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Husková Z, Kikerlová S, Miklovič M, Kala P, Papoušek F, Neckář J. Inappropriate activation of the renin-angiotensin system improves cardiac tolerance to ischemia/reperfusion injury in rats with late angiotensin II-dependent hypertension. Front Physiol 2023; 14:1151308. [PMID: 37389123 PMCID: PMC10301744 DOI: 10.3389/fphys.2023.1151308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 06/05/2023] [Indexed: 07/01/2023] Open
Abstract
The aim of the study was to clarify the role of the interplay between hypertension and the renin-angiotensin system (RAS) in the pathophysiology of myocardial ischemia/reperfusion (I/R) injury. We hypothesized that in the late phase of hypertension with already developed signs of end-organ damage, inappropriate RAS activation could impair cardiac tolerance to I/R injury. Experiments were performed in male Cyp1a1-Ren-2 transgenic rats with inducible hypertension. The early phase of ANG II-dependent hypertension was induced by 5 days and the late phase by the 13 days dietary indole-3-carbinol (I3C) administration. Noninduced rats served as controls. Echocardiography and pressure-volume analysis were performed, angiotensins' levels were measured and cardiac tolerance to ischemia/reperfusion injury was studied. The infarct size was significantly reduced (by 50%) in 13 days I3C-induced hypertensive rats with marked cardiac hypertrophy, this reduction was abolished by losartan treatment. In the late phase of hypertension there are indications of a failing heart, mainly in reduced preload recruitable stroke work (PRSW), but only nonsignificant trends in worsening of some other parameters, showing that the myocardium is in a compensated phase. The influence of the RAS depends on the balance between the vasoconstrictive and the opposed vasodilatory axis. In the initial stage of hypertension, the vasodilatory axis of the RAS prevails, and with the development of hypertension the vasoconstrictive axis of the RAS becomes stronger. We observed a clear effect of AT1 receptor blockade on maximum pressure in left ventricle, cardiac hypertrophy and ANG II levels. In conclusion, we confirmed improved cardiac tolerance to I/R injury in hypertensive hypertrophied rats and showed that, in the late phase of hypertension, the myocardium is in a compensated phase.
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Affiliation(s)
- Zuzana Husková
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Soňa Kikerlová
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Matúš Miklovič
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Department of Pathophysiology, 2nd Faculty of Medicine, Charles University, Prague, Czechia
| | - Petr Kala
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Department of Cardiology, 2nd Medical Faculty, Charles University and University Hospital Motol, Prague, Czechia
| | - František Papoušek
- Laboratory of Developmental Cardiology, Institute of Physiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Jan Neckář
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Laboratory of Developmental Cardiology, Institute of Physiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
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Husková Z, Kikerlová S, Sadowski J, Alánová P, Sedláková L, Papoušek F, Neckář J. Increased Endogenous Activity of the Renin-Angiotensin System Reduces Infarct Size in the Rats with Early Angiotensin II-dependent Hypertension which Survive the Acute Ischemia/Reperfusion Injury. Front Pharmacol 2021; 12:679060. [PMID: 34122103 PMCID: PMC8193500 DOI: 10.3389/fphar.2021.679060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/11/2021] [Indexed: 01/13/2023] Open
Abstract
We investigated the role of the interaction between hypertension and the renin-angiotensin system in the pathophysiology of myocardial ischemia/reperfusion injury. We hypothesized that in the early phase of angiotensin II (ANG II)-dependent hypertension with developed left ventricular hypertrophy, cardioprotective mechanism(s) are fully activated. The experiments were performed in transgenic rats with inducible hypertension, noninduced rats served as controls. The early phase of ANG II-dependent hypertension was induced by five-days (5 days) dietary indole-3-carbinol administration. Cardiac hypertrophy, ANG II and ANG 1-7 levels, protein expression of their receptors and enzymes were determined. Separate groups were subjected to acute myocardial ischemia/reperfusion injury, and infarct size and ventricular arrhythmias were assessed. Induced rats developed marked cardiac hypertrophy accompanied by elevated ANG levels. Ischemia/reperfusion mortality was significantly higher in induced than noninduced rats (52.1 and 25%, respectively). The blockade of AT1 receptors with losartan significantly increased survival rate in both groups. Myocardial infarct size was significantly reduced after 5 days induction (by 11%), without changes after losartan treatment. In conclusion, we confirmed improved cardiac tolerance to ischemia/reperfusion injury in hypertensive cardiohypertrophied rats and found that activation of AT1 receptors by locally produced ANG II in the heart was not the mechanism underlying infarct size reduction.
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Affiliation(s)
- Zuzana Husková
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Soňa Kikerlová
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Janusz Sadowski
- Department of Renal and Body Fluid Physiology, Mossakowski Medical Research Institute, Polish Academy of Science, Warsaw, Poland
| | - Petra Alánová
- Laboratory of Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Lenka Sedláková
- Laboratory of Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - František Papoušek
- Laboratory of Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Jan Neckář
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czechia.,Laboratory of Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
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Dang Z, Su S, Jin G, Nan X, Ma L, Li Z, Lu D, Ge R. Tsantan Sumtang attenuated chronic hypoxia-induced right ventricular structure remodeling and fibrosis by equilibrating local ACE-AngII-AT1R/ACE2-Ang1-7-Mas axis in rat. JOURNAL OF ETHNOPHARMACOLOGY 2020; 250:112470. [PMID: 31862407 DOI: 10.1016/j.jep.2019.112470] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 12/02/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tsantan Sumtang, which consists of Choerospondias axillaris (Roxb.) Burtt et Hill, Myristica fragrans Houtt and Santalum album L, is a traditional and common prescription of Tibetan medicine. Tsantan Sumtang originates from Four Tantra with properties of nourishing heart and has been used as a folk medicine for cardiovascular diseases and heart failure in Qinghai, Tibet and Inner Mongolia. Our previous studies found that Tsantan Sumtang showed beneficial effects on right ventricular structure in hypoxia rats, while the underling mechanism remains unclear. AIM OF THE STUDY To elucidate the underlying mechanisms of Tsantan Sumtang attenuated right ventricular (RV) remodeling and fibrosis of chronic hypoxia-induced pulmonary arterial hypertension (HPAH) rats. MATERIALS AND METHODS Fifty male Sprague Dawley (SD) rats (170 ± 20 g) were randomly divided into control group, hypoxia group, and hypoxia + Tsantan Sumtang groups (1.0 g· kg-1·day-1, 1.25 g· kg-1·day-1, 1.5 g ·kg-1·day-1). Rats in the hypoxia group and hypoxia + Tsantan Sumtang groups were maintained in a hypobaric chamber by adjusting the inner pressure and oxygen content to simulate an altitude of 