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Gritter M, Wei KY, Wouda RD, Musterd-Bhaggoe UM, Dijkstra KL, Kers J, Ramakers C, Vogt L, de Borst MH, Danser AHJ, Hoorn EJ, Rotmans JI. Chronic kidney disease increases the susceptibility to negative effects of low and high potassium intake. Nephrol Dial Transplant 2024; 39:795-807. [PMID: 37813819 PMCID: PMC11045281 DOI: 10.1093/ndt/gfad220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Indexed: 10/11/2023] Open
Abstract
BACKGROUND Dietary potassium (K+) has emerged as a modifiable factor for cardiovascular and kidney health in the general population, but its role in people with chronic kidney disease (CKD) is unclear. Here, we hypothesize that CKD increases the susceptibility to the negative effects of low and high K+ diets. METHODS We compared the effects of low, normal and high KChloride (KCl) diets and a high KCitrate diet for 4 weeks in male rats with normal kidney function and in male rats with CKD using the 5/6th nephrectomy model (5/6Nx). RESULTS Compared with rats with normal kidney function, 5/6Nx rats on the low KCl diet developed more severe extracellular and intracellular K+ depletion and more severe kidney injury, characterized by nephromegaly, infiltration of T cells and macrophages, decreased estimated glomerular filtration rate and increased albuminuria. The high KCl diet caused hyperkalemia, hyperaldosteronism, hyperchloremic metabolic acidosis and severe hypertension in 5/6Nx but not in sham rats. The high KCitrate diet caused hypochloremic metabolic alkalosis but attenuated hypertension despite higher abundance of the phosphorylated sodium chloride cotransporter (pNCC) and similar levels of plasma aldosterone and epithelial sodium channel abundance. All 5/6Nx groups had more collagen deposition than the sham groups and this effect was most pronounced in the high KCitrate group. Plasma aldosterone correlated strongly with kidney collagen deposition. CONCLUSIONS CKD increases the susceptibility to negative effects of low and high K+ diets in male rats, although the injury patterns are different. The low K+ diet caused inflammation, nephromegaly and kidney function decline, whereas the high K+ diet caused hypertension, hyperaldosteronism and kidney fibrosis. High KCitrate attenuated the hypertensive but not the pro-fibrotic effect of high KCl, which may be attributable to K+-induced aldosterone secretion. Our data suggest that especially in people with CKD it is important to identify the optimal threshold of dietary K+ intake.
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Affiliation(s)
- Martin Gritter
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Kuang-Yu Wei
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Rosa D Wouda
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Usha M Musterd-Bhaggoe
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Kyra L Dijkstra
- Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jesper Kers
- Pathology, Leiden University Medical Center, Leiden, The Netherlands
- Pathology, Amsterdam University Medical Center, Amsterdam, The Netherlands
- Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Liffert Vogt
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Martin H de Borst
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander H J Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Ewout J Hoorn
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joris I Rotmans
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
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Lee SY, Park JT, Joo YS, Yoo TH, Lee J, Chung W, Kim YS, Kim SW, Oh KH, Ahn C, Kang SW, Choi KH, Han SH. Association between the transtubular potassium gradient and progression of chronic kidney disease: results from KNOW-CKD. J Nephrol 2021; 34:2063-2072. [PMID: 33755931 DOI: 10.1007/s40620-021-01019-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/03/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND The transtubular potassium gradient which reflects potassium secretion by the kidney through the cortical collecting duct, has not yet been tested as a surrogate marker of kidney function decline. Here, we investigate the relationship between the transtubular potassium gradient and chronic kidney disease (CKD) progression. METHODS We studied 1672 patients from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD) cohort. The transtubular potassium gradient was calculated using a standard equation. The study endpoint was CKD progression, defined as a composite of a ≥ 50% decrease in estimated glomerular filtration rate (eGFR) from baseline values or end-stage kidney disease. RESULTS During a median follow-up of 4.1 years (7149 person-years), 441 participants reached the endpoint. In cause-specific competing risk analysis, the highest tertile was associated with a significantly lower risk of an adverse kidney outcome compared with the lowest tertile [hazard ratio (HR), 0.73; 95% confidence interval (CI), 0.55-0.97]. When the transtubular potassium gradient was treated as a continuous variable, an increase of 1 in the transtubular potassium gradient was associated with a 6% lower risk of CKD progression (95% CI, 0.90-0.99). This association was particularly evident in patients with an eGFR ≥ 45 mL/min/1.73 m2. A time-updated transtubular potassium gradient model showed similar results. The predictive performance of the transtubular potassium gradient was significantly less than that of the eGFR, but similar to that of proteinuria, serum bicarbonate, and urine osmolality. CONCLUSIONS A higher transtubular potassium gradient is associated with a significantly lower risk of CKD progression, suggesting that it may offer insights into the prognosis of CKD.
