine, Department of Physiology, Medical College of Wisconsin, Milwaukee, WI USA
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Qaddumi WN, Jose PA. The Role of the Renal Dopaminergic System and Oxidative Stress in the Pathogenesis of Hypertension. Biomedicines 2021; 9:139. [PMID: 33535566 DOI: 10.3390/biomedicines9020139] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 01/11/2023] Open
Abstract
The kidney is critical in the long-term regulation of blood pressure. Oxidative stress is one of the many factors that is accountable for the development of hypertension. The five dopamine receptor subtypes (D1R–D5R) have important roles in the regulation of blood pressure through several mechanisms, such as inhibition of oxidative stress. Dopamine receptors, including those expressed in the kidney, reduce oxidative stress by inhibiting the expression or action of receptors that increase oxidative stress. In addition, dopamine receptors stimulate the expression or action of receptors that decrease oxidative stress. This article examines the importance and relationship between the renal dopaminergic system and oxidative stress in the regulation of renal sodium handling and blood pressure. It discusses the current information on renal dopamine receptor-mediated antioxidative network, which includes the production of reactive oxygen species and abnormalities of renal dopamine receptors. Recognizing the mechanisms by which renal dopamine receptors regulate oxidative stress and their degree of influence on the pathogenesis of hypertension would further advance the understanding of the pathophysiology of hypertension.
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Martín Giménez VM, Ferder L, Inserra F, García J, Manucha W. Differences in RAAS/vitamin D linked to genetics and socioeconomic factors could explain the higher mortality rate in African Americans with COVID-19. Ther Adv Cardiovasc Dis 2020; 14:1753944720977715. [PMID: 33283618 PMCID: PMC7724257 DOI: 10.1177/1753944720977715] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
COVID-19 is said to be a pandemic that does not distinguish between skin color or
ethnic origin. However, data in many parts of the world, especially in the
United States, begin to show that there is a sector of society suffering a more
significant impact from this pandemic. The Black population is more vulnerable
than the White population to infection and death by COVID-19, with hypertension
and diabetes mellitus as probable predisposing factors. Over time, multiple
disparities have been observed between the health of Black and White
populations, associated mainly with socioeconomic inequalities. However, some
mechanisms and pathophysiological susceptibilities begin to be elucidated that
are related directly to the higher prevalence of multiple diseases in the Black
population, including infection and death by COVID-19. Plasma vitamin D levels
and evolutionary adaptations of the renin-angiotensin-aldosterone system (RAAS)
in Black people differ considerably from those of other races. The role of these
factors in the development and progression of hypertension and multiple lung
diseases, among them SARS-CoV-2 infection, is well established. In this sense,
the present review attempts to elucidate the link between vitamin D and RAAS
ethnic disparities and susceptibility to infection and death by COVID-19 in
Black people, and suggests possible mechanisms for this susceptibility.
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Affiliation(s)
- Virna Margarita Martín Giménez
- Instituto de Investigaciones en Ciencias Químicas, Facultad de Ciencias Químicas y Tecnológicas, Universidad Católica de Cuyo, San Juan, Argentina
| | - León Ferder
- Universidad Maimónides, Buenos Aires, Argentina
| | | | - Joxel García
- AMBITNA, Ambitious Solutions for Health Cures, Chevy Chase, MD, USA
| | - Walter Manucha
- Instituto de Medicina y Biología Experimental de Cuyo (IMBECU), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Mendoza, Argentina.,Departamento de Patología, Facultad de Ciencias Médicas, Área de Farmacología, Universidad Nacional de Cuyo, Libertador 80, Mendoza, 5500, Argentina
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Guarnieri M, De Gasperi A, Gianni S, Baciarello M, Bellini V, Bignami E. From the Physiology to the Bedside: Fluid Therapy in Cardiac Surgery and the ICU. Curr Anesthesiol Rep 2019. [DOI: 10.1007/s40140-019-00341-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kim SR, Eirin A, Herrmann SMS, Saad A, Juncos LA, Lerman A, Textor SC, Lerman LO. Preserved endothelial progenitor cell angiogenic activity in African American essential hypertensive patients. Nephrol Dial Transplant 2019; 33:392-401. [PMID: 28402508 DOI: 10.1093/ndt/gfx032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/06/2017] [Indexed: 12/13/2022] Open