4500 m for 28 days. The mean pulmonary arterial pressure (mPAP), right ventricle hypertrophy index (RVHI), the ratio of RV weight to tibia length (TL) (RV/TL), heart rate (HR) and RV systolic pressure (RVSP) was determined. Histomorphological assay of RV structure was evaluated by hematoxylin and eosin (HE) staining. RV tissue fibrosis was assessed by collagen proportion area (CPA), collagen I, collagen III and hydroxyproline content. CPA was obtained by picro-sirius red staining (PSR). The expression of collagen I and collagen III were detected by immunohistochemistry and western blotting. The hydroxyproline content was detected by alkaline hydrolysis. In addition, the level of angiotensin II (AngII) and angiotensin 1-7 (Ang1-7) in RV tissue was tested by enzyme-linked immune sorbent assay (ELISA). Protein expression of angiotensin-converting enzyme (ACE), AngII, AngII type 1 receptor (AT1R), angiotensin-converting enzyme 2 (ACE2), Mas receptor (Mas) were determined by immunohistochemistry and western blotting. mRNA level of ACE, AT1R, ACE2, Mas were tested by qPCR. The chemical profile of Tsantan Sumtang was revealed by UHPLC-Q-Exactive hybrid quadrupole-orbitrap mass analysis. RESULTS Our results showed that RVHI, RV/TL and RVSP were significantly increased in HPAH rat. Furthermore, levels of collagen I, collagen III and hydroxyproline were up-regulated in RV tissue under hypoxia. We found that RV hypertrophy and fibrosis were associated with increased expression of ACE, AngII, AT1R as well as decreased expression of ACE2, Ang1-7 and Mas. RV remodeling and fibrosis were attenuated after Tsantan Sumtang administration by up-regulating ACE2 and Mas level as well as down-regulating ACE, AngII and AT1R levels in RV tissue. 35 constituents in Tsantan Sumtang were identified. CONCLUSION Tsantan Sumtang attenuated RV remodeling and fibrosis in rat exposed to chronic hypoxia. The pharmacological effect of Tsantan Sumtang was based on equilibrating ACE-AngII-AT1R and ACE2-Ang1-7-Mas axis of RV tissue in HPAH rat.
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Affiliation(s)
- Zhancui Dang
- Research Center for High Altitude Medicine, Qinghai University, Xining, 810001, China; Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Xining, 810001, China; Medical College, Qinghai University, Xining, 810001, China
| | - Shanshan Su
- Technical Center of Xining Customs District, Key Laboratory of Food Safety Research in Qinghai Province, Xining, 810003, China
| | - Guoen Jin
- Research Center for High Altitude Medicine, Qinghai University, Xining, 810001, China; Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Xining, 810001, China
| | - Xingmei Nan
- Medical College, Qinghai University, Xining, 810001, China
| | - Lan Ma
- Research Center for High Altitude Medicine, Qinghai University, Xining, 810001, China; Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Xining, 810001, China
| | - Zhanqiang Li
- Research Center for High Altitude Medicine, Qinghai University, Xining, 810001, China; Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Xining, 810001, China.
| | - Dianxiang Lu
- Research Center for High Altitude Medicine, Qinghai University, Xining, 810001, China; Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Xining, 810001, China.
| | - Rili Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining, 810001, China; Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Xining, 810001, China.
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Zicha J, Hojná S, Kopkan L, Červenka L, Vaněčková I. The absence of sympathoexcitation during the development of hypertension in Cyp1a1 Ren-2 transgenic rats. Physiol Res 2019; 68:329-334. [PMID: 31037948 DOI: 10.33549/physiolres.934151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The insertion of mouse renin gene (Ren-2) into the genome of normotensive rats causes a spontaneous rise of blood pressure (BP), leading to an angiotensin II (Ang II)-dependent form of hypertension in transgenic (mRen-2)27 rats (TGR). However, enhanced sympathetic BP component was demonstrated in heterozygous TGR aged 20 weeks. In the present study we used another model, i.e. Cyp1a1-Ren-2 transgenic rats (iTGR) in which hypertension can be induced by natural xenobiotic indole-3 carbinol (I3C) added to the diet. We investigated whether the development of high blood pressure (BP) in 5-month-old iTGR animals fed I3C diet for 10 days is solely due to enhanced Ang II-dependent vasoconstriction or whether enhanced sympathetic vasoconstriction also participates in BP maintenance in this form of hypertension. Using acute sequential blockade of renin-angiotensin system (RAS), sympathetic nervous system (SNS) and NO synthase (NOS) we have demonstrated that the observed gradual increase of BP in iTGR fed I3C diet was entirely due to the augmentation of Ang II-dependent BP component without significant changes of sympathetic BP component. Thus, the hypertension in iTGR resembles to that of homozygous TGR in which high BP was entirely dependent on Ang II-dependent vasoconstriction. Moreover, our measurements of acute BP response to Rho kinase inhibitor fasudil in animals subjected to a combined blockade of RAS, SNS and NOS indicated the attenuation of basal calcium sensitization in both iTGR and homozygous TGR.
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Affiliation(s)
- J Zicha
- Institute of Physiology CAS, Vídeňská 1083, 142 20 Prague 4, Czech Republic.
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20-Hydroxyeicosatetraenoic acid antagonist attenuates the development of malignant hypertension and reverses it once established: a study in Cyp1a1-Ren-2 transgenic rats. Biosci Rep 2018; 38:BSR20171496. [PMID: 30054426 PMCID: PMC6131326 DOI: 10.1042/bsr20171496] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 07/09/2018] [Accepted: 07/19/2018] [Indexed: 01/13/2023] Open
Abstract
We hypothesized that vascular actions of 20-hydroxyeicosatetraenoic acid (20-HETE), the product of cytochrome P450 (CYP450)-dependent ω-hydroxylase, potentiate prohypertensive actions of angiotensin II (ANG II) in Cyp1a1-Ren-2 transgenic rats, a model of ANG II-dependent malignant hypertension. Therefore, we evaluated the antihypertensive effectiveness of 20-HETE receptor antagonist (AAA) in this model. Malignant hypertension was induced in Cyp1a1-Ren-2 transgenic rats by activation of the renin gene using indole-3-carbinol (I3C), a natural xenobiotic. Treatment with AAA was started either simultaneously with induction of hypertension or 10 days later, during established hypertension. Systolic blood pressure (SBP) was monitored by radiotelemetry, indices of renal and cardiac injury, and kidney ANG II levels were determined. In I3C-induced hypertensive rats, early AAA treatment reduced SBP elevation (to 161 ± 3 compared with 199 ± 3 mmHg in untreated I3C-induced rats), reduced albuminuria, glomerulosclerosis index, and cardiac hypertrophy (P<0.05 in all cases). Untreated I3C-induced rats showed augmented kidney ANG II (405 ± 14 compared with 52 ± 3 fmol/g in non-induced rats, P<0.05) which was markedly lowered by AAA treatment (72 ± 6 fmol/g). Remarkably, in TGR with established hypertension, AAA also decreased SBP (from 187 ± 4 to 158 ± 4 mmHg, P<0.05) and exhibited organoprotective effects in addition to marked suppression of kidney ANG II levels. In conclusion, 20-HETE antagonist attenuated the development and largely reversed the established ANG II-dependent malignant hypertension, likely via suppression of intrarenal ANG II levels. This suggests that intrarenal ANG II activation by 20-HETE is important in the pathophysiology of this hypertension form.
