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Kuneš J, Zicha J. Research on Experimental Hypertension in Prague (1966-2009). Physiol Res 2024; 73:S49-S66. [PMID: 39016152 DOI: 10.33549/physiolres.935425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024] Open
Abstract
The study of ontogenetic aspects of water and electrolyte metabolism performed in the Institute of Physiology (Czechoslovak Academy of Sciences) led to the research on the increased susceptibility of immature rats to salt-dependent forms of hypertension since 1966. Hemodynamic studies in developing rats paved the way to the evaluation of hemodynamic mechanisms during the development of genetic hypertension in SHR. A particular attention was focused on altered renal function and kidney damage in both salt and genetic hypertension with a special respect to renin-angiotensin system. Renal damage associated with hypertension progression was in the center of interest of several research groups in Prague. The alterations in ion transport, cell calcium handling and membrane structure as well as their relationship to abnormal lipid metabolism were studied in a close cooperation with laboratories in Munich, Glasgow, Montreal and Paris. The role of NO and oxidative stress in various forms of hypertension was a subject of a joint research with our Slovak colleagues focused mainly on NO-deficient hypertension elicited by chronic L-NAME administration. Finally, we adopted a method enabling us to evaluate the balance of vasoconstrictor and vasodilator mechanisms in BP maintenance. Using this method we demonstrated sympathetic hyperactivity and relative NO deficiency in rats with either salt-dependent or genetic hypertension. At the end of the first decennium of this century we were ready to modify our traditional approach towards modern trends in the research of experimental hypertension. Keywords: Salt-dependent hypertension o Genetic hypertension o Body fluids o Hemodynamics o Ion transport o Cell membrane structure and function o Renal function o Renin-angiotensin systems.
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Affiliation(s)
- J Kuneš
- Laboratory of Experimental Hypertension, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic.
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Jíchová Š, Gawryś O, Kompanowska-Jezierska E, Sadowski J, Melenovský V, Hošková L, Červenka L, Kala P, Veselka J, Čertíková Chábová V. Kidney Response to Chemotherapy-Induced Heart Failure: mRNA Analysis in Normotensive and Ren-2 Transgenic Hypertensive Rats. Int J Mol Sci 2021; 22:8475. [PMID: 34445179 PMCID: PMC8395170 DOI: 10.3390/ijms22168475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/21/2022] Open
Abstract
The aim of the present study was to perform kidney messenger ribonucleic acid (mRNA) analysis in normotensive, Hannover Sprague-Dawley (HanSD) rats and hypertensive, Ren-2 renin transgenic rats (TGR) after doxorubicin-induced heart failure (HF) with specific focus on genes that are implicated in the pathophysiology of HF-associated cardiorenal syndrome. We found that in both strains renin and angiotensin-converting enzyme mRNA expressions were upregulated indicating that the vasoconstrictor axis of the renin-angiotensin system was activated. We found that pre-proendothelin-1, endothelin-converting enzyme type 1 and endothelin type A receptor mRNA expressions were upregulated in HanSD rats, but not in TGR, suggesting the activation of endothelin system in HanSD rats, but not in TGR. We found that mRNA expression of cytochrome P-450 subfamily 2C23 was downregulated in TGR and not in HanSD rats, suggesting the deficiency in the intrarenal cytochrome P450-dependent pathway of arachidonic acid metabolism in TGR. These results should be the basis for future studies evaluating the pathophysiology of cardiorenal syndrome secondary to chemotherapy-induced HF in order to potentially develop new therapeutic approaches.