Abstract
Background African American (AA) subjects with essential hypertension (EH) have greater inflammation and cardiovascular complications than Caucasian EH. An impaired endogenous cellular repair system may exacerbate vascular injury in hypertension, yet whether these differ between AA EH and Caucasian EH remains unknown. Vascular repair by circulating endothelial progenitor cells (EPCs) is controlled by regulators of EPC mobilization, homing, adhesion and new vessel formation, but can be hindered by various cytokines. We hypothesized that EPC levels and function would be impaired in AA EH compared with Caucasian EH, in association with increased levels of inflammatory mediators and EPC regulators. Methods CD34+/KDR+ EPCs were isolated from inferior vena cava and renal vein blood samples of AA EH and Caucasian EH patients (n = 18 each) and from peripheral veins of 17 healthy volunteers (HVs) and enumerated using fluorescence-activated cell sorting. Angiogenic function of late-outgrowth endothelial cells expanded from these samples for 3 weeks was tested in vitro. Levels of inflammatory mediators, angiogenic factors and EPC regulators were measured by Luminex. Results EPC levels were decreased in both AA and Caucasian EH compared with HVs, whereas their late-outgrowth endothelial cell angiogenic function was comparable. Levels of several inflammatory mediators were elevated in AA EH compared with Caucasian EH and HVs. Contrarily, vascular endothelial growth factor and its receptor-2 were lower. EPC levels inversely correlated with blood pressure in all hypertensive patients and estimated glomerular filtration rate with inflammatory mediators only in AA EH. Conclusions Despite lower EPC numbers, decreased vascular endothelial growth factor signaling and inflammation, EPC function is preserved in AA EH compared with Caucasian EH and HVs, suggesting compensatory mechanisms for vascular repair.
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Affiliation(s)
- Seo Rin Kim
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Alfonso Eirin
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | | | - Ahmed Saad
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Luis A Juncos
- Division of Nephrology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Amir Lerman
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
| | - Stephen C Textor
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
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Eirin A, Saad A, Woollard JR, Juncos LA, Calhoun DA, Tang H, Lerman A, Textor SC, Lerman LO. Glomerular Hyperfiltration in Obese African American Hypertensive Patients Is Associated With Elevated Urinary Mitochondrial-DNA Copy Number. Am J Hypertens 2017. [PMID: 28641368 DOI: 10.1093/ajh/hpx103] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Glomerular hyperfiltration may contribute to the high incidence of renal disease in Obese African Americans essential hypertensive (ObAAEH) patients, but the precise mechanisms responsible for renal injury have not been elucidated. Mitochondria are important determinants of renal injury in hypertension, and increased levels of mitochondrial DNA (mtDNA) in the urine may indicate renal mitochondrial injury. We hypothesized that urine mtDNA copy numbers would be higher in ObAAEH compared to Caucasian essential hypertensive (CEH) patients. METHODS We prospectively measured systemic, renal vein (RV), inferior vena cava (IVC), and urinary copy number of the mtDNA genes COX3 and ND1 by quantitative-PCR in CEH and ObAAEH patients during constant sodium intake and antihypertensive regimens, and compared them with healthy volunteers (HV) (n = 23 each). RESULTS Blood pressure was similarly elevated in CEH and ObAAEH, while glomerular filtration rate (GFR) was higher and age lower in ObAAEH. Urinary (but not plasma) COX3 and ND1 were higher in CEH compared to HV, and further elevated in ObAAEH patients. COX3 and ND1 renal gradients (RV-IVC) were higher in ObAAEH vs. CEH, and their urinary levels directly correlated with GFR. In multivariate analysis, GFR remained the only predictor of elevated urinary COX3 and ND1 levels. CONCLUSIONS Urinary fragments of the mitochondrial genome are elevated in ObAAEH patients and correlate with glomerular hyperfiltration. A positive gradient across the kidney in ObAAEH suggests selective renal release. These results are consistent with mitochondrial injury that may aggravate renal damage and accelerate hypertension-related morbidity/mortality rates in ObAAEH.