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Tu H, Zhang D, Li YL. Cellular and Molecular Mechanisms Underlying Arterial Baroreceptor Remodeling in Cardiovascular Diseases and Diabetes. Neurosci Bull 2018; 35:98-112. [PMID: 30146675 DOI: 10.1007/s12264-018-0274-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/31/2018] [Indexed: 01/23/2023] Open
Abstract
Clinical trials and animal experimental studies have demonstrated an association of arterial baroreflex impairment with the prognosis and mortality of cardiovascular diseases and diabetes. As a primary part of the arterial baroreflex arc, the pressure sensitivity of arterial baroreceptors is blunted and involved in arterial baroreflex dysfunction in cardiovascular diseases and diabetes. Changes in the arterial vascular walls, mechanosensitive ion channels, and voltage-gated ion channels contribute to the attenuation of arterial baroreceptor sensitivity. Some endogenous substances (such as angiotensin II and superoxide anion) can modulate these morphological and functional alterations through intracellular signaling pathways in impaired arterial baroreceptors. Arterial baroreceptors can be considered as a potential therapeutic target to improve the prognosis of patients with cardiovascular diseases and diabetes.
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Affiliation(s)
- Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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Epoxyeicosatrienoic acid analog attenuates the development of malignant hypertension, but does not reverse it once established: a study in Cyp1a1-Ren-2 transgenic rats. J Hypertens 2017; 34:2008-25. [PMID: 27428043 DOI: 10.1097/hjh.0000000000001029] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE We evaluated the therapeutic effectiveness of a new, orally active epoxyeicosatrienoic acid analog (EET-A) in rats with angiotensin II (ANG II)-dependent malignant hypertension. METHODS Malignant hypertension was induced in Cyp1a1-Ren-2 transgenic rats by activation of the renin gene using indole-3-carbinol (I3C), a natural xenobiotic. EET-A treatment was started either simultaneously with I3C induction process (early treatment) or 10 days later during established hypertension (late treatment). Blood pressure (BP) (radiotelemetry), indices of renal and cardiac injury, and plasma and kidney levels of the components of the renin-angiotensin system (RAS) were determined. RESULTS In I3C-induced hypertensive rats, early EET-A treatment attenuated BP increase (to 175 ± 3 versus 193 ± 4 mmHg, P < 0.05, on day 13), reduced albuminuria (15 ± 1 versus 28 ± 2 mg/24 h, P < 0.05), and cardiac hypertrophy as compared with untreated I3C-induced rats. This was associated with suppression of plasma and kidney ANG II levels (48 ± 6 versus 106 ± 9 and 122 ± 19 versus 346 ± 11 fmol ml or g, respectively, P < 0.05) and increases in plasma and kidney angiotensin (1-7) concentrations (84 ± 9 versus 37 ± 6 and 199 ± 12 versus 68 ± 9 fmol/ml or g, respectively, P < 0.05). Remarkably, late EET-A treatment did not lower BP or improve renal and cardiac injury; indices of RAS activity were not affected. CONCLUSION The new, orally active EET-A attenuated the development of experimental ANG II-dependent malignant hypertension, likely via suppression of the hypertensiogenic axis and augmentation of the vasodilatory/natriuretic axis of RAS.
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Jíchová Š, Doleželová Š, Kopkan L, Kompanowska-Jezierska E, Sadowski J, Červenka L. Fenofibrate Attenuates Malignant Hypertension by Suppression of the Renin-angiotensin System: A Study in Cyp1a1-Ren-2 Transgenic Rats. Am J Med Sci 2016; 352:618-630. [DOI: 10.1016/j.amjms.2016.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/17/2016] [Accepted: 09/21/2016] [Indexed: 11/29/2022]
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Husková Z, Kopkan L, Červenková L, Doleželová Š, Vaňourková Z, Škaroupková P, Nishiyama A, Kompanowska-Jezierska E, Sadowski J, Kramer HJ, Červenka L. Intrarenal alterations of the angiotensin-converting enzyme type 2/angiotensin 1-7 complex of the renin-angiotensin system do not alter the course of malignant hypertension in Cyp1a1-Ren-2 transgenic rats. Clin Exp Pharmacol Physiol 2016; 43:438-49. [DOI: 10.1111/1440-1681.12553] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/15/2016] [Accepted: 01/26/2016] [Indexed: 01/13/2023]
Affiliation(s)
- Zuzana Husková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Libor Kopkan
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Lenka Červenková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Šárka Doleželová
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Zdeňka Vaňourková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Petra Škaroupková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | | | - Elzbieta Kompanowska-Jezierska
- Department of Renal and Body Fluid Physiology; Mossakowski Medical Research Centre; Polish Academy of Science; Warsaw Poland
| | - Janusz Sadowski
- Department of Renal and Body Fluid Physiology; Mossakowski Medical Research Centre; Polish Academy of Science; Warsaw Poland
| | - Herbert J. Kramer
- Section of Nephrology; Department of Medicine; University of Bonn; Bonn Germany
| | - Luděk Červenka
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
- Department of Pathophysiology; 2nd Faculty of Medicine; Charles University; Prague Czech Republic
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Sporková A, Jíchová S, Husková Z, Kopkan L, Nishiyama A, Hwang SH, Hammock BD, Imig JD, Kompanowska-Jezierska E, Sadowski J, Kramer HJ, Cervenka L. Different mechanisms of acute versus long-term antihypertensive effects of soluble epoxide hydrolase inhibition: studies in Cyp1a1-Ren-2 transgenic rats. Clin Exp Pharmacol Physiol 2015; 41:1003-13. [PMID: 25224811 DOI: 10.1111/1440-1681.12310] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 08/26/2014] [Accepted: 08/29/2014] [Indexed: 01/13/2023]
Abstract
Recent studies have shown that the long-term antihypertensive action of soluble epoxide hydrolase inhibition (sEH) in angiotensin-II (AngII)-dependent hypertension might be mediated by the suppression of intrarenal AngII levels. To test this hypothesis, we examined the effects of acute (2 days) and chronic (14 days) sEH inhibition on blood pressure (BP) in transgenic rats with inducible AngII-dependent hypertension. AngII-dependent malignant hypertension was induced by 10 days' dietary administration of indole-3-carbinol (I3C), a natural xenobiotic that activates the mouse renin gene in Cyp1a1-Ren-2 transgenic rats. BP was monitored by radiotelemetry. Acute and chronic sEH inhibition was achieved using cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy) benzoic acid, given at doses of 0.3, 3, 13, 26, 60 and 130 mg/L in drinking water. At the end of experiments, renal concentrations of epoxyeicosatrienoic acids, their inactive metabolites dihydroxyeicosatrienoic acids and AngII were measured. Acute BP-lowering effects of sEH inhibition in I3C-induced rats was associated with a marked increase in renal epoxyeicosatrienoic acids to dihydroxyeicosatrienoic acids ratio and acute natriuresis. Chronic treatment with cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy) benzoic acid in I3C-induced rats elicited dose-dependent persistent BP lowering associated with a significant reduction of plasma and kidney AngII levels. Our findings show that the acute BP-lowering effect of sEH inhibition in I3C-induced Cyp1a1-Ren-2 transgenic rats is mediated by a substantial increase in intrarenal epoxyeicosatrienoic acids and their natriuretic action without altering intrarenal renin-angiotensin system activity. Long-term antihypertensive action of cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy) benzoic acid in I3C-induced Cyp1a1-Ren-2 transgenic rats is mediated mostly by suppression of intrarenal AngII concentration.