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Affiliation(s)
- Šárka Jíchová
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 14021 Prague, Czech Republic; (Š.J.); (L.Č.); (P.K.)
| | - Olga Gawryś
- Department of Renal and Body Fluid Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, PL02-106 Warsaw, Poland; (O.G.); (E.K.-J.); (J.S.)
| | - Elżbieta Kompanowska-Jezierska
- Department of Renal and Body Fluid Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, PL02-106 Warsaw, Poland; (O.G.); (E.K.-J.); (J.S.)
| | - Janusz Sadowski
- Department of Renal and Body Fluid Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, PL02-106 Warsaw, Poland; (O.G.); (E.K.-J.); (J.S.)
| | - Vojtěch Melenovský
- Department of Cardiology, Institute for Clinical and Experimental Medicine, 14021 Prague, Czech Republic; (V.M.); (L.H.)
| | - Lenka Hošková
- Department of Cardiology, Institute for Clinical and Experimental Medicine, 14021 Prague, Czech Republic; (V.M.); (L.H.)
| | - Luděk Červenka
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 14021 Prague, Czech Republic; (Š.J.); (L.Č.); (P.K.)
- Department of Pathophysiology, 2nd Faculty of Medicine, Charles University, 15006 Prague, Czech Republic
| | - Petr Kala
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 14021 Prague, Czech Republic; (Š.J.); (L.Č.); (P.K.)
- Department of Pathophysiology, 2nd Faculty of Medicine, Charles University, 15006 Prague, Czech Republic
- Department of Cardiology, University Hospital Motol and 2nd Faculty of Medicine, Charles University, 15006 Prague, Czech Republic;
| | - Josef Veselka
- Department of Cardiology, University Hospital Motol and 2nd Faculty of Medicine, Charles University, 15006 Prague, Czech Republic;
| | - Věra Čertíková Chábová
- Department of Nephrology, 1st Faculty of Medicine, Charles University, 12108 Prague, Czech Republic
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The endothelin system as target for therapeutic interventions in cardiovascular and renal disease. Clin Chim Acta 2020; 506:92-106. [DOI: 10.1016/j.cca.2020.03.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/05/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022]
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Vaněčková I, Hojná S, Kadlecová M, Kompanowska-Jezierska E, Zicha J. Distinct effects of bosentan on NO-dependent vasodilation and calcium influx in heterozygous Ren-2 transgenic rats on high-salt diet. Physiol Res 2019; 68:717-725. [PMID: 31424254 DOI: 10.33549/physiolres.934192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Our studies in hypertensive Ren-2 transgenic rats (TGR) demonstrated that chronic administration of atrasentan (ETA receptor antagonist) decreased blood pressure by reduced Ca2+ influx through L-type voltage-dependent calcium channels (L-VDCC) and attenuated angiotensin II-dependent vasoconstriction. We were interested whether bosentan (nonselective ET(A)/ET(B) receptor antagonist) would have similar effects. Young 4-week-old (preventive study) and adult 8-week-old (therapeutic study) heterozygous TGR and their normotensive Hannover Sprague-Dawley (HanSD) controls were fed normal-salt (NS, 0.6 % NaCl) or high-salt (HS, 2 % NaCl) diet for 8 weeks. An additional group of TGR fed HS was treated with bosentan (100 mg/kg/day). Bosentan had no effect on BP of TGR fed high-salt diet in both the preventive and therapeutic studies. There was no difference in the contribution of angiotensin II-dependent and sympathetic vasoconstriction in bosentan-treated TGR compared to untreated TGR under the condition of high-salt intake. However, bosentan significantly reduced NO-dependent vasodilation and nifedipine-sensitive BP component in TGR on HS diet. A highly important correlation of nifedipine-induced BP change and the BP after L-NAME administration was demonstrated. Although bosentan did not result in any blood pressure lowering effects, it substantially influenced NO-dependent vasodilation and calcium influx through L-VDCC in the heterozygous TGR fed HS diet. A significant correlation of nifedipine-induced BP change and the BP after L-NAME administration suggests an important role of nitric oxide in the closure of L-type voltage dependent calcium channels.