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Affiliation(s)
- Alfonso Eirin
- Department of Medicine, Divisions of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Ahmed Saad
- Department of Medicine, Divisions of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - John R Woollard
- Department of Medicine, Divisions of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Luis A Juncos
- Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - David A Calhoun
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Hui Tang
- Department of Medicine, Divisions of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Amir Lerman
- Department of Medicine, Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, USA
| | - Stephen C Textor
- Department of Medicine, Divisions of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Lilach O Lerman
- Department of Medicine, Divisions of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
- Department of Medicine, Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, USA
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10
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Abstract
Chronic kidney disease (CKD) is a significant health problem associated with high morbidity and mortality. Despite significant research into various pathways involved in the pathophysiology of CKD, the therapeutic options are limited in diabetes and hypertension induced CKD to blood pressure control, hyperglycemia management (in diabetic nephropathy) and reduction of proteinuria, mainly with renin-angiotensin blockade therapy. Recently, renal oxygenation in pathophysiology of CKD progression has received a lot of interest. Several advances have been made in our understanding of the determinants and regulators of renal oxygenation in normal and diseased kidneys. The goal of this review is to discuss the alterations in renal oxygenation (delivery, consumption and tissue oxygen tension) in pre-clinical and clinical studies in diabetic and hypertensive CKD along with the underlying mechanisms and potential therapeutic options.
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Affiliation(s)
- Zhi Zhao Liu
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
| | - Alexander Bullen
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
| | - Ying Li
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
| | - Prabhleen Singh
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
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11
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Eirin A, Woollard JR, Ferguson CM, Jordan KL, Tang H, Textor SC, Lerman A, Lerman LO. The metabolic syndrome induces early changes in the swine renal medullary mitochondria. Transl Res 2017; 184:45-56.e9. [PMID: 28363084 PMCID: PMC5429873 DOI: 10.1016/j.trsl.2017.03.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 02/20/2017] [Accepted: 03/03/2017] [Indexed: 12/31/2022]
Abstract
The metabolic syndrome (MetS) is associated with nutrient surplus and kidney hyperfiltration, accelerating chronic renal failure. Mitochondria can be overwhelmed by substrate excess, leading to inefficient energy production and thereby tissue hypoxia. Mitochondrial dysfunction is emerging as an important determinant of renal damage, but whether it contributes to MetS-induced renal injury remains unknown. We hypothesized that early MetS induces kidney mitochondrial abnormalities and dysfunction, which would be notable in the vulnerable renal medulla. Pigs were studied after 16 weeks of diet-induced MetS, MetS treated for the last 4 weeks with the mitochondria-targeted peptide elamipretide (0.1 mg/kg SC q.d), and Lean controls (n = 7 each). Single-kidney renal blood flow, glomerular filtration rate, and oxygenation were measured in-vivo, whereas cortical and medullary mitochondrial structure and function and renal injurious pathways were studied ex-vivo. Blood pressure was slightly elevated in MetS pigs, and their renal blood flow and glomerular filtration rate were elevated. Blood oxygen level-dependent magnetic resonance imaging demonstrated that this was associated with medullary hypoxia, whereas cortical oxygenation remained intact. MetS decreased renal content of the inner mitochondrial membrane cardiolipin, particularly the tetra-linoleoyl (C18:2) cardiolipin species, and altered mitochondrial morphology and function, particularly in the medullary thick ascending limb. MetS also increased renal cytochrome-c-induced apoptosis, oxidative stress, and tubular injury. Chronic mitoprotection restored mitochondrial structure, ATP synthesis, and antioxidant defenses and decreased mitochondrial oxidative stress, medullary hypoxia, and renal injury. These findings implicate medullary mitochondrial damage in renal injury in experimental MetS, and position the mitochondria as a therapeutic target.
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Affiliation(s)
- Alfonso Eirin
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - John R Woollard
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | | | - Kyra L Jordan
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - Hui Tang
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - Stephen C Textor
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - Amir Lerman
- Cardiovascular Diseases, Mayo Clinic, Rochester, Minn
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn; Cardiovascular Diseases, Mayo Clinic, Rochester, Minn.
