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Himmerkus N, Plain A, Marques RD, Sonntag SR, Paliege A, Leipziger J, Bleich M. AVP dynamically increases paracellular Na+ permeability and transcellular NaCl transport in the medullary thick ascending limb of Henle’s loop. Pflugers Arch 2016; 469:149-158. [DOI: 10.1007/s00424-016-1915-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 01/08/2023]
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Boldt C, Röschel T, Himmerkus N, Plain A, Bleich M, Labes R, Blum M, Krause H, Magheli A, Giesecke T, Mutig K, Rothe M, Weldon SM, Dragun D, Schunck WH, Bachmann S, Paliege A. Vasopressin lowers renal epoxyeicosatrienoic acid levels by activating soluble epoxide hydrolase. Am J Physiol Renal Physiol 2016; 311:F1198-F1210. [PMID: 27681558 DOI: 10.1152/ajprenal.00062.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 09/19/2016] [Indexed: 11/22/2022] Open
Abstract
Activation of the thick ascending limb (TAL) Na+-K+-2Cl- cotransporter (NKCC2) by the antidiuretic hormone arginine vasopressin (AVP) is an essential mechanism of renal urine concentration and contributes to extracellular fluid and electrolyte homeostasis. AVP effects in the kidney are modulated by locally and/or by systemically produced epoxyeicosatrienoic acid derivates (EET). The relation between AVP and EET metabolism has not been determined. Here, we show that chronic treatment of AVP-deficient Brattleboro rats with the AVP V2 receptor analog desmopressin (dDAVP; 5 ng/h, 3 days) significantly lowered renal EET levels (-56 ± 3% for 5,6-EET, -50 ± 3.4% for 11,12-EET, and -60 ± 3.7% for 14,15-EET). The abundance of the principal EET-degrading enzyme soluble epoxide hydrolase (sEH) was increased at the mRNA (+160 ± 37%) and protein levels (+120 ± 26%). Immunohistochemistry revealed dDAVP-mediated induction of sEH in connecting tubules and cortical and medullary collecting ducts, suggesting a role of these segments in the regulation of local interstitial EET signals. Incubation of murine kidney cell suspensions with 1 μM 14,15-EET for 30 min reduced phosphorylation of NKCC2 at the AVP-sensitive threonine residues T96 and T101 (-66 ± 5%; P < 0.05), while 14,15-DHET had no effect. Concomitantly, isolated perfused cortical thick ascending limb pretreated with 14,15-EET showed a 30% lower transport current under