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Barros CC, Schadock I, Sihn G, Rother F, Xu P, Popova E, Lapidus I, Plehm R, Heuser A, Todiras M, Bachmann S, Alenina N, Araujo RC, Pesquero JB, Bader M. Chronic Overexpression of Bradykinin in Kidney Causes Polyuria and Cardiac Hypertrophy. Front Med (Lausanne) 2018; 5:338. [PMID: 30560131 PMCID: PMC6287039 DOI: 10.3389/fmed.2018.00338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 11/16/2018] [Indexed: 01/06/2023] Open
Abstract
Acute intra-renal infusion of bradykinin increases diuresis and natriuresis via inhibition of vasopressin activity. However, the consequences of chronically increased bradykinin in the kidneys have not yet been studied. A new transgenic animal model producing an excess of bradykinin by proximal tubular cells (KapBK rats) was generated and submitted to different salt containing diets to analyze changes in blood pressure and other cardiovascular parameters, urine excretion, and composition, as well as levels and expression of renin-angiotensin system components. Despite that KapBK rats excrete more urine and sodium, they have similar blood pressure as controls with the exception of a small increase in systolic blood pressure (SBP). However, they present decreased renal artery blood flow, increased intrarenal expression of angiotensinogen, and decreased mRNA expression of vasopressin V1A receptor (AVPR1A), suggesting a mechanism for the previously described reduction of renal vasopressin sensitivity by bradykinin. Additionally, reduced heart rate variability (HRV), increased cardiac output and frequency, and the development of cardiac hypertrophy are the main chronic effects observed in the cardiovascular system. In conclusion: (1) the transgenic KapBK rat is a useful model for studying chronic effects of bradykinin in kidney; (2) increased renal bradykinin causes changes in renin angiotensin system regulation; (3) decreased renal vasopressin sensitivity in KapBK rats is related to decreased V1A receptor expression; (4) although increased renal levels of bradykinin causes no changes in mean arterial pressure (MAP), it causes reduction in HRV, augmentation in cardiac frequency and output and consequently cardiac hypertrophy in rats after 6 months of age.
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Affiliation(s)
- Carlos C Barros
- Department of Nutrition, Federal University of Pelotas, Pelotas, Brazil
| | - Ines Schadock
- Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil.,Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Gabin Sihn
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | | | - Ping Xu
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Elena Popova
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Irina Lapidus
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Ralph Plehm
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Arnd Heuser
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Mihail Todiras
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | | | - Natalia Alenina
- Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Ronaldo C Araujo
- Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil
| | - Joao B Pesquero
- Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil
| | - Michael Bader
- Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Charite-University Medicine, Berlin, Germany.,Federal University of Minas Gerais, Belo Horizonte, Brazil.,Berlin Institute of Health (BIH), Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany.,Institute for Biology, University of Lübeck, Lübeck, Germany
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Kon V, Fogo A, Ichikawa I. Bradykinin causes selective efferent arteriolar dilation during angiotensin I converting enzyme inhibition. Kidney Int 1993; 44:545-50. [PMID: 8231026 DOI: 10.1038/ki.1993.279] [Citation(s) in RCA: 153] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We studied the effects of interruption of the renin-angiotensin system (RAS) in rats that were volume depleted by water deprivation for 48 hours (AWD) with/without furosemide (AWD + F), a condition known to activate RAS. Following baseline micropuncture, AWD rats (N = 6) were treated with a specific angiotensin II type 1 receptor antagonist (AIIRA; 4 mg/kg body wt bolus i.v. and then continuous infusion) and glomerular hemodynamics compared to those obtained during angiotensin I converting enzyme inhibitor treatment (ACEI; 24 mg/kg bolus i.v. and then continuous infusion). Systemic blood pressure decreased equally following AIIRA and ACEI. Single nephron glomerular filtration rate (SNGFR) increased from baseline following AIIRA (24 nl/min vs. 30, P < 0.025). While a decrease in efferent arteriolar resistance (RE) reduced glomerular capillary pressure (PGC; 67 mm Hg vs. 60, P < 0.05), this change in RE together with decrease in afferent arteriolar resistance (RA), enhanced glomerular plasma flow rate (QA; 80 nl/min vs. 111). Antagonizing angiotensin II receptor increased QA which, together with the tendency to increase glomerular capillary ultrafiltration coefficient, Kf, served to improve glomerular filtration. By contrast, although inhibition of the angiotensin I converting enzyme caused greater vasodilatation, no increase in SNGFR occurred. The lack of response in filtration after ACEI was due to a further fall in PGC to 52 mm Hg (P < 0.01 vs. AIIRA), reflecting profound reduction in RE. Since ACEI but not AIIRA potentiates bradykinin activity we examined effects of a specific bradykinin antagonist (Hoe).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- V Kon
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
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