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Affiliation(s)
- Seon Yeong Lee
- Department of Internal Medicine, Institute of Kidney Disease Research, College of Medicine, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea
| | - Jung Tak Park
- Department of Internal Medicine, Institute of Kidney Disease Research, College of Medicine, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea
| | - Young Su Joo
- Division of Nephrology, Department of Internal Medicine, Myongji Hospital, Goyang, Republic of Korea
| | - Tae-Hyun Yoo
- Department of Internal Medicine, Institute of Kidney Disease Research, College of Medicine, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea
| | - Joongyub Lee
- Department of Prevention and Management, Inha University School of Medicine, Incheon, Republic of Korea
| | - Wookyung Chung
- Department of Internal Medicine, Gil Hospital, Gachon University, Incheon, South Korea
| | - Yong-Soo Kim
- Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea
| | - Soo Wan Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Kook-Hwan Oh
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Curie Ahn
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Shin-Wook Kang
- Department of Internal Medicine, Institute of Kidney Disease Research, College of Medicine, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea
| | - Kyu Hun Choi
- Department of Internal Medicine, Institute of Kidney Disease Research, College of Medicine, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea
| | - Seung Hyeok Han
- Department of Internal Medicine, Institute of Kidney Disease Research, College of Medicine, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea.
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Wei KY, Gritter M, Vogt L, de Borst MH, Rotmans JI, Hoorn EJ. Dietary potassium and the kidney: lifesaving physiology. Clin Kidney J 2020; 13:952-968. [PMID: 33391739 PMCID: PMC7769543 DOI: 10.1093/ckj/sfaa157] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Indexed: 02/07/2023] Open
Abstract
Potassium often has a negative connotation in Nephrology as patients with chronic kidney disease (CKD) are prone to develop hyperkalaemia. Approaches to the management of chronic hyperkalaemia include a low potassium diet or potassium binders. Yet, emerging data indicate that dietary potassium may be beneficial for patients with CKD. Epidemiological studies have shown that a higher urinary potassium excretion (as proxy for higher dietary potassium intake) is associated with lower blood pressure (BP) and lower cardiovascular risk, as well as better kidney outcomes. Considering that the composition of our current diet is characterized by a high sodium and low potassium content, increasing dietary potassium may be equally important as reducing sodium. Recent studies have revealed that dietary potassium modulates the activity of the thiazide-sensitive sodium-chloride cotransporter in the distal convoluted tubule (DCT). The DCT acts as a potassium sensor to control the delivery of sodium to the collecting duct, the potassium-secreting portion of the kidney. Physiologically, this allows immediate kaliuresis after a potassium load, and conservation of potassium during potassium deficiency. Clinically, it provides a novel explanation for the inverse relationship between dietary potassium and BP. Moreover, increasing dietary potassium intake can exert BP-independent effects on the kidney by relieving the deleterious effects of a low potassium diet (inflammation, oxidative stress and fibrosis). The aim of this comprehensive review is to link physiology with clinical medicine by proposing that the same mechanisms that allow us to excrete an acute potassium load also protect us from hypertension, cardiovascular disease and CKD.
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Affiliation(s)
- Kuang-Yu Wei
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Internal Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Liffert Vogt
- Department of Internal Medicine, Division of Nephrology, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Joris I Rotmans
- Department of Internal Medicine, Division of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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Hoorn EJ, Gritter M, Cuevas CA, Fenton RA. Regulation of the Renal NaCl Cotransporter and Its Role in Potassium Homeostasis. Physiol Rev 2020; 100:321-356. [DOI: 10.1152/physrev.00044.2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Daily dietary potassium (K+) intake may be as large as the extracellular K+ pool. To avoid acute hyperkalemia, rapid removal of K+ from the extracellular space is essential. This is achieved by translocating K+ into cells and increasing urinary K+ excretion. Emerging data now indicate that the renal thiazide-sensitive NaCl cotransporter (NCC) is critically involved in this homeostatic kaliuretic response. This suggests that the early distal convoluted tubule (DCT) is a K+ sensor that can modify sodium (Na+) delivery to downstream segments to promote or limit K+ secretion. K+ sensing is mediated by the basolateral K+ channels Kir4.1/5.1, a capacity that the DCT likely shares with other nephron segments. Thus, next to K+-induced aldosterone secretion, K+ sensing by renal epithelial cells represents a second feedback mechanism to control K+ balance. NCC’s role in K+ homeostasis has both physiological and pathophysiological implications. During hypovolemia, NCC activation by the renin-angiotensin system stimulates Na+ reabsorption while preventing K+ secretion. Conversely, NCC inactivation by high dietary K+ intake maximizes kaliuresis and limits Na+ retention, despite high aldosterone levels. NCC activation by a low-K+ diet contributes to salt-sensitive hypertension. K+-induced natriuresis through NCC offers a novel explanation for the antihypertensive effects of a high-K+ diet. A possible role for K+ in chronic kidney disease is also emerging, as epidemiological data reveal associations between higher urinary K+ excretion and improved renal outcomes. This comprehensive review will embed these novel insights on NCC regulation into existing concepts of K+ homeostasis in health and disease.