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Affiliation(s)
- I Vaněčková
- Department of Experimental Hypertension, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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Morales-Loredo H, Jones D, Barrera A, Mendiola PJ, Garcia J, Pace C, Murphy M, Kanagy NL, Gonzalez Bosc LV. A dual blocker of endothelin A/B receptors mitigates hypertension but not renal dysfunction in a rat model of chronic kidney disease and sleep apnea. Am J Physiol Renal Physiol 2019; 316:F1041-F1052. [PMID: 30810064 DOI: 10.1152/ajprenal.00018.2019] [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: 12/13/2022] Open
Abstract
Obstructive sleep apnea is characterized by recurrent episodes of pharyngeal collapse during sleep, resulting in intermittent hypoxia (IH), and is associated with a high incidence of hypertension and accelerated renal failure. In rodents, endothelin (ET)-1 contributes to IH-induced hypertension, and ET-1 levels inversely correlate with glomerular filtration rate in patients with end-stage chronic kidney disease (CKD). Therefore, we hypothesized that a dual ET receptor antagonist, macitentan (Actelion Pharmaceuticals), will attenuate and reverse hypertension and renal dysfunction in a rat model of combined IH and CKD. Male Sprague-Dawley rats received one of three diets (control, 0.2% adenine, and 0.2% adenine + 30 mg·kg-1·day-1 macitentan) for 2 wk followed by 2 wk of recovery diet. Rats were then exposed for 4 wk to air or IH (20 short exposures/h to 5% O2-5% CO2 7 h/day during sleep). Macitentan prevented the increases in mean arterial blood pressure caused by CKD, IH, and the combination of CKD + IH. However, macitentan did not improve kidney function, fibrosis, and inflammation. After CKD was established, rats were exposed to air or IH for 2 wk, and macitentan feeding continued for 2 more wk. Macitentan reversed the hypertension in IH, CKD, and CKD + IH groups without improving renal function. Our data suggest that macitentan could be an effective antihypertensive in patients with CKD and irreversible kidney damage as a way to protect the heart, brain, and eyes from elevated arterial pressure, but it does not reverse toxin-induced tubule atrophy.
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Affiliation(s)
- Humberto Morales-Loredo
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - David Jones
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Adelaeda Barrera
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Perenkita J Mendiola
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Joshua Garcia
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Carolyn Pace
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Minerva Murphy
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Nancy L Kanagy
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Laura V Gonzalez Bosc
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
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Vaněčková I, Hojná S, Kadlecová M, Vernerová Z, Kopkan L, Červenka L, Zicha J. Renoprotective effects of ET(A) receptor antagonists therapy in experimental non-diabetic chronic kidney disease: Is there still hope for the future? Physiol Res 2018; 67:S55-S67. [PMID: 29947528 DOI: 10.33549/physiolres.933898] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic kidney disease (CKD) is a life-threatening disease arising as a frequent complication of diabetes, obesity and hypertension. Since it is typically undetected for long periods, it often progresses to end-stage renal disease. CKD is characterized by the development of progressive glomerulosclerosis, interstitial fibrosis and tubular atrophy along with a decreased glomerular filtration rate. This is associated with podocyte injury and a progressive rise in proteinuria. As endothelin-1 (ET-1) through the activation of endothelin receptor type A (ET(A)) promotes renal cell injury, inflammation, and fibrosis which finally lead to proteinuria, it is not surprising that ET(A) receptors antagonists have been proven to have beneficial renoprotective effects in both experimental and clinical studies in diabetic and non-diabetic CKD. Unfortunately, fluid retention encountered in large clinical trials in diabetic CKD led to the termination of these studies. Therefore, several advances, including the synthesis of new antagonists with enhanced pharmacological activity, the use of lower doses of ET antagonists, the addition of diuretics, plus simply searching for distinct pathological states to be treated, are promising targets for future experimental studies. In support of these approaches, our group demonstrated in adult subtotally nephrectomized Ren-2 transgenic rats that the addition of a diuretic on top of renin-angiotensin and ET(A) blockade led to a further decrease of proteinuria. This effect was independent of blood pressure which was normalized in all treated groups. Recent data in non-diabetic CKD, therefore, indicate a new potential for ET(A) antagonists, at least under certain pathological conditions.