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Affiliation(s)
- Alexandra Sporková
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
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Červenka L, Melenovský V, Husková Z, Škaroupková P, Nishiyama A, Sadowski J. Inhibition of soluble epoxide hydrolase counteracts the development of renal dysfunction and progression of congestive heart failure in Ren-2 transgenic hypertensive rats with aorto-caval fistula. Clin Exp Pharmacol Physiol 2015; 42:795-807. [DOI: 10.1111/1440-1681.12419] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/27/2015] [Accepted: 05/01/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Luděk Červenka
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
- Department of Pathophysiology; 2nd Faculty of Medicine; Charles University; Prague Czech Republic
| | - Vojtěch Melenovský
- Department of Cardiology; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Zuzana Husková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | - Petra Škaroupková
- Centre for Experimental Medicine; Institute for Clinical and Experimental Medicine; Prague Czech Republic
| | | | - Janusz Sadowski
- Department of Renal and Body Fluid Physiology; M. Mossakowski Medical Research Centre; Polish Academy of Science; Warsaw Poland
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Červenka L, Melenovský V, Husková Z, Sporková A, Bürgelová M, Škaroupková P, Hwang SH, Hammock BD, Imig JD, Sadowski J. Inhibition of soluble epoxide hydrolase does not improve the course of congestive heart failure and the development of renal dysfunction in rats with volume overload induced by aorto-caval fistula. Physiol Res 2015; 64:857-73. [PMID: 26047375 DOI: 10.33549/physiolres.932977] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The detailed mechanisms determining the course of congestive heart failure (CHF) and associated renal dysfunction remain unclear. In a volume overload model of CHF induced by creation of aorto-caval fistula (ACF) in Hannover Sprague-Dawley (HanSD) rats we explored the putative pathogenetic contribution of epoxyeicosatrienoic acids (EETs), active products of CYP-450 dependent epoxygenase pathway of arachidonic acid metabolism, and compared it with the role of the renin-angiotensin system (RAS). Chronic treatment with cis-4-[4-(3-adamantan-1-yl-ureido) cyclohexyloxy]benzoic acid (c-AUCB, 3 mg/l in drinking water), an inhibitor of soluble epoxide hydrolase (sEH) which normally degrades EETs, increased intrarenal and myocardial EETs to levels observed in sham-operated HanSD rats, but did not improve the survival or renal function impairment. In contrast, chronic angiotensin-converting enzyme inhibition (ACEi, trandolapril, 6 mg/l in drinking water) increased renal blood flow, fractional sodium excretion and markedly improved survival, without affecting left ventricular structure and performance. Hence, renal dysfunction rather than cardiac remodeling determines long-term mortality in advanced stage of CHF due to volume overload. Strong protective actions of ACEi were associated with suppression of the vasoconstrictor/sodium retaining axis and activation of vasodilatory/natriuretic axis of the renin-angiotensin system in the circulating blood and kidney tissue.
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Affiliation(s)
- L Červenka
- Department of Pathophysiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic.
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Majid DSA, Prieto MC, Navar LG. Salt-Sensitive Hypertension: Perspectives on Intrarenal Mechanisms. Curr Hypertens Rev 2015; 11:38-48. [PMID: 26028244 DOI: 10.2174/1573402111666150530203858] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 04/22/2015] [Accepted: 04/24/2015] [Indexed: 12/12/2022]
Abstract
Salt sensitive hypertension is characterized by increases in blood pressure in response to increases in dietary salt intake and is associated with an enhanced risk of cardiovascular and renal morbidity. Although researchers have sought for decades to understand how salt sensitivity develops in humans, the mechanisms responsible for the increases in blood pressure in response to high salt intake are complex and only partially understood. Until now, scientists have been unable to explain why some individuals are salt sensitive and others are salt resistant. Although a central role for the kidneys in the development of salt sensitivity and hypertension has been generally accepted, it is also recognized that hypertension is of multifactorial origin and a variety of factors can induce, or prevent, blood pressure responsiveness to the manipulation of salt intake. Excess salt intake in susceptible persons may also induce inappropriate central and sympathetic nervous system responses and increase the production of intrarenal angiotensin II, catecholamines and other factors such as oxidative stress and inflammatory cytokines. One key factor is the concomitant inappropriate or paradoxical activation of the intrarenal renin-angiotensin system, by high salt intake. This is reflected by the increases in urinary angiotensinogen during high salt intake in salt sensitive models. A complex interaction between neuroendocrine factors and the kidney may underlie the propensity for some individuals to retain salt and develop salt-dependent hypertension. In this review, we focus mainly on the renal contributions that provide the mechanistic links between chronic salt intake and the development of hypertension.