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Affiliation(s)
- Ewout J. Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Catherina A. Cuevas
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Robert A. Fenton
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
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5
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Gritter M, Rotmans JI, Hoorn EJ. Role of Dietary K + in Natriuresis, Blood Pressure Reduction, Cardiovascular Protection, and Renoprotection. Hypertension 2019; 73:15-23. [PMID: 30571564 DOI: 10.1161/hypertensionaha.118.11209] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Martin Gritter
- From the Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands (M.G., E.J.H.)
| | - Joris I Rotmans
- Department of Internal Medicine-Nephrology, Leiden University Medical Center, the Netherlands (J.I.R.)
| | - Ewout J Hoorn
- From the Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands (M.G., E.J.H.)
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Hu D, Dong R, Yang Y, Chen Z, Tang Y, Fu M, Wang DW, Xu X, Tu L. Human kallikrein overexpression alleviates cardiac aging by alternatively regulating macrophage polarization in aged rats. FASEB J 2019; 33:8436-8452. [PMID: 30995868 DOI: 10.1096/fj.201802371rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cardiac aging is characterized by myocardial hypertrophy, fibrosis, and diastolic dysfunction. Human kallikrein (hKLK1) protects against fibrosis in various pathogenic states. However, the effects of hKLK1 overexpression on cardiac aging-related fibrosis and the underlying mechanisms remain unknown. Moreover, the role of hKLK1 in regulating macrophage function leading to cardiac fibrosis has not been investigated. Thus, in this study, we determined the effects of hKLK1 on cardiac aging and explored the mechanisms through which hKLK1 regulated aging-related fibrosis. Echocardiographic measurements showed that aging caused significant alternations in cardiac morphology, hypertrophy, and fibrosis in rats, and hKLK1 overexpression protected against aging-induced cardiac dysfunction. Compared with wild-type hearts, the hKLK1 transgene decreased the expression of monocyte chemoattractant protein 1 and suppressed mitochondrial dysfunction and excess oxidative stress, leading to decreased recruitment and retention of alternatively activated (M2) macrophages and reduced secretion of profibrotic cytokines mediated by the TGF-β1-Smad3 signaling pathway in hearts of aging rats. Furthermore, these cardioprotective effects of hKLK1 overexpression were associated with the Janus kinase-signal transducer and activator of transcription 3 signaling pathway. H2O2-induced senescence promoted the differentiation of RAW264.7 cells into M2-type cells induced by IL-4 treatment. Bradykinin treatment relieved the migratory capacity of macrophages induced by H2O2. Thus, hKLK1 overexpression reduced cardiac fibrosis and improved aging-related cardiac dysfunction through reduced shift of macrophages to M2 macrophages, indicating that hKLK1 may alleviate aging-related cardiac dysfunction.-Hu, D., Dong, R., Yang, Y., Chen, Z., Tang, Y., Fu, M., Wang, D. W., Xu, X., Tu, L. Human kallikrein overexpression alleviates cardiac aging by alternatively regulating macrophage polarization in aged rats.
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Affiliation(s)
- Danli Hu
- Department of Geriatric Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,National Clinical Research Center of Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences-Peking Union Medical College, Beijing, China
| | - Ruolan Dong
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Yang
- Department of Geriatric Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhihui Chen
- Department of Geriatric Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Tang
- Department of Geriatric Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Menglu Fu
- Department of Geriatric Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dao Wen Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xizhen Xu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Tu
- Department of Geriatric Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Thio CHL, Vart P, Kieneker LM, Snieder H, Gansevoort RT, Bültmann U. Educational level and risk of chronic kidney disease: longitudinal data from the PREVEND study. Nephrol Dial Transplant 2018; 35:1211-1218. [DOI: 10.1093/ndt/gfy361] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/23/2018] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
The longitudinal association between low education and chronic kidney disease (CKD) and its underlying mechanisms is poorly characterized. We therefore examined the association of low education with incident CKD and change in kidney function, and explored potential mediators of this association.
Methods
We analysed data on 6078 participants from the community-based Prevention of Renal and Vascular End-stage Disease study. Educational level was categorized into low, medium and high (< secondary, secondary/equivalent, > secondary schooling, respectively). Kidney function was assessed by estimating glomerular filtration rate (eGFR) by serum creatinine and cystatin C at five examinations during ∼11 years of follow-up. Incident CKD was defined as new-onset eGFR <60 mL/min/1.73 m2 and/or urinary albumin ≥30 mg/24 h in those free of CKD at baseline. We estimated main effects with Cox regression and linear mixed models. In exploratory causal mediation analyses, we examined mediation by several potential risk factors.
Results
Incident CKD was observed in 861 (17%) participants. Lower education was associated with higher rates of incident CKD [low versus high education; hazard ratio (HR) (95% CI) 1.25 (1.05–1.48), Ptrend = 0.009] and accelerated eGFR decline [B (95% CI) −0.15 (−0.21 to −0.09) mL/min/1.73 m2/year, Ptrend < 0.001]. The association between education and incident CKD was mediated by smoking, potassium excretion, body mass index (BMI), waist-to-hip ratio (WHR) and hypertension. Analysis on annual eGFR change in addition suggested mediation by magnesium excretion, protein intake and diabetes.