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Affiliation(s)
- I Vaněčková
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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Endothelin A receptor blocker atrasentan lowers blood pressure by the reduction of nifedipine-sensitive calcium influx in Ren-2 transgenic rats fed a high-salt diet. J Hypertens 2015; 33:161-9. [DOI: 10.1097/hjh.0000000000000357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kohan DE, Barton M. Endothelin and endothelin antagonists in chronic kidney disease. Kidney Int 2014; 86:896-904. [PMID: 24805108 PMCID: PMC4216619 DOI: 10.1038/ki.2014.143] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 01/31/2014] [Accepted: 02/06/2014] [Indexed: 01/10/2023]
Abstract
The incidence and prevalence of chronic kidney disease (CKD), with diabetes and hypertension accounting for the majority of cases, is on the rise, with up to 160 million individuals worldwide predicted to be affected by 2020. Given that current treatment options, primarily targeted at the renin-angiotensin system, only modestly slow down progression to end-stage renal disease, the urgent need for additional effective therapeutics is evident. Endothelin-1 (ET-1), largely through activation of endothelin A receptors, has been strongly implicated in renal cell injury, proteinuria, inflammation, and fibrosis leading to CKD. Endothelin receptor antagonists (ERAs) have been demonstrated to ameliorate or even reverse renal injury and/or fibrosis in experimental models of CKD, whereas clinical trials indicate a substantial antiproteinuric effect of ERAs in diabetic and nondiabetic CKD patients even on top of maximal renin-angiotensin system blockade. This review summarizes the role of ET in CKD pathogenesis and discusses the potential therapeutic benefit of targeting the ET system in CKD, with attention to the risks and benefits of such an approach.
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Affiliation(s)
- Donald E. Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, UT
| | - Matthias Barton
- Molecular Internal Medicine, University of Zürich, 8057 Zürich, Switzerland
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Abstract
In the past decade, research has advanced our understanding how endothelin contributes to proteinuria and glomerulosclerosis. Data from pre-clinical and clinical studies now provide evidence that proteinuric diseases such as focal segmental glomerulosclerosis and diabetic nephropathy as well as hypertension nephropathy are sensitive to treatment with endothelin receptor antagonists (ERAs). Like blockade of the renin-angiotensin system, ERA treatment-under certain conditions-may even cause disease regression, effects that could be achieved on top of renin-angiotensin-aldosterone system blockade, suggesting independent therapeutic mechanisms by which ERAs convey nephroprotection. Beneficial effects of ERAs on podocyte function, which is essential to maintain the glomerular filtration barrier, have been identified as one of the key mechanisms by which inhibition of the endothelin ETA receptor ameliorates renal structure and function. In this article, we will review pre-clinical studies demonstrating a causal role for endothelin in proteinuric chronic kidney disease (with a particular focus on functional and structural integrity of podocytes in vitro and in vivo). We will also review the evidence suggesting a therapeutic benefit of ERA treatment on the functional integrity of podocytes in humans.