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Affiliation(s)
- Dewan S A Majid
- Department of Physiology, SL39, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
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HAMPL V, HERGET J, BÍBOVÁ J, BAŇASOVÁ A, HUSKOVÁ Z, VAŇOURKOVÁ Z, JÍCHOVÁ Š, KUJAL P, VERNEROVÁ Z, SADOWSKI J, ČERVENKA L. Intrapulmonary Activation of the Angiotensin-Converting Enzyme Type 2/Angiotensin 1-7/G-Protein-Coupled Mas Receptor Axis Attenuates Pulmonary Hypertension in Ren-2 Transgenic Rats Exposed to Chronic Hypoxia. Physiol Res 2015; 64:25-38. [DOI: 10.33549/physiolres.932861] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The present study was performed to evaluate the role of intrapulmonary activity of the two axes of the renin-angiotensin system (RAS): vasoconstrictor angiotensin-converting enzyme (ACE)/angiotensin II (ANG II)/ANG II type 1 receptor (AT1) axis, and vasodilator ACE type 2 (ACE2)/angiotensin 1-7 (ANG 1-7)/Mas receptor axis, in the development of hypoxic pulmonary hypertension in Ren-2 transgenic rats (TGR). Transgene-negative Hannover Sprague-Dawley (HanSD) rats served as controls. Both TGR and HanSD rats responded to two weeks´ exposure to hypoxia with a significant increase in mean pulmonary arterial pressure (MPAP), however, the increase was much less pronounced in the former. The attenuation of hypoxic pulmonary hypertension in TGR as compared to HanSD rats was associated with inhibition of ACE gene expression and activity, inhibition of AT1 receptor gene expression and suppression of ANG II levels in lung tissue. Simultaneously, there was an increase in lung ACE2 gene expression and activity and, in particular, ANG 1-7 concentrations and Mas receptor gene expression. We propose that a combination of suppression of ACE/ANG II/AT1 receptor axis and activation of ACE2/ANG 1-7/Mas receptor axis of the RAS in the lung tissue is the main mechanism explaining attenuation of hypoxic pulmonary hypertension in TGR as compared with HanSD rats.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - L. ČERVENKA
- Department of Pathophysiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
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Kujal P, Čertíková Chábová V, Škaroupková P, Husková Z, Vernerová Z, Kramer HJ, Walkowska A, Kompanowska-Jezierska E, Sadowski J, Kitada K, Nishiyama A, Hwang SH, Hammock BD, Imig JD, Červenka L. Inhibition of soluble epoxide hydrolase is renoprotective in 5/6 nephrectomized Ren-2 transgenic hypertensive rats. Clin Exp Pharmacol Physiol 2014; 41:227-37. [PMID: 24471737 PMCID: PMC4038339 DOI: 10.1111/1440-1681.12204] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 11/18/2013] [Accepted: 12/20/2013] [Indexed: 01/13/2023]
Abstract
1. The aim of the present study was to test the hypothesis that increasing kidney tissue concentrations of epoxyeicosatrienoic acids (EETs) by preventing their degradation to the biologically inactive dihydroxyeicosatrienoic acids (DHETEs) using blockade of soluble epoxide hydrolase (sEH) would attenuate the progression of chronic kidney disease (CKD). 2. Ren-2 transgenic rats (TGR) after 5/6 renal mass reduction (5/6 NX) served as a model of CKD associated with angiotensin (Ang) II-dependent hypertension. Soluble epoxide hydrolase was inhibited using cis-4-[4-(3-adamantan-1-yl-ureido)cyclohexyloxy]benzoic acid (c-AUCB; 3 mg/L drinking water) for 20 weeks after 5/6 NX. Sham-operated normotensive transgene-negative Hannover Sprague-Dawley (HanSD) rats served as controls. 3. When applied in TGR subjected to 5/6 NX, c-AUCB treatment improved survival rate, prevented the increase in blood pressure, retarded the progression of cardiac hypertrophy, reduced proteinuria and the degree of glomerular and tubulointerstitial injury and reduced glomerular volume. All these organ-protective actions were associated with normalization of the intrarenal EETs : DHETEs ratio, an index of the availability of biologically active EETs, to levels observed in sham-operated HanSD rats. There were no significant concurrent changes of increased intrarenal AngII content. 4. Together, these results show that 5/6 NX TGR exhibit a profound deficiency of intrarenal availability of active epoxygenase metabolites (EETs), which probably contributes to the progression of CKD in this model of AngII-dependent hypertension, and that restoration of intrarenal availability of EETs using long-term c-AUCB treatment exhibits substantial renoprotective actions.
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Affiliation(s)
- Petr Kujal
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Charles University, Prague, Czech Republic; Department of Pathology, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
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Červenka L, Bíbová J, Husková Z, Vaňourková Z, Kramer HJ, Herget J, Jíchová Š, Sadowski J, Hampl V. Combined suppression of the intrarenal and circulating vasoconstrictor renin-ACE-ANG II axis and augmentation of the vasodilator ACE2-ANG 1-7-Mas axis attenuates the systemic hypertension in Ren-2 transgenic rats exposed to chronic hypoxia. Physiol Res 2014; 64:11-24. [PMID: 25194129 DOI: 10.33549/physiolres.932842] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The aim of the present study was to test the hypothesis that chronic hypoxia would aggravate hypertension in Ren-2 transgenic rats (TGR), a well-defined monogenetic model of hypertension with increased activity of endogenous renin-angiotensin system (RAS). Systolic blood pressure (SBP) in conscious rats and mean arterial pressure (MAP) in anesthetized TGR and normotensive Hannover Sprague-Dawley (HanSD) rats were determined under normoxia that was either continuous or interrupted by two weeks´ hypoxia. Expression, activities and concentrations of individual components of RAS were studied in plasma and kidney of TGR and HanSD rats under normoxic conditions and after exposure to chronic hypoxia. In HanSD rats two weeks´ exposure to chronic hypoxia did not alter SBP and MAP. Surprisingly, in TGR it decreased markedly SBP and MAP; this was associated with substantial reduction in plasma and kidney renin activities and also of angiotensin II (ANG II) levels, without altering angiotensin-converting enzyme (ACE) activities. Simultaneously, in TGR the exposure to hypoxia increased kidney ACE type 2 (ACE2) activity and angiotensin 1-7 (ANG 1-7) concentrations as compared with TGR under continuous normoxia. Based on these results, we propose that suppression of the hypertensiogenic ACE-ANG II axis in the circulation and kidney tissue, combined with augmentation of the intrarenal vasodilator ACE2-ANG 1-7 axis, is the main mechanism responsible for the blood pressure-lowering effects of chronic hypoxia in TGR.
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Affiliation(s)
- L Červenka
- Department of Pathophysiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic.