Conclusions
In the general population, we observed an inverse association of educational level with CKD. Diabetes and the modifiable risk factors smoking, poor diet, BMI, WHR and hypertension are suggested to underlie this association. These findings provide support for targeted preventive policies to reduce socioeconomic disparities in kidney disease.
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Affiliation(s)
- Chris H L Thio
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Priya Vart
- Department of Epidemiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lyanne M Kieneker
- Department of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ron T Gansevoort
- Department of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ute Bültmann
- Department of Health Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Yeung SMH, Vogt L, Rotmans JI, Hoorn EJ, de Borst MH. Potassium: poison or panacea in chronic kidney disease? Nephrol Dial Transplant 2018; 34:175-180. [DOI: 10.1093/ndt/gfy329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/20/2018] [Indexed: 11/15/2022] Open
Affiliation(s)
- Stanley M H Yeung
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Liffert Vogt
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Joris I Rotmans
- Department of Internal Medicine (Nephrology), Leiden University Medical Center, Leiden, The Netherlands
| | - Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Luan Y, Ruan Y, Wang T, Zhuan L, Wen Z, Chen R, Zhang Y, Cui K, Yang J, Wang S, Liu J, Ye Z, Wang D. Preserved Erectile Function in the Aged Transgenic Rat Harboring Human Tissue Kallikrein 1. J Sex Med 2017; 13:1311-1322. [PMID: 27555503 DOI: 10.1016/j.jsxm.2016.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/07/2016] [Accepted: 07/09/2016] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Human tissue kallikrein 1 (hKLK1) has enormous potential for the protection of vasodilation and endothelial function in the cardiovascular system. Our previous study proved the decreased expression of kallikrein 1 in the corpus cavernosum (CC) of aged rats, but the role of kallikrein 1 in age-related erectile dysfunction remains unknown. AIM To explore the effect and underlying mechanisms of hKLK1 on age-related erectile dysfunction. METHODS Male wild-type Sprague-Dawley rats (WTR) and transgenic rats harboring the hKLK1 gene (TGR) were fed to 4 and 27 months of age, respectively, and divided into four groups: young WTR (yWTR) as the control, young TGR (yTGR), aged WTR (aWTR), and aged TGR (aTGR). Rats' erectile function was evaluated by the cavernous nerve electrostimulation method. Then, CCs were collected for verification of hKLK1 followed by measurement of nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) and RhoA-Rho-kinase (ROCK) signaling activities. Masson trichrome staining and terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling assay were conducted to evaluate penile fibrosis and apoptosis. MAIN OUTCOME MEASURES Erectile response, NO-cGMP and RhoA-ROCK pathway-related indices, ratio of smooth muscle to collagen, and apoptosis index. RESULTS The hKLK1 alleviated the decrease of erectile function in the aWTR group. Endothelial NO synthase (eNOS) and phospho-eNOS(Ser1177) expressions, NO synthase activity, and NO and cGMP levels were decreased, whereas phospho-eNOS(Thr495), L-type Ca(2+) channel, RhoA, ROCK1, ROCK2, and transforming growth factor β1 proteins were increased in the CCs of the aWTR group compared with the control yWTR group. These changes were obviously mitigated in the aTGR group. Moreover, hKLK1 prevented the sharp decrease of the ratio of smooth muscle to collagen and the increase of the apoptosis index in the CCs of the aWTR group. CONCLUSION These results suggest that hKLK1 could play a preventive role in age-related erectile dysfunction by activation of the NO-cGMP pathway and inhibition of the RhoA-ROCK pathway and by antitissue fibrotic and apoptotic effects.
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Affiliation(s)
- Yang Luan
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yajun Ruan
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Tao Wang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Li Zhuan
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zheng Wen
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ruibao Chen
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yan Zhang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Kai Cui
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jun Yang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shaogang Wang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jihong Liu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Zhangqun Ye
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Daowen Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Plasma potassium, diuretic use and risk of developing chronic kidney disease in a predominantly White population. PLoS One 2017; 12:e0174686. [PMID: 28346526 PMCID: PMC5367826 DOI: 10.1371/journal.pone.0174686] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/12/2017] [Indexed: 02/08/2023] Open
Abstract
Objective Both hypokalemia and hyperkalemia are associated with disease progression in patients with chronic kidney disease (CKD). It is unclear whether similar associations are present in the general population. Our aim was to examine the association of plasma potassium with risk of developing CKD and the role of diuretics in this association in a population-based cohort. Research design and methods We studied 5,130 subjects free of CKD at baseline of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study, a prospective, population-based cohort of Dutch men and women aged 28–75 years. Hypokalemia was defined as plasma potassium <3.5 mmol/L, and hyperkalemia as plasma potassium ≥5.0 mmol/L. Risk of CKD was defined as de novo development of eGFR <60 ml/min/1.73m2 and/or albuminuria >30 mg/24h. Results Mean baseline plasma potassium was 4.4±0.3 mmol/L. The prevalences of hypokalemia and hyperkalemia were 0.5% and 3.8%, respectively; 3.0% of the subjects used diuretics. During a median follow-up of 10.3 years (interquartile range: 6.3–11.4 years), 753 subjects developed CKD. The potassium-CKD association was modified by diuretic use (Pinteraction = 0.02). Both hypokalemia without (HR, 7.74, 95% CI, 3.43–17.48) or with diuretic use (HR, 4.32, 95% CI, 1.77–10.51) were associated with an increased CKD risk as compared to plasma potassium 4.0–4.4 mmol/L without diuretic use. Plasma potassium concentrations ≥3.5 mmol/L were associated with an increased CKD risk among subjects using diuretics (Ptrend = 0.01) but not among subjects not using diuretics (Ptrend = 0.74). Conclusion In this population-based cohort, hypokalemia was associated with an increased CKD risk, regardless of diuretic use. In the absence of hypokalemia, plasma potassium was not associated with an increased CKD risk, except among subjects using diuretics.