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Affiliation(s)
- Matthias Barton
- Molecular Internal Medicine, University of Zürich, Zürich, Switzerland
| | - Pierre-Louis Tharaux
- INSERM and Université Paris Descartes, Sorbonne Paris Cité, Paris Cardiovascular Centre, Paris, France
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Vanecková I, Kujal P, Husková Z, Vanourková Z, Vernerová Z, Certíková Chábová V, karoupková P, Kramer HJ, Tesar V, Cervenka L. Effects of Combined Endothelin A Receptor and Renin-Angiotensin System Blockade on the Course of End-Organ Damage in 5/6 Nephrectomized Ren-2 Hypertensive Rats. ACTA ACUST UNITED AC 2012; 35:382-92. [DOI: 10.1159/000336823] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 01/26/2012] [Indexed: 01/13/2023]
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Rakusan D, Kujal P, Kramer HJ, Husková Z, Vanourková Z, Vernerová Z, Mrázová I, Thumová M, Cervenka L, Vanecková I. Persistent antihypertensive effect of aliskiren is accompanied by reduced proteinuria and normalization of glomerular area in Ren-2 transgenic rats. Am J Physiol Renal Physiol 2010; 299:F758-66. [PMID: 20668096 DOI: 10.1152/ajprenal.00259.2010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effects of the human renin inhibitor aliskiren on blood pressure (BP), end-organ damage, proteinuria, and tissue and plasma angiotensin (ANG) II levels in young and adult heterozygous Ren-2 transgenic rats (TGR) were evaluated and compared with the effect of the ANG type 1 (AT(1)) receptor blocker losartan during treatment and after 12 days after the withdrawal of drug treatments. BP was monitored by telemetry from the age of 32 days on (young rats) and at 100 days (adult rats). Aliskiren (10 mg·kg(-1)·day(-1) in osmotic minipumps) or losartan (5 mg·kg(-1)·day(-1) in drinking water) treatment was applied for 28 days in young rats and for 70 days in adult rats. In young untreated TGR, severe hypertension rapidly evolved. Adult untreated TGR exhibited stable established hypertension. Both aliskiren and losartan fully prevented the development of hypertension and cardiac hypertrophy in young TGR and normalized BP and cardiac hypertrophy in adult TGR. After cessation of aliskiren treatment in both young and adult TGR BP and cardiac hypertrophy were persistently reduced, while after losartan withdrawal BP and cardiac hypertrophy rapidly increased. In adult aliskiren-treated rats proteinuria was significantly reduced compared with losartan (the effect persisting after withdrawal of treatment), and this decrease strongly correlated with normalization of glomerular size in these animals. In conclusion, aliskiren and losartan had similar antihypertensive effects during chronic treatment, but the antihypertensive and organoprotective effects of aliskiren were persistent even after the 12-day washout period. The durable effect on proteinuria can possibly be attributed to the normalization of glomerular morphology.
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Affiliation(s)
- Dan Rakusan
- Section of Nephrology, 1st Medical Faculty, Department of Medicine, Charles University, Prague, Czech Republic
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Abstract
PURPOSE OF REVIEW Endothelin is important in the development of cardiorenal disease. This review discusses recent developments in understanding endothelin's role in hypertension and chronic kidney disease (CKD). RECENT FINDINGS Endothelin-1 production is increased in hypertension and CKD. Endothelin-1 stimulates vasoconstriction, inflammation and fibrosis, thereby promoting hypertension, atherosclerosis and CKD. These effects are closely linked to angiotensin II and reactive oxygen species. In preclinical studies, endothelin receptor antagonists were effective in treating hypertension (particularly with endothelial dysfunction) and CKD. In preclinical studies, endothelin A-selective, as opposed to combined endothelin A and B, receptor blockers have generally been more efficacious. Few clinical trials have been conducted in hypertension and/or kidney disease, partly due to concerns over side effects of testicular toxicity and fluid retention. Endothelin blockade reduces blood pressure in patients with resistant hypertension, with additional beneficial metabolic effects. Endothelin antagonism improves proteinuria in CKD (diabetic or not), particularly in patients taking inhibitors of angiotensin II action. SUMMARY Endothelin is a promising target in the treatment of resistant hypertension and CKD, with additional potential benefits on atherosclerosis and the metabolic syndrome. The nature and mechanisms of drug side effects require elucidation before the potential of this new class of drugs can be fully realized.
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Yang KM, Russell J, Lupu ME, Cho H, Li XF, Koutcher JA, Ling CC. Atrasentan (ABT-627) enhances perfusion and reduces hypoxia in a human tumor xenograft model. Cancer Biol Ther 2009; 8:1940-6. [PMID: 19717985 DOI: 10.4161/cbt.8.20.9595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The endothelin-1 antagonist, Atrasentan (ABT-627) was used to modify perfusion in the human tumor xenograft model, HT29, growing in nude mice. Atrasentan produced a significant increase in perfusion, as measured in vivo by Gd-DTPA DCE-MRI. Changes in tumor hypoxia were assessed by comparing the binding of two hypoxia tracers, pimonidazole and EF5 given before and after Atrasentan administration. In vehicle-treated controls, the distribution of EF5 and pimonidazole was very similar. However, Atrasentan treatment was associated with decreased uptake of the second hypoxia tracer (EF5), relative to the first (pimonidazole). Although Atrasentan had no independent effect on the growth of HT29 tumors, Atrasentan combined with 20 Gy radiation led to a modest but significant increase in tumor growth delay compared to radiation alone.