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13
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Pruijm M, Ponte B, Ackermann D, Paccaud F, Guessous I, Ehret G, Pechère-Bertschi A, Vogt B, Mohaupt MG, Martin PY, Youhanna SC, Nägele N, Vollenweider P, Waeber G, Burnier M, Devuyst O, Bochud M. Associations of Urinary Uromodulin with Clinical Characteristics and Markers of Tubular Function in the General Population. Clin J Am Soc Nephrol 2015; 11:70-80. [PMID: 26683888 DOI: 10.2215/cjn.04230415] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 09/15/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Allelic variants in UMOD, the gene coding for uromodulin, are associated with rare tubulointerstitial kidney disorders and risk of CKD and hypertension in the general population. The factors associated with uromodulin excretion in the normal population remain largely unknown, and were therefore explored in this study. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Urinary uromodulin excretion was measured using a validated ELISA in two population-based cohorts that included more than 6500 individuals. The Swiss Kidney Project on Genes in Hypertension study (SKIPOGH) included 817 adults (mean age±SD, 45±17 years) who underwent renal ultrasonography and performed a 24-hour urine collection. The Cohorte Lausannoise study included 5706 adults (mean age, 53±11 years) with fresh spot morning urine samples. We calculated eGFRs using the CKD-Epidemiology Collaboration formula and by 24-hour creatinine clearance. RESULTS In both studies, positive associations were found between uromodulin and urinary sodium, chloride, and potassium excretion and osmolality. In SKIPOGH, 24-hour uromodulin excretion (median, 41 [interquartile range, 29-57] mg/24 h) was positively associated with kidney length and volume and with creatinine excretion and urine volume. It was negatively associated with age and diabetes. Both spot uromodulin concentration and 24-hour uromodulin excretion were linearly and positively associated (multivariate analyses) with eGFR<90 ml/min per 1.73 m(2). CONCLUSION Age, creatinine excretion, diabetes, and urinary volume are independent clinical correlates of urinary uromodulin excretion. The associations of uromodulin excretion with markers of tubular functions and kidney dimensions suggest that it may reflect tubule activity in the general population.
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Affiliation(s)
- Menno Pruijm
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Belen Ponte
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Daniel Ackermann
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Fred Paccaud
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Idris Guessous
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Georg Ehret
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | | | - Bruno Vogt
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Markus G Mohaupt
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Pierre-Yves Martin
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Sonia C Youhanna
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Nadine Nägele
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Peter Vollenweider
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Gérard Waeber
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Michel Burnier
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Olivier Devuyst
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
| | - Murielle Bochud
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
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14
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Affiliation(s)
- Lilach O Lerman
- From the Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN.
| | - Stephen C Textor
- From the Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN
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15
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Khatir DS, Pedersen M, Jespersen B, Buus NH. Evaluation of Renal Blood Flow and Oxygenation in CKD Using Magnetic Resonance Imaging. Am J Kidney Dis 2015; 66:402-11. [PMID: 25618188 DOI: 10.1053/j.ajkd.2014.11.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/18/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND Animal studies suggest that progression of chronic kidney disease (CKD) is related to renal hypoxia. With renal blood supply determining oxygen delivery and sodium absorption being the main contributor to oxygen consumption, we describe the relationship between renal oxygenation, renal artery blood flow, and sodium absorption in patients with CKD and healthy controls. STUDY DESIGN Cross-sectional study. SETTING & PARTICIPANTS 62 stable patients with CKD stages 3 to 4 (mean age, 61±13 [SD] years) and 24 age- and sex-matched controls. PREDICTORS CKD versus control status. OUTCOMES Renal artery blood flow, tissue oxygenation (relative changes in deoxyhemoglobin concentration of the renal medulla [MR2*] and cortex [CR2*]), and sodium absorption. MEASUREMENTS Renal artery blood flow was determined by phase-contrast magnetic resonance imaging (MRI); MR2* and CR2* were determined by blood oxygen level-dependent MRI. Ultrafiltered and reabsorbed sodium were determined from measured glomerular filtration rate (mGFR) and 24-hour urine collections. RESULTS mGFR in patients was 37% that of controls (36±15 vs 97±23 mL/min/1.73 m(2); P < 0.001), and reabsorbed sodium was 37% that of controls (6.9 vs 19.1 mol/24 h; P < 0.001). Single-kidney patient renal artery blood flow was 72% that of controls (319 vs 443 mL/min; P < 0.001). Glomerular filtration fraction was 9% in patients and 18% in controls (P < 0.001). Patients and controls had similar CR2* (13.4 vs 13.3 s(-1)) and medullary MR2* (26.4 vs 26.5 s(-1)) values. Linear regression analysis demonstrated no associations between R2* and renal artery blood flow or sodium absorption. Increasing arterial blood oxygen tension by breathing 100% oxygen had very small effects on CR2*, but reduced MR2* in both groups. LIMITATIONS Only renal artery blood flow was determined and thus regional perfusion could not be related to CR2* or MR2*. CONCLUSIONS In CKD, reductions of mGFR and reabsorbed sodium are more than double that of renal artery blood flow, whereas cortical and medullary oxygenation are within the range of healthy persons. Reduction in glomerular filtration fraction may prevent renal hypoxia in CKD.