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Activation of TRPV4 by dietary apigenin antagonizes renal fibrosis in deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Clin Sci (Lond) 2017; 131:567-581. [PMID: 28143892 DOI: 10.1042/cs20160780] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 12/22/2016] [Accepted: 01/31/2017] [Indexed: 01/28/2023]
Abstract
Hypertension-induced renal fibrosis contributes to the progression of chronic kidney disease, and apigenin, an anti-hypertensive flavone that is abundant in celery, acts as an agonist of transient receptor potential vanilloid 4 (TRPV4). However, whether apigenin reduces hypertension-induced renal fibrosis, as well as the underlying mechanism, remains elusive. In the present study, the deoxycorticosterone acetate (DOCA)-salt hypertension model was established in male Sprague-Dawley rats that were treated with apigenin or vehicle for 4 weeks. Apigenin significantly attenuated the DOCA-salt-induced structural and functional damage to the kidney, which was accompanied by reduced expression of transforming growth factor-β1 (TGF-β1)/Smad2/3 signaling pathway and extracellular matrix proteins. Immunochemistry, cell-attached patch clamp and fluorescent Ca2+ imaging results indicated that TRPV4 was expressed and activated by apigenin in both the kidney and renal cells. Importantly, knockout of TRPV4 in mice abolished the beneficial effects of apigenin that were observed in the DOCA-salt hypertensive rats. Additionally, apigenin directly inhibited activation of the TGF-β1/Smad2/3 signaling pathway in different renal tissues through activation of TRPV4 regardless of the type of pro-fibrotic stimulus. Moreover, the TRPV4-mediated intracellular Ca2+ influx activated the AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) pathway, which inhibited the TGF-β1/Smad2/3 signaling pathway. In summary, dietary apigenin has beneficial effects on hypertension-induced renal fibrosis through the TRPV4-mediated activation of AMPK/SIRT1 and inhibition of the TGF-β1/Smad2/3 signaling pathway. This work suggests that dietary apigenin may represent a promising lifestyle modification for the prevention of hypertension-induced renal damage in populations that consume a high-sodium diet.
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Eisenga MF, Kieneker LM, Soedamah-Muthu SS, van den Berg E, Deetman PE, Navis GJ, Gans RO, Gaillard CA, Bakker SJ, Joosten MM. Urinary potassium excretion, renal ammoniagenesis, and risk of graft failure and mortality in renal transplant recipients. Am J Clin Nutr 2016; 104:1703-1711. [PMID: 27935524 DOI: 10.3945/ajcn.116.134056] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 10/11/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Renal transplant recipients (RTRs) have commonly been urged to limit their potassium intake during renal insufficiency and may adhere to this principle after transplantation. Importantly, in experimental animal models, low dietary potassium intake induces kidney injury through stimulation of ammoniagenesis. In humans, low potassium intake is an established risk factor for high blood pressure. OBJECTIVE We hypothesized that low 24-h urinary potassium excretion [UKV; urinary potassium concentration × volume], the gold standard for assessment of dietary potassium intake, represents a risk factor for graft failure and mortality in RTRs. In secondary analyses, we aimed to investigate whether these associations could be explained by ammoniagenesis, plasma potassium, or blood pressure. DESIGN In a prospective cohort of 705 RTRs, we assessed dietary potassium intake by a single 24-h UKV and food-frequency questionnaires. Cox regression analyses were used to investigate prospective associations with outcome. RESULTS We included 705 stable RTRs (mean ± SD age: 53 ± 13 y; 57% men) at 5.4 y (IQR: 1.9-12.0 y) after transplantation and 253 kidney donors. Mean ± SD UKV was 73 ± 24 mmol/24 h in RTRs compared with 85 ± 25 mmol/24 h in kidney donors. During follow-up for 3.1 y (IQR: 2.7-3.9 y), 45 RTRs developed graft failure and 83 died. RTRs in the lowest sex-specific tertile of UKV (women, <55 mmol/24 h; men, <65 mmol/24 h) had an increased risk of graft failure (HR: 3.70; 95% CI: 1.64, 8.34) and risk of mortality (HR; 2.66; 95% CI: 1.53, 4.61), independent of potential confounders. In causal path analyses, 24-h urinary ammonia excretion, plasma potassium, and blood pressure did not affect these associations. CONCLUSIONS Our results indicate that low UKV is associated with a higher risk of graft failure and mortality in RTRs. Specific attention for adequate potassium intake after transplantation seems warranted. This trial was registered at clinicaltrials.gov as NCT02811835.