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Affiliation(s)
- Kwang Mo Yang
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
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Reduction of oxidative stress does not attenuate the development of angiotensin II-dependent hypertension in Ren-2 transgenic rats. Vascul Pharmacol 2009; 51:175-81. [PMID: 19539780 DOI: 10.1016/j.vph.2009.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 05/04/2009] [Accepted: 06/03/2009] [Indexed: 01/07/2023]
Abstract
Results of our previous studies have suggested that enhanced generation of superoxide (O2(-)) may contribute to the pathophysiology of hypertension in Ren-2 transgenic rats (TGR). The present study was performed to evaluate in TGR the effects of chronic treatment with the O2(-) scavenger tempol and the antioxidant apocynin on the development of hypertension. Systolic blood pressure (SBP) was monitored from 30 to 99 days of age in TGR and in normotensive Hannover Sprague-Dawley (HanSD) rats. At the end of the experiment, urinary protein and 8-isoprostane excretion were determined and angiotensin II (ANG II) and malondialdehyde (MDA) levels were measured in kidney and cardiac tissues. Cardiac hypertrophy was assessed as the ratio of left heart ventricle weight to tibia length (LVW/TL). Although tempol and apocynin treatment in TGR significantly decreased 8-isoprostane excretion and MAD tissue concentrations as compared with untreated TGR, it did not alter the course of SBP, LVW/TL ratio, proteinuria or ANG II levels that were enhanced as compared with HanSD rats. Our data suggest that the development of hypertension in TGR is clearly ANG II-dependent but the contribution of oxidative stress to the development of hypertension in this model appears to be negligible.
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Endothelin receptor blockade does not affect blood pressure or angiotensin II levels in CYP1A1-Ren-2 transgenic rats with acutely induced hypertension. Vascul Pharmacol 2009; 50:194-9. [DOI: 10.1016/j.vph.2009.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 12/08/2008] [Accepted: 01/21/2009] [Indexed: 11/22/2022]
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Barton M. Reversal of proteinuric renal disease and the emerging role of endothelin. ACTA ACUST UNITED AC 2008; 4:490-501. [PMID: 18648345 DOI: 10.1038/ncpneph0891] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 06/05/2008] [Indexed: 01/18/2023]
Abstract
Proteinuria is a major long-term clinical consequence of diabetes and hypertension, conditions that lead to progressive loss of functional renal tissue and, ultimately, end-stage renal disease. Proteinuria is also a strong predictor of cardiovascular events. Convincing preclinical and clinical evidence exists that proteinuria and the underlying glomerulosclerosis are reversible processes. This Review outlines the mechanisms involved in the development of glomerulosclerosis--particularly those responsible for podocyte injury--with an emphasis on the potential capacity of endothelin receptor blockade to reverse this process. There is strong evidence that endothelin-1, a peptide with growth-promoting and vasoconstricting properties, has a central role in the pathogenesis of proteinuria and glomerulosclerosis, which is mediated via activation of the ET(A) receptor. Several antiproteinuric drugs, including angiotensin-converting-enzyme inhibitors, angiotensin receptor antagonists, statins and certain calcium channel blockers, inhibit the formation of endothelin-1. Preclinical studies have demonstrated that endothelin receptor antagonists can reverse proteinuric renal disease and glomerulosclerosis, and preliminary studies in humans with renal disease have shown that these drugs have remarkable antiproteinuric effects that are additive to those of standard antiproteinuric therapy. Additional clinical studies are needed.
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Affiliation(s)
- Matthias Barton
- Department of Internal Medicine, Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich, Zürich, Switzerland.
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