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Affiliation(s)
- Dinah S Khatir
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark.
| | | | - Bente Jespersen
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Niels H Buus
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Abstract
Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) has recently emerged as an important noninvasive technique to assess intrarenal oxygenation under physiologic and pathophysiologic conditions. Although this tool represents a major addition to our armamentarium of methodologies to investigate the role of hypoxia in the pathogenesis of acute kidney injury and progressive chronic kidney disease, numerous technical limitations confound interpretation of data derived from this approach. BOLD MRI has been utilized to assess intrarenal oxygenation in numerous experimental models of kidney disease and in human subjects with diabetic and nondiabetic chronic kidney disease, acute kidney injury, renal allograft rejection, contrast-associated nephropathy, and obstructive uropathy. However, confidence in conclusions based on data derived from BOLD MRI measurements will require continuing advances and technical refinements in the use of this technique.
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Affiliation(s)
- Joel Neugarten
- Renal Division, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Ladan Golestaneh
- Renal Division, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA
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Mozaffarian D, Fahimi S, Singh GM, Micha R, Khatibzadeh S, Engell RE, Lim S, Danaei G, Ezzati M, Powles J. Global sodium consumption and death from cardiovascular causes. N Engl J Med 2014; 371:624-34. [PMID: 25119608 DOI: 10.1056/nejmoa1304127] [Citation(s) in RCA: 774] [Impact Index Per Article: 77.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND High sodium intake increases blood pressure, a risk factor for cardiovascular disease, but the effects of sodium intake on global cardiovascular mortality are uncertain. METHODS We collected data from surveys on sodium intake as determined by urinary excretion and diet in persons from 66 countries (accounting for 74.1% of adults throughout the world), and we used these data to quantify the global consumption of sodium according to age, sex, and country. The effects of sodium on blood pressure, according to age, race, and the presence or absence of hypertension, were calculated from data in a new meta-analysis of 107 randomized interventions, and the effects of blood pressure on cardiovascular mortality, according to age, were calculated from a meta-analysis of cohorts. Cause-specific mortality was derived from the Global Burden of Disease Study 2010. Using comparative risk assessment, we estimated the cardiovascular effects of current sodium intake, as compared with a reference intake of 2.0 g of sodium per day, according to age, sex, and country. RESULTS In 2010, the estimated mean level of global sodium consumption was 3.95 g per day, and regional mean levels ranged from 2.18 to 5.51 g per day. Globally, 1.65 million annual deaths from cardiovascular causes (95% uncertainty interval [confidence interval], 1.10 million to 2.22 million) were attributed to sodium intake above the reference level; 61.9% of these deaths occurred in men and 38.1% occurred in women. These deaths accounted for nearly 1 of every 10 deaths from cardiovascular causes (9.5%). Four of every 5 deaths (84.3%) occurred in low- and middle-income countries, and 2 of every 5 deaths (40.4%) were premature (before 70 years of age). The rate of death from cardiovascular causes associated with sodium intake above the reference level was highest in the country of Georgia and lowest in Kenya. CONCLUSIONS In this modeling study, 1.65 million deaths from cardiovascular causes that occurred in 2010 were attributed to sodium consumption above a reference level of 2.0 g per day. (Funded by the Bill and Melinda Gates Foundation.).