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Čertíková Chábová V, Vernerová Z, Kujal P, Husková Z, Škaroupková P, Tesař V, Kramer HJ, Kompanowska-Jezierska E, Walkowska A, Sadowski J, Červenka L, Vaněčková I. Addition of ET(A) receptor blockade increases renoprotection provided by renin-angiotensin system blockade in 5/6 nephrectomized Ren-2 transgenic rats. Life Sci 2013; 118:297-305. [PMID: 24373834 DOI: 10.1016/j.lfs.2013.12.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/22/2013] [Accepted: 12/13/2013] [Indexed: 01/13/2023]
Abstract
AIMS There is evidence that in addition to hypertension and hyperactivity of the renin-angiotensin system (RAS), enhanced intrarenal activity of endothelin (ET) system contributes to the pathophysiology and progression of chronic kidney disease (CKD). This prompted us to examine if this progression would be alleviated by addition of type A ET receptor (ETA) blockade to the standard blockade of RAS. MAIN METHODS Ren-2 transgenic rats (TGR) after 5/6 renal ablation (5/6 NX) served as a model of CKD. For RAS inhibition a combination of angiotensin-converting enzyme inhibitor (trandolapril, 6 mg/L drinking water) and angiotensin II type 1 receptor blocker (losartan, 100 mg/L drinking water) was used. Alternatively, ETA receptor blocker (atrasentan, 5 mg·kg(-1)·day(-1) in drinking water) was added to the combined RAS blockade. The follow-up period was 44 weeks after 5/6 NX, and the rats' survival rate, systolic blood pressure (SBP), proteinuria and indices of renal glomerular damage were evaluated. KEY FINDINGS The survival rate was at first improved, by either therapeutic regime, however, the efficiency of RAS blockade alone considerably decreased 36 weeks after 5/6 NX: final survival rate of 65% was significantly lower than 91% achieved with combined RAS and ETA receptor blockade. SBP was not affected by the addition of ETA blockade while proteinuria and renal glomerular damage were further reduced. SIGNIFICANCE Our data show that a combined RAS and ETA receptor blockade exhibits additional beneficial effects on survival rate and the progression of CKD in 5/6 NX TGR, as compared with RAS inhibition alone.
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Affiliation(s)
- Věra Čertíková Chábová
- Department of Nephrology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Zdenka Vernerová
- Department of Pathology, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Petr Kujal
- Department of Pathology, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Zuzana Husková
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Petra Škaroupková
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Vladimír Tesař
- Department of Nephrology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Herbert J Kramer
- Section of Nephrology, Medical Policlinic, Department of Medicine, University of Bonn, Bonn, Germany
| | - Elzbieta Kompanowska-Jezierska
- Department of Renal and Body Fluid Physiology, M. Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland
| | - Agnieszka Walkowska
- Department of Renal and Body Fluid Physiology, M. Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland
| | - Janusz Sadowski
- Department of Renal and Body Fluid Physiology, M. Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland
| | - Luděk Červenka
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Ivana Vaněčková
- Institute of Physiology v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Antihypertensive and renoprotective actions of soluble epoxide hydrolase inhibition in ANG II-dependent malignant hypertension are abolished by pretreatment with L-NAME. J Hypertens 2013; 31:321-32. [PMID: 23307303 DOI: 10.1097/hjh.0b013e32835b50aa] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE The present study was performed to investigate in a model of malignant hypertension if the antihypertensive actions of soluble epoxide hydrolase (sEH) inhibition are nitric oxide (NO)-dependent. METHODS ANG II-dependent malignant hypertension was induced through dietary administration for 3 days of the natural xenobiotic indole-3-carbinol (I3C) in Cyp1a1-Ren-2 transgenic rats. Blood pressure (BP) was monitored by radiotelemetry and treatment with the sEH inhibitor [cis-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyl-oxy]-benzoic acid (c-AUCB)] was started 48 h before administration of the diet containing I3C. In separate groups of rats, combined administration of the sEH inhibitor and the nonspecific NO synthase inhibitor [Nω-nitro-L-arginine methyl ester (L-NAME)] on the course of BP in I3C-induced and noninduced rats were evaluated. In addition, combined blockade of renin-angiotensin system (RAS) was superimposed on L-NAME administration in separate groups of rats. After 3 days of experimental protocols, the rats were prepared for renal functional studies and renal concentrations of epoxyeicosatrienoic acids (EETs) and their inactive metabolites dihydroxyeicosatrienoic acids (DHETEs) were measured. RESULTS Treatment with c-AUCB increased the renal EETs/DHETEs ratio, attenuated the increases in BP, and prevented the decreases in renal function and the development of renal damage in I3C-induced Cyp1a1-Ren-2 rats. The BP lowering and renoprotective actions of the treatment with the sEH inhibitor c-AUCB were completely abolished by concomitant administration of L-NAME and not fully rescued by double RAS blockade without altering the increased EETs/DHETEs ratio. CONCLUSION Our current findings indicate that the antihypertensive actions of sEH inhibition in this ANG II-dependent malignant form of hypertension are dependent on the interactions of endogenous bioavailability of EETs and NO.
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Heijnen BFJ, Nelissen J, van Essen H, Fazzi GE, Cohen Tervaert JW, Peutz-Kootstra CJ, Mullins JJ, Schalkwijk CG, Janssen BJA, Struijker-Boudier HAJ. Irreversible renal damage after transient renin-angiotensin system stimulation: involvement of an AT1-receptor mediated immune response. PLoS One 2013; 8:e57815. [PMID: 23469072 PMCID: PMC3585138 DOI: 10.1371/journal.pone.0057815] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 01/26/2013] [Indexed: 01/10/2023] Open
Abstract
Transient activation of the renin-angiotensin system (RAS) induces irreversible renal damage causing sustained elevation in blood pressure (BP) in Cyp1a1-Ren2 transgenic rats. In our current study we hypothesized that activation of the AT1-receptor (AT1R) leads to a T-cell response causing irreversible impairment of renal function and hypertension. Cyp1a1-Ren2 rats harbor a construct for activation of the RAS by indole-3-carbinol (I3C). Rats were fed a I3C diet between 4–8 weeks of age to induce hypertension. Next, I3C was withdrawn and rats were followed-up for another 12 weeks. Additional groups received losartan (20 mg/kg/day) or hydralazine (100 mg/kg/day) treatment between 4–8 weeks. Rats were placed for 24h in metabolic cages before determining BP at week 8, 12 and 20. At these ages, subsets of animals were sacrificed and the presence of kidney T-cell subpopulations was investigated by immunohistochemistry and molecular marker analysis. The development of sustained hypertension was completely prevented by losartan, whereas hydralazine only caused a partial decrease in BP. Markers of renal damage: KIM-1 and osteopontin were highly expressed in urine and kidney samples of I3C-treated rats, even until 20 weeks of age. Additionally, renal expression of regulatory-T cells (Tregs) was highly increased in I3C-treated rats, whereas the expression of T-helper 1 (Th1) cells demonstrated a strong decrease. Losartan prevented these effects completely, whereas hydralazine was unable to affect these changes. In young Cyp1a1-Ren2 rats AT1R activation leads to induction of an immune response, causing a shift from Th1-cells to Tregs, contributing to the development of irreversible renal damage and hypertension.