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Affiliation(s)
| | | | | | - Else van den Berg
- Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands; and
| | | | | | - Reinold Ob Gans
- Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands; and
| | | | - Stephan Jl Bakker
- Departments of Nephrology and.,Top Institute Food and Nutrition, Wageningen, Netherlands
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13
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Kieneker LM, Bakker SJL, de Boer RA, Navis GJ, Gansevoort RT, Joosten MM. Low potassium excretion but not high sodium excretion is associated with increased risk of developing chronic kidney disease. Kidney Int 2016; 90:888-96. [PMID: 27575557 DOI: 10.1016/j.kint.2016.07.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/10/2016] [Accepted: 07/07/2016] [Indexed: 01/05/2023]
Abstract
It is unclear whether sodium and potassium intake is relevant to the development of chronic kidney disease (CKD) in the general population. Our aim was to examine the associations of urinary sodium (UNaV) and potassium excretion (UKV), as estimates of intake, with risk of developing CKD in a population-based cohort. We studied 5315 individuals free of CKD at baseline of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study, a prospective, population-based cohort of Dutch men and women aged 28 to 75 years. UNaV and UKV were measured in two 24-hour urine specimens at baseline (1997-1998) and midway during follow-up (2001-2003). CKD was defined as de novo development of eGFR under 60 ml/min per 1.73 m(2) or albuminuria over 30 mg/24 hours, or both. Baseline UNaV and UKV were 135 mmol/24 hours (interquartile range: 106-169 mmol/24 hours) and 70 mmol/24 hours (interquartile range, 57-85 mmol/24 hours), respectively. During a median follow-up of 10.3 years, 872 patients developed CKD. After multivariable adjustment for important covariables, no association was observed between UNaV and risk of CKD (hazard ratio per 50 mmol/24 hours [1 SD] increment, 0.97; 95% confidence interval, 0.89-1.06). Each 21 mmol/24 hours (1 SD) decrement in UKV was significantly associated with a 16% higher risk of developing CKD (multivariable-adjusted hazard ratio, 1.16; 95% confidence interval, 1.06-1.28). Thus, low UKV, and not high UNaV, was associated with an increased risk of developing CKD in a population-based cohort with normal kidney function.
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Affiliation(s)
- Lyanne M Kieneker
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
| | - Stephan J L Bakker
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Rudolf A de Boer
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Gerjan J Navis
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Ron T Gansevoort
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Michel M Joosten
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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Pilic L, Pedlar CR, Mavrommatis Y. Salt-sensitive hypertension: mechanisms and effects of dietary and other lifestyle factors. Nutr Rev 2016; 74:645-58. [PMID: 27566757 DOI: 10.1093/nutrit/nuw028] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Salt sensitivity, which is an increase in blood pressure in response to high dietary salt intake, is an independent risk factor for cardiovascular disease and mortality. It is associated with physiological, environmental, demographic, and genetic factors. This review focuses on the physiological mechanisms of salt sensitivity in populations at particular risk, along with the associated dietary factors. The interplay of mechanisms such as the renin-angiotensin aldosterone system, endothelial dysfunction, ion transport, and estrogen decrease in women contributes to development of salt sensitivity. Because of their effects on these mechanisms, higher dietary intakes of potassium, calcium, vitamin D, antioxidant vitamins, and proteins rich in L-arginine, as well as adherence to dietary patterns similar to the DASH (Dietary Approaches to Stop Hypertension) diet, can be beneficial to salt-sensitive populations. In contrast, diets similar to the typical Western diet, which is rich in saturated fats, sucrose, and fructose, together with excessive alcohol consumption, may exacerbate salt-sensitive changes in blood pressure. Identifying potential mechanisms of salt sensitivity in susceptible populations and linking them to protective or harmful dietary and lifestyle factors can lead to more specific guidelines for the prevention of hypertension and cardiovascular disease.
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Affiliation(s)
- Leta Pilic
- L. Pilic, C.R. Pedlar, and Y. Mavrommatis are with the School of Sport, Health and Applied Science, St Mary's University, Twickenham, London, United Kingdom. CR Pedlar is with the Cardiovascular Performance Program, Massachusetts General Hospital, Boston, Massachusetts, USA.