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Affiliation(s)
- Dariush Mozaffarian
- From the Friedman School of Nutrition Science and Policy, Tufts University (D.M.), the Departments of Epidemiology (D.M., S.F., G.M.S., R.M., S.K., G.D.), Nutrition (D.M.), and Global Health and Population (G.D.), Harvard School of Public Health, and the Division of Cardiovascular Medicine and Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School (D.M.) - all in Boston; the Department of Public Health and Primary Care, Cambridge Institute of Public Health, Cambridge (S.F., J.P.), and the MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London (M.E.) - both in the United Kingdom; and the Institute for Health Metrics and Evaluation, University of Washington, Seattle (R.E.E., S.L.)
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18
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Affiliation(s)
- Paul M O'Connor
- Department of Physiology, Georgia Regents University, Augusta, Georgia
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Pruijm M, Hofmann L, Piskunowicz M, Muller ME, Zweiacker C, Bassi I, Vogt B, Stuber M, Burnier M. Determinants of renal tissue oxygenation as measured with BOLD-MRI in chronic kidney disease and hypertension in humans. PLoS One 2014; 9:e95895. [PMID: 24760031 PMCID: PMC3997480 DOI: 10.1371/journal.pone.0095895] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 04/01/2014] [Indexed: 11/19/2022] Open
Abstract
Experimentally renal tissue hypoxia appears to play an important role in the pathogenesis of chronic kidney disease (CKD) and arterial hypertension (AHT). In this study we measured renal tissue oxygenation and its determinants in humans using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) under standardized hydration conditions. Four coronal slices were selected, and a multi gradient echo sequence was used to acquire T2* weighted images. The mean cortical and medullary R2* values ( = 1/T2*) were calculated before and after administration of IV furosemide, a low R2* indicating a high tissue oxygenation. We studied 195 subjects (95 CKD, 58 treated AHT, and 42 healthy controls). Mean cortical R2 and medullary R2* were not significantly different between the groups at baseline. In stimulated conditions (furosemide injection), the decrease in R2* was significantly blunted in patients with CKD and AHT. In multivariate linear regression analyses, neither cortical nor medullary R2* were associated with eGFR or blood pressure, but cortical R2* correlated positively with male gender, blood glucose and uric acid levels. In conclusion, our data show that kidney oxygenation is tightly regulated in CKD and hypertensive patients at rest. However, the metabolic response to acute changes in sodium transport is altered in CKD and in AHT, despite preserved renal function in the latter group. This suggests the presence of early renal metabolic alterations in hypertension. The correlations between cortical R2* values, male gender, glycemia and uric acid levels suggest that these factors interfere with the regulation of renal tissue oxygenation.
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Affiliation(s)
- Menno Pruijm
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Lucie Hofmann
- Department of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | | | - Marie-Eve Muller
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Carole Zweiacker
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Isabelle Bassi
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Bruno Vogt
- Department of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Matthias Stuber
- Department of Radiology, University Hospital, Lausanne, Switzerland
| | - Michel Burnier
- Department of Nephrology, University Hospital, Lausanne, Switzerland
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20
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Gloviczki ML, Saad A, Textor SC. Blood oxygen level-dependent (BOLD) MRI analysis in atherosclerotic renal artery stenosis. Curr Opin Nephrol Hypertens 2013; 22:519-24. [PMID: 23917027 DOI: 10.1097/MNH.0b013e32836400b2] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE OF REVIEW Blood oxygen level-dependent MRI (BOLD MRI) is a noninvasive technique for evaluating kidney tissue oxygenation that requires no contrast exposure, with the potential to allow functional assessment in patients with atherosclerotic renal artery stenosis. Normal cortical-to-medulla oxygenation gradients are preserved in many patients treated for several years with medical antihypertensive therapy without restoring renal blood flow. The current review is of particular interest as new methods have been applied to the analyses of BOLD MRI, opening the perspective of its wider utilization in clinical practice. RECENT FINDINGS Recent findings show that more severe vascular compromise ultimately overwhelms renal adaptive changes, leading to overt cortical hypoxia and expansion of medullary hypoxic zones. 'Fractional kidney hypoxia' method of analysis, developed as an alternative method of BOLD MRI analysis, avoids the assumption of discrete cortical and medullary values and decreases the bias related to operator selection of regions of interests. SUMMARY We believe that thoughtful application and analysis of BOLD MRI can provide critical insights into changes in renal function prior to the onset of irreversible renal injury and may identify patients most likely to gain from measures to reverse or repair disorders of tissue oxygenation.
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Hall ME, Rocco MV, Morgan TM, Hamilton CA, Edwards MS, Jordan JH, Hurie JB, Hundley WG. Chronic diuretic therapy attenuates renal BOLD magnetic resonance response to an acute furosemide stimulus. J Cardiovasc Magn Reson 2014; 16:17. [PMID: 24490671 PMCID: PMC3914363 DOI: 10.1186/1532-429x-16-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 01/29/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Blood Oxygen Level Dependent (BOLD) magnetic resonance (MR) is a novel imaging tool that detects changes in tissue oxygenation. Increases in renal oxygenation in response to a standard 20 mg intravenous furosemide stimulus have been evaluated to assess kidney viability in patients with renal artery stenosis (RAS). The effect of prior exposure to furosemide on the ability of BOLD MR techniques to evaluate renal function is unknown.This study tested the hypothesis that chronic loop diuretic therapy is associated with attenuated responses in renal tissue oxygenation as measured by BOLD MR with an acute 20 mg intravenous furosemide stimulus in participants undergoing evaluation for RAS. METHODS Thirty-eight participants referred for evaluation of RAS were recruited for this study. We examined renal cortical and medullary BOLD signal (T2*) intensities before and after a 20 mg intravenous furosemide stimulus. Additionally, we measured changes in renal artery blood flow using phase contrast techniques. RESULTS After controlling for covariates age, race, gender, diabetes, glomerular filtration rate, body mass index, and stenosis severity, daily oral furosemide dose was an independent, negative predictor of renal medullary T2* response (p=0.01) to a standard 20 mg intravenous furosemide stimulus. Stenosis severity and ethnicity were also significant independent predictors of changes in T2* signal intensity in response to an acute furosemide challenge. Changes in renal blood flow in response to acute furosemide administration were correlated with changes in T2* in the renal cortex (r=0.29, p=0.03) but not the medulla suggesting changes in renal medullary oxygenation were not due to reduced renal medullary blood flow. CONCLUSIONS Chronic furosemide therapy attenuates BOLD MR responses to an acute furosemide stimulus in patients with RAS being evaluated for renal artery revascularization procedures. Thus, patients who are chronically administered loop diuretics may need a different dosing strategy to accurately detect changes in renal oxygenation with BOLD MR in response to a furosemide stimulus.
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Affiliation(s)
- Michael E Hall
- Department of Medicine, Division of Cardiology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Michael V Rocco
- Department of Medicine, Section on Nephrology, Wake Forest University School of Medicine, Winston-Salem, USA
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045, USA
| | - Timothy M Morgan
- Department of Biostatistical Sciences, Wake Forest University School of Medicine, Winston-Salem, USA
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045, USA
| | - Craig A Hamilton
- Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston-Salem, USA
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045, USA
| | - Matthew S Edwards
- Department of Vascular Surgery, Wake Forest University School of Medicine, Winston-Salem, USA
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045, USA
| | - Jennifer H Jordan
- Department of Medicine, Section on Cardiology, Wake Forest University School of Medicine, Winston-Salem, USA
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045, USA
| | - Justin B Hurie
- Department of Vascular Surgery, Wake Forest University School of Medicine, Winston-Salem, USA
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045, USA
| | - W Gregory Hundley
- Department of Medicine, Section on Cardiology, Wake Forest University School of Medicine, Winston-Salem, USA
- Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, USA
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045, USA
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Hansell P, Welch WJ, Blantz RC, Palm F. Determinants of kidney oxygen consumption and their relationship to tissue oxygen tension in diabetes and hypertension. Clin Exp Pharmacol Physiol 2013. [PMID: 23181475 DOI: 10.1111/1440-1681.12034] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The high renal oxygen (O(2) ) demand is associated primarily with tubular O(2) consumption (Qo(2) ) necessary for solute reabsorption. Increasing O(2) delivery relative to demand via increased blood flow results in augmented tubular electrolyte load following elevated glomerular filtration, which, in turn, increases metabolic demand. Consequently, elevated kidney metabolism results in decreased tissue oxygen tension. The metabolic efficiency for solute transport (Qo(2) /T(Na) ) varies not only between different nephron sites, but also under different conditions of fluid homeostasis and disease. Contributing mechanisms include the presence of different Na(+) transporters, different levels of oxidative stress and segmental tubular dysfunction. Sustained hyperglycaemia results in increased kidney Qo(2) , partly due to mitochondrial dysfunction and reduced electrolyte transport efficiency. This results in intrarenal tissue hypoxia because the increased Qo(2) is not matched by a similar increase in O(2) delivery. Hypertension leads to renal hypoxia, mediated by increased angiotensin receptor tonus and oxidative stress. Reduced uptake in the proximal tubule increases load to the thick ascending limb. There, the increased load is reabsorbed, but at greater O(2) cost. The combination of hypertension, angiotensin II and oxidative stress initiates events leading to renal damage and reduced function. Tissue hypoxia is now recognized as a unifying pathway to chronic kidney disease. We have gained good knowledge about major changes in O(2) metabolism occurring in diabetic and hypertensive kidneys. However, further efforts are needed to elucidate how these alterations can be prevented or reversed before translation into clinical practice.