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Affiliation(s)
- Bart F J Heijnen
- Department of Pharmacology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
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Rands VF, Seth DM, Kobori H, Prieto MC. Sexual dimorphism in urinary angiotensinogen excretion during chronic angiotensin II-salt hypertension. ACTA ACUST UNITED AC 2012; 9:207-18. [PMID: 22795463 DOI: 10.1016/j.genm.2012.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 05/11/2012] [Accepted: 06/14/2012] [Indexed: 01/11/2023]
Abstract
BACKGROUND The intrarenal renin-angiotensin system contributes to hypertension by regulating sodium and water reabsorption throughout the nephron. Sex differences in the intrarenal components of the renin-angiotensin system have been involved in the greater incidence of high blood pressure and progression to kidney damage in males than females. OBJECTIVE This study investigated whether there is a sex difference in the intrarenal gene expression and urinary excretion of angiotensinogen (AGT) during angiotensin II (Ang II)-dependent hypertension and high-salt (HS) diet. METHODS Male and female Sprague-Dawley rats were divided into 5 groups for each sex: Normal-salt control, HS diet (8% NaCl), Ang II-infused (80 ng/min), Ang II-infused plus HS diet, and Ang II-infused plus HS diet and treatment with the Ang II receptor blocker, candesartan (25 mg/L in the drinking water). Rats were evaluated for systolic blood pressure (SBP), kidney AGT mRNA expression, urinary AGT excretion, and proteinuria at different time points during a 14-day protocol. RESULTS Both male and female rats exhibited similar increases in urinary AGT, with increases in SBP during chronic Ang II infusion. HS diet greatly exacerbated the urinary AGT excretion in Ang II-infused rats; males had a 9-fold increase over Ang II alone and females had a 2.5-fold increase. Male rats displayed salt-sensitive SBP increases during Ang II infusion and HS diet, and female rats did not. In the kidney cortex, males displayed greater AGT gene expression than females during all treatments. During Ang II infusion, both sexes exhibited increases in AGT gene message compared with same-sex controls. In addition, HS diet combined with Ang II infusion exacerbated the proteinuria in both sexes. Concomitant Ang II receptor blocker treatment during Ang II infusion and HS diet decreased SBP and urinary AGT similarly in both sexes; however, the decrease in proteinuria was greater in the females. CONCLUSION During Ang II-dependent hypertension and HS diet, higher intrarenal renin-angiotensin system activation in males, as reflected by higher AGT gene expression and urinary excretion, indicates a mechanism for greater progression of high blood pressure and might explain the sex disparity in development of salt-sensitive hypertension.
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Affiliation(s)
- Vicky F Rands
- Department of Physiology, School of Medicine, Tulane University, 1430 Tulane Avenue, New Orleans, LA 70112, USA
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Ashek A, Menzies RI, Mullins LJ, Bellamy COC, Harmar AJ, Kenyon CJ, Flatman PW, Mullins JJ, Bailey MA. Activation of thiazide-sensitive co-transport by angiotensin II in the cyp1a1-Ren2 hypertensive rat. PLoS One 2012; 7:e36311. [PMID: 22558431 PMCID: PMC3338649 DOI: 10.1371/journal.pone.0036311] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 04/02/2012] [Indexed: 12/02/2022] Open
Abstract
Transgenic rats with inducible expression of the mouse Ren2 gene were used to elucidate mechanisms leading to the development of hypertension and renal injury. Ren2 transgene activation was induced by administration of a naturally occurring aryl hydrocarbon, indole-3-carbinol (100 mg/kg/day by gastric gavage). Blood pressure and renal parameters were recorded in both conscious and anesthetized (butabarbital sodium; 120 mg/kg IP) rats at selected time-points during the development of hypertension. Hypertension was evident by the second day of treatment, being preceded by reduced renal sodium excretion due to activation of the thiazide-sensitive sodium-chloride co-transporter. Renal injury was evident after the first day of transgene induction, being initially limited to the pre-glomerular vasculature. Mircoalbuminuria and tubuloinsterstitial injury developed once hypertension was established. Chronic treatment with either hydrochlorothiazide or an AT1 receptor antagonist normalized sodium reabsorption, significantly blunted hypertension and prevented renal injury. Urinary aldosterone excretion was increased ∼20 fold, but chronic mineralocorticoid receptor antagonism with spironolactone neither restored natriuretic capacity nor prevented hypertension. Spironolactone nevertheless ameliorated vascular damage and prevented albuminuria. This study finds activation of sodium-chloride co-transport to be a key mechanism in angiotensin II-dependent hypertension. Furthermore, renal vascular injury in this setting reflects both barotrauma and pressure-independent pathways associated with direct detrimental effects of angiotensin II and aldosterone.
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Affiliation(s)
- Ali Ashek
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | - Robert I. Menzies
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | - Linda J. Mullins
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | | | - Anthony J. Harmar
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | - Christopher J. Kenyon
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | - Peter W. Flatman
- Centre for Integrative Physiology, The University of Edinburgh, Edinburgh, United Kingdom
| | - John J. Mullins
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | - Matthew A. Bailey
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Inhibition of soluble epoxide hydrolase improves the impaired pressure-natriuresis relationship and attenuates the development of hypertension and hypertension-associated end-organ damage in Cyp1a1-Ren-2 transgenic rats. J Hypertens 2012; 29:1590-601. [PMID: 21720266 DOI: 10.1097/hjh.0b013e328349062f] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE In the present study, we compared the effects of treatment with the novel soluble epoxide hydrolase (sEH) inhibitor (c-AUCB) with those of the AT1 receptor antagonist losartan on blood pressure (BP), autoregulation of renal blood flow (RBF) and on glomerular filtration rate (GFR) and the pressure-natriuresis relationship in response to stepwise reduction in renal arterial pressure (RAP) in Cyp1a1-Ren-2 transgenic rats. METHODS Hypertension was induced in Cyp1a1-Ren-2 rats through dietary administration for 11 days of the natural xenobiotic indole-3-carbinol (I3C) which activates the renin gene. Treatment with c-AUCB and losartan was started 48 h before initiating administration of the diet containing I3C. Rats were prepared for renal functional studies to evaluate in-vivo renal autoregulatory efficiency when RAP was gradually decreased by an aortic clamp. RESULTS I3C administration resulted in the development of severe hypertension which was associated with markedly lower basal RBF and GFR and substantially impaired autoregulatory efficiency as well as a suppression of the pressure-natriuresis relationship when compared with noninduced rats. Treatment with c-AUCB significantly decreased BP, improved autoregulatory efficiency of RBF and GFR and the slope of pressure-natriuresis relationship. Treatment with losartan completely prevented the impaired autoregulation and pressure-natriuresis relationship as well as the development of hypertension in I3C-induced rats. CONCLUSION Our present findings indicate that chronic treatment with the sEH inhibitor c-AUCB substantially attenuates the development of malignant hypertension in I3C-induced rats likely via improvement of the renal autoregulatory efficiency and the pressure-natriuresis relationship.