| | - Charles R Pedlar
- L. Pilic, C.R. Pedlar, and Y. Mavrommatis are with the School of Sport, Health and Applied Science, St Mary's University, Twickenham, London, United Kingdom. CR Pedlar is with the Cardiovascular Performance Program, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Yiannis Mavrommatis
- L. Pilic, C.R. Pedlar, and Y. Mavrommatis are with the School of Sport, Health and Applied Science, St Mary's University, Twickenham, London, United Kingdom. CR Pedlar is with the Cardiovascular Performance Program, Massachusetts General Hospital, Boston, Massachusetts, USA
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Cárdenas A, Campos J, Ehrenfeld P, Mezzano S, Ruiz-Ortega M, Figueroa CD, Ardiles L. Up-regulation of the kinin B2 receptor pathway modulates the TGF-β/Smad signaling cascade to reduce renal fibrosis induced by albumin. Peptides 2015; 73:7-19. [PMID: 26256678 DOI: 10.1016/j.peptides.2015.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 07/09/2015] [Accepted: 08/04/2015] [Indexed: 12/24/2022]
Abstract
The presence of high protein levels in the glomerular filtrate plays an important role in renal fibrosis, a disorder that justifies the use of animal models of experimental proteinuria. Such models have proved useful as tools in the study of the pathogenesis of chronic, progressive renal disease. Since bradykinin and the kinin B2 receptor (B2R) belong to a renoprotective system with mechanisms still unclarified, we investigated its anti-fibrotic role in the in vivo rat model of overload proteinuria. Upon up-regulating the kinin system by a high potassium diet we observed reduction of tubulointerstitial fibrosis, decreased renal expression of α-smooth muscle actin (α-SMA) and vimentin, reduced Smad3 phosphorylation and increase of Smad7. These cellular and molecular effects were reversed by HOE-140, a specific B2R antagonist. In vitro experiments, performed on a cell line of proximal tubular epithelial cells, showed that high concentrations of albumin induced expression of mesenchymal biomarkers, in concomitance with increases in TGF-β1 mRNA and its functionally active peptide, TGF-β1. Stimulation of the tubule cells by bradykinin inhibited the albumin-induced changes, namely α-SMA and vimentin were reduced, and cytokeratin recovered together with increase in Smad7 levels and decrease in type II TGF-β1 receptor, TGF-β1 mRNA and its active fragment. The protective changes produced by bradykinin in vitro were blocked by HOE-140. The development of stable bradykinin analogues and/or up-regulation of the B2R signaling pathway may prove value in the management of chronic renal fibrosis in progressive proteinuric renal diseases.
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Affiliation(s)
- Areli Cárdenas
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile
| | - Javiera Campos
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile
| | - Pamela Ehrenfeld
- Department of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia, Chile
| | - Sergio Mezzano
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile
| | - Marta Ruiz-Ortega
- IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Carlos D Figueroa
- Department of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia, Chile
| | - Leopoldo Ardiles
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile.
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16
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Kopkan L, Husková Z, Jíchová Š, Červenková L, Červenka L, Saifudeen Z, El-Dahr SS. Conditional knockout of collecting duct bradykinin B2 receptors exacerbates angiotensin II-induced hypertension during high salt intake. Clin Exp Hypertens 2015; 38:1-9. [PMID: 26151827 DOI: 10.3109/10641963.2015.1047945] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We elucidated the role of collecting duct kinin B2 receptor (B2R) in the development of salt-sensitivity and angiotensin II (ANG II)-induced hypertension. To this end, we used a Cre-Lox recombination strategy to generate mice lacking Bdkrb2 gene for B2R in the collecting duct (Hoxb7-Cre(tg/+):Bdkrb2(flox/flox)). In 3 groups of control (Bdkrb2(flox/flox)) and 3 groups of UB(Bdkrb2-/-) mice, systolic blood pressure (SBP) responses to high salt intake (4 or 8% NaCl; HS) were monitored by radiotelemetry in comparison with standard salt diet (0.4% NaCl) prior to and during subcutaneous ANG II infusion (1000 ng/min/kg) via osmotic minipumps. High salt intakes alone for 2 weeks did not alter SBP in either strain. ANG II significantly increased SBP equally in control (121 ± 2 to 156 ± 3 mmHg) and UB(Bdkrb2-/-) mice (120 ± 2 to 153 ± 2 mmHg). The development of ANG II-induced hypertension was exacerbated by 4%HS in both control (125 ± 3 to 164 ± 5 mmHg) and UB(Bdkrb2-/-) mice (124 ± 2 to 162 ± 3 mmHg) during 2 weeks. Interestingly, 8%HS caused a more profound and earlier ANG II-induced hypertension in UB(Bdkrb2-/-) (129 ± 2 to 166 ± 3 mmHg) as compared to control (128 ± 2 to 158 ± 2 mmHg) and it was accompanied by body weight loss and increased mortality. In conclusion, targeted inactivation of B2R in the renal collecting duct does not cause salt-sensitivity; however, collecting duct B2R attenuates the hypertensive actions of ANG II under conditions of very high salt intake.