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Affiliation(s)
- Peter Hansell
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
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Zhang JL, Morrell G, Rusinek H, Sigmund EE, Chandarana H, Lerman LO, Prasad PV, Niles D, Artz N, Fain S. New magnetic resonance imaging methods in nephrology. Kidney Int. 2014;85:768-778. [PMID: 24067433 PMCID: PMC3965662 DOI: 10.1038/ki.2013.361] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 02/06/2023]
Abstract
Established as a method to study anatomic changes, such as renal tumors or atherosclerotic vascular disease, magnetic resonance imaging (MRI) to interrogate renal function has only recently begun to come of age. In this review, we briefly introduce some of the most important MRI techniques for renal functional imaging, and then review current findings on their use for diagnosis and monitoring of major kidney diseases. Specific applications include renovascular disease, diabetic nephropathy, renal transplants, renal masses, acute kidney injury and pediatric anomalies. With this review, we hope to encourage more collaboration between nephrologists and radiologists to accelerate the development and application of modern MRI tools in nephrology clinics.
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Eirin A, Zhu XY, Woollard JR, Herrmann SM, Gloviczki ML, Saad A, Juncos LA, Calhoun DA, Rule AD, Lerman A, Textor SC, Lerman LO. Increased circulating inflammatory endothelial cells in blacks with essential hypertension. Hypertension 2013; 62:585-91. [PMID: 23798347 DOI: 10.1161/hypertensionaha.113.01621] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Morbidity and mortality attributable to hypertension are higher in black essential hypertensive (EH) compared with white EH patients, possibly related to differential effects on vascular injury and repair. Although circulating endothelial progenitor cells (EPCs) preserve endothelial integrity, inflammatory endothelial cells (IECs) detach from sites of injury and represent markers of vascular damage. We hypothesized that blood levels of IECs and inflammatory markers would be higher in black EH compared with white EH patients. Inferior vena cava and renal vein levels of CD34+/KDR+ (EPC) and VAP-1+ (IEC) cells were measured by fluorescence-activated cell sorting in white EH and black EH patients under fixed sodium intake and blockade of the renin-angiotensin system, and compared with systemic levels in normotensive control subjects (n=19 each). Renal vein and inferior vena cava levels of inflammatory cytokines and EPC homing factors were measured by Luminex. Blood pressure, serum creatinine, lipids, and antihypertensive medications did not differ between white and black EH patients, and EPC levels were decreased in both. Circulating IEC levels were elevated in black EH patients, and inversely correlated with EPC levels (R(2)=0.58; P=0.0001). Systemic levels of inflammatory cytokines and EPC homing factors were higher in black EH compared with white EH patients, and correlated directly with IECs. Renal vein inflammatory cytokines, EPCs, and IECs did not differ from their circulating levels. Most IECs expressed endothelial markers, fewer expressed progenitor cell markers, but none showed lymphocyte or phagocytic cell markers. Thus, increased release of cytokines and IECs in black EH patients may impair EPC reparative capacity and aggravate vascular damage, and accelerate hypertension-related complications.
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Affiliation(s)
- Alfonso Eirin
- Division of Nephrology and Hypertension, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
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