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Heijnen BF, Peutz-Kootstra CJ, Mullins JJ, Janssen BJ, Struijker-Boudier HA. Transient renin–angiotensin system stimulation in an early stage of life causes sustained hypertension in rats. J Hypertens 2011; 29:2369-80. [DOI: 10.1097/hjh.0b013e32834cfcf4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Dzirbíková Z, Kiss A, Okuliarová M, Kopkan L, Cervenka L. Expressions of per1 clock gene and genes of signaling peptides vasopressin, vasoactive intestinal peptide, and oxytocin in the suprachiasmatic and paraventricular nuclei of hypertensive TGR[mREN2]27 rats. Cell Mol Neurobiol 2011; 31:225-32. [PMID: 21061153 DOI: 10.1007/s10571-010-9612-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 09/28/2010] [Indexed: 12/19/2022]
Abstract
Hypertensive rats with multiple extra copies of the renin gene (TGR) exert an inverted circadian blood pressure (BP) profile. We investigated whether circadian oscillations in the hypothalamic suprachiasmatic nucleus (SCN), a main circadian oscillator, and the paraventricular nucleus (PVN), involved in BP control, are influenced in TGR rats. The expression of the clock gene per1, a marker of circadian timing, was measured in the SCN and PVN. Moreover, the expression of genes encoding vasopressin (AVP), vasoactive intestinal peptide (VIP) in the SCN, and AVP and oxytocin (OXT) in the PVN were studied by in situ hybridization. Expression of the per1 gene showed a distinct circadian rhythm in both the SCN and PVN with no differences observed between the TGR and control Sprague–Dawley (SD) rats. The expression of avp in the SCN was rhythmic in both strains and moderately higher in TGR than in SD rats while no significant changes were found in the PVN. The expression of vip in the SCN and oxt in the PVN did not differ between both strains. Our results may indicate that changes occurring downstream to the SCN are responsible for the development of the inverted BP rhythm in TGR hypertensive rats.
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Affiliation(s)
- Zuzana Dzirbíková
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University Bratislava, Slovak Republic
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Abstract
OBJECTIVE This study aimed to examine the effects of salt loading, with or without simultaneous angiotensin receptor blocker (ARB) treatment, on the systemic and tissue renin-angiotensin system (RAS) in spontaneously hypertensive rats (SHRs). METHOD Evaluation was performed early (4 weeks) in the course of salt loading in order to examine initial mediating events of cardiovascular and renal damage produced by salt excess. Four groups of rats were studied. Group 1 received regular rat chow (normal-salt diet); group 2 received normal-salt diet and an ARB (losartan, 30 mg/kg per day); group 3 received high-salt (8%) chow; and group 4 received high-salt diet and losartan. RESULTS High-salt diet increased systolic pressure to 193±1 mmHg compared to 180±2 in normal-salt diet group. Losartan reduced SBP in SHRs fed normal-salt diet but did not reduce SBP in the SHRs fed high-salt diet (192±2 mmHg). High-salt diet markedly increased urinary protein excretion from 27±4 to 64±13 mg/day and this increase was ameliorated by losartan (40±9 mg/day). In SHRs on high-salt diet, plasma angiotensin II concentration increased three to four-fold, whereas urinary angiotensinogen excretion increased 10-fold; and these changes were significantly reduced by losartan. High-salt diet accelerated glomerular injury and interstitial fibrosis in SHRs which were reduced by losartan. CONCLUSION These results demonstrate that the activity of RAS was either not suppressed or, even augmented, after 4 weeks of salt loading despite high salt intake and increased SBP. The data suggest that an augmented intrarenal RAS during high-salt diet may contribute to the development of renal injury in this experimental model.
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Honetschlägerová Z, Husková Z, Vaňourková Z, Sporková A, Kramer HJ, Hwang SH, Tsai HJ, Hammock BD, Imig JD, Červenka L, Kopkan L. Renal mechanisms contributing to the antihypertensive action of soluble epoxide hydrolase inhibition in Ren-2 transgenic rats with inducible hypertension. J Physiol 2011; 589:207-19. [PMID: 21078594 PMCID: PMC3039270 DOI: 10.1113/jphysiol.2010.199505] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 11/09/2010] [Indexed: 01/01/2023] Open
Abstract
In the present study, we examined the effects of soluble epoxide hydrolase (sEH) inhibition on the development of angiotensin II-dependent hypertension and on renal function in transgenic rats with inducible expression of the mouse renin gene (strain name Cyp1a1-Ren-2). Hypertension was induced in these rats by indole-3-carbinol (I3C; 0.3% in the diet) for 12 days. The sEH inhibitor cis-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (c-AUCB) was given in two doses (13 or 26 mg l-1) in drinking water. Blood pressure (BP), body weight (BW) and renal excretory parameters were monitored in conscious animals during the experiment. Renal haemodynamics was assessed at the end of treatment in anaesthetized rats. I3C administration resulted in severe hypertension with a rise in systolic BP from 118 ± 2 to 202 ± 3 mmHg, a loss of BW from 266 ± 5 to 228 ± 4 g and a rise in proteinuria from 14 ± 2 to 34 ± 3 mg day-1. Both doses of c-AUCB significantly attenuated the development of hypertension (systolic BP of 181 ± 4 and 176 ± 4 mmHg, respectively), the loss in BW (256 ± 4 and 259 ± 3 g, respectively) and the degree of proteinuria (27 ± 2 and 25 ± 3 mg day-1, respectively) to a similar extent. Moreover, c-AUCB prevented the reduction in renal plasma flow (5.4 ± 0.4 vs. 4.6 ± 0.3 ml min-1 g-1) and significantly increased sodium excretion (0.84 ± 0.16 vs. 0.38 ± 0.08 μmol min-1 g-1) during I3C administration. These data suggest that the oral administration of c-AUCB displays antihypertensive effects in Ren-2 transgenic rats with inducible malignant hypertension via an improvement of renal function.
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Affiliation(s)
- Zuzana Honetschlägerová
- Department of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
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Kujal P, Chábová VČ, Vernerová Z, Walkowska A, Kompanowska-Jezierska E, Sadowski J, Vaňourková Z, Husková Z, Opočenský M, Škaroupková P, Schejbalová S, Kramer HJ, Rakušan D, Malý J, Netuka I, Vaněčková I, Kopkan L, Červenka L. Similar renoprotection after renin-angiotensin-dependent and -independent antihypertensive therapy in 5/6-nephrectomized Ren-2 transgenic rats: are there blood pressure-independent effects? Clin Exp Pharmacol Physiol 2010; 37:1159-69. [DOI: 10.1111/j.1440-1681.2010.05453.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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