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Affiliation(s)
- Libor Kopkan
- a Center of Experimental Medicine, Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Zuzana Husková
- a Center of Experimental Medicine, Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Šárka Jíchová
- a Center of Experimental Medicine, Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Lenka Červenková
- a Center of Experimental Medicine, Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Luděk Červenka
- a Center of Experimental Medicine, Institute for Clinical and Experimental Medicine , Prague , Czech Republic .,b Department of Pathophysiology, 2nd Faculty of Medicine , Charles University , Prague , Czech Republic , and
| | - Zubaida Saifudeen
- c Department of Pediatrics , Tulane University School of Medicine , New Orleans , LA , USA
| | - Samir S El-Dahr
- c Department of Pediatrics , Tulane University School of Medicine , New Orleans , LA , USA
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17
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The relationship between estimated sodium and potassium excretion and subsequent renal outcomes. Kidney Int 2014; 86:1205-12. [DOI: 10.1038/ki.2014.214] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 04/10/2014] [Accepted: 05/08/2014] [Indexed: 11/08/2022]
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Low-density lipoprotein apheresis ameliorates monthly estimated glomerular filtration rate declines in patients with renal cholesterol crystal embolism. J Artif Organs 2014; 18:72-8. [DOI: 10.1007/s10047-014-0801-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 10/12/2014] [Indexed: 02/06/2023]
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Pre-stimulation of the kallikrein system in cisplatin-induced acute renal injury: An approach to renoprotection. Toxicol Appl Pharmacol 2014; 280:216-23. [DOI: 10.1016/j.taap.2014.07.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 07/17/2014] [Accepted: 07/30/2014] [Indexed: 12/26/2022]
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20
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Moodley K, Naidoo Y, Mackraj I. Effects of Tulbaghia violacea Harv. (Alliaceae) rhizome methanolic extract on kidney function and morphology in Dahl salt-sensitive rats. JOURNAL OF ETHNOPHARMACOLOGY 2014; 155:1194-1203. [PMID: 25017374 DOI: 10.1016/j.jep.2014.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 06/12/2014] [Accepted: 07/01/2014] [Indexed: 06/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tulbaghia violacea has been used traditionally for the treatment of several ailments, including hypertension. The herb has been shown to have antihypertensive properties which have been attributed to its angiotensin-converting enzymeinhibitory (ACEI) activity. It could, therefore, prove beneficial in ameliorating renal pathology associated with hypertension. To evaluate the effects of long-term administration of Tulbaghia violacea on renal function and morphology in the Dahl salt-sensitive (DSS) rat model. MATERIALS AND METHODS Male DSS rats were treated intra-peritoneally (i.p.) as follows: methanolic extract of Tulbaghia violacea: (TVL) (50 mg/kg/b.w.), captopril: (CAP) (25 mg/kg/b.w.), or distilled water, control: (CON) (3 ml/kg/b.w.). Blood pressure (BP) was measured bi-weekly, whilst 24-h urine volumes and electrolyte concentrations were assessed weekly. Animals were sacrificed on day 49 by halothane overdose. Blood was removed for determination of plasma and serum electrolytes. Left kidney tissues were harvested for the determination of nuclear factor-kappaβ (NF-kβ) and transforming growth factor-β (TGF-β) gene expressions. RESULTS TVL significantly reduced mean arterial pressure (MAP) and diastolic blood pressure (DBP). TVL showed reduced blood urea nitrogen, serum creatinine, total protein in urine as well as increased serum total protein. TVL decreased thiobarbituric acid reactive substances (TBARS) and increased glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity and nitric oxide significantly. NF-kβ and TGF-β) gene expressions were significantly reduced in TVL and CAP treated rats. Moreover, renal morphology improved significantly in TVL and CAP treated animals. CONCLUSION TVL and CAP demonstrated marked improvement in renal function and morphology.
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Affiliation(s)
- Kogi Moodley
- Department of Human Physiology, School of Basic Medical Sciences, Faculty of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Yougasphree Naidoo
- Department of Biology, School of Biological and Conservation Sciences, Faculty of Science and Agriculture, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Irene Mackraj
- Department of Human Physiology, School of Basic Medical Sciences, Faculty of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa.
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Blaes N, Girolami JP. Targeting the 'Janus face' of the B2-bradykinin receptor. Expert Opin Ther Targets 2013; 17:1145-66. [PMID: 23957374 DOI: 10.1517/14728222.2013.827664] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Kinins are main active mediators of the kallikrein-kinin system (KKS) via bradykinin type 1 inducible (B1R) and type 2 constitutive (B2R) receptors. B2R mediates most physiological bradykinin (BK) responses, including vasodilation, natriuresis, NO, prostaglandins release. AREAS COVERED The article summarizes knowledge on kinins, B2R signaling and biological functions; highlights crosstalks between B2R and renin-angiotensin system (RAS). The double role (Janus face) in physiopathology, namely the beneficial protection of the endothelium, which forms the basis for the therapeutical utilization of B2 receptor agonists, on the one side, and the involvement of B2R in inflammation or infection diseases and in pain mechanisms, which justifies the use of B2R antagonists, on the other side, is extensively analyzed. EXPERT OPINION For decades, the B2R has been unconsciously activated during angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) treatments. Whether direct B2R targeting with stable agonists could bring additional therapeutic benefit to RAS inhibition should be investigated. Efficacy, established in experimental models, should be confirmed by translational studies in cardiovascular pathologies, glaucoma, Duchenne cardiopathy and during brain cancer therapy. The other face of B2R is targeted by antagonists already approved to treat hereditary angioedema. The use of antagonists could be extended to other angioedema and efficacy tested against acute pain and inflammatory diseases.
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Affiliation(s)
- Nelly Blaes
- INSERM, U1048, Institute of Metabolic and Cardiovascular Diseases, I2MC, Université Paul Sabatier , F-31432, Toulouse , France
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