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Potthoff SA, Stamer S, Grave K, Königshausen E, Sivritas SH, Thieme M, Mori Y, Woznowski M, Rump LC, Stegbauer J. Chronic p38 mitogen-activated protein kinase inhibition improves vascular function and remodeling in angiotensin II-dependent hypertension. J Renin Angiotensin Aldosterone Syst 2016; 17:17/3/1470320316653284. [PMID: 27407119 PMCID: PMC5843849 DOI: 10.1177/1470320316653284] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/19/2016] [Indexed: 11/16/2022] Open
Abstract
Introduction: An excess of angiotensin II (Ang II) causes hypertension and vascular injury. Activation of mitogen-activated protein kinase p38 (p38-MAPK) plays a substantial role in Ang II-dependent organ damage. Recently, we showed that p38-MAPK activation regulates the pressor response to Ang II. This study evaluates the effect of chronic p38-MAPK inhibition in Ang II-dependent hypertension. Materials and methods: C57Bl/6J mice were infused with Ang II for 14 days and either treated with the p38-MAPK inhibitor BIRB796 (50 mg/kg/day) or the vehicle as the control. We assessed vascular function in the aorta and isolated perfused kidneys. Results: Chronic p38-MAPK inhibition did not alter blood pressure at the baseline, but attenuated Ang II-induced hypertension significantly (baseline: 122 ± 2 versus 119 ± 4 mmHg; Ang II: 173 ± 3 versus 155 ± 3 mmHg; p < 0.001). In addition, BIRB796 treatment improved vascular remodeling by reducing the aortic media-to-lumen ratio and decreasing the expression of the membrane metalloproteinases (MMP) MMP-1 and MMP-9. Moreover, renal vascular dysfunction induced by chronic Ang II infusion was significantly ameliorated in the BIRP796-treated mice. Acute p38-MAPK inhibition also improved vascular function in the aorta and kidneys of Ang II-treated mice, highlighting the important role of p38-MAPK activation in the pathogenesis of vascular dysfunction. Conclusions: Our findings indicated there is an important role for p38-MAPK in regulating blood pressure and vascular injury, and highlighted its potential as a pharmaceutical target.
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Affiliation(s)
- S A Potthoff
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - S Stamer
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - K Grave
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - E Königshausen
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - S H Sivritas
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - M Thieme
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Y Mori
- Department of Nuclear Medicine, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - M Woznowski
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - L C Rump
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - J Stegbauer
- Department of Nephrology, University Hospital Düsseldorf, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
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Sivritas SH, Ploth DW, Fitzgibbon WR. Blockade of renal medullary bradykinin B2 receptors increases tubular sodium reabsorption in rats fed a normal-salt diet. Am J Physiol Renal Physiol 2008; 295:F811-7. [PMID: 18632797 PMCID: PMC2536883 DOI: 10.1152/ajprenal.90225.2008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 07/11/2008] [Indexed: 11/22/2022] Open
Abstract
The present study was performed to test the hypothesis that under normal physiological conditions and/or during augmentation of kinin levels, intrarenal kinins act on medullary bradykinin B(2) (BKB(2)) receptors to acutely increase papillary blood flow (PBF) and therefore Na(+) excretion. We determined the effect of acute inner medullary interstitial (IMI) BKB(2) receptor blockade on renal hemodynamics and excretory function in rats fed either a normal (0.23%)- or a low (0.08%)-NaCl diet. For each NaCl diet, two groups of rats were studied. Baseline renal hemodynamic and excretory function were determined during IMI infusion of 0.9% NaCl into the left kidney. The infusion was then either changed to HOE-140 (100 microg.kg(-1).h(-1), treated group) or maintained with 0.9% NaCl (time control group), and the parameters were again determined. In rats fed a normal-salt diet, HOE-140 infusion decreased left kidney Na(+) excretion (urinary Na(+) extraction rate) and fractional Na(+) excretion by 40 +/- 5% and 40 +/- 4%, respectively (P < 0.01), but did not alter glomerular filtration rate, inner medullary blood flow (PBF), or cortical blood flow. In rats fed a low-salt diet, HOE-140 infusion did not alter renal regional hemodynamics or excretory function. We conclude that in rats fed a normal-salt diet, kinins act tonically via medullary BKB(2) receptors to increase Na(+) excretion independent of changes in inner medullary blood flow.
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Affiliation(s)
- Sema-Hayriye Sivritas
- Department of Medicine, Division of Nephrology, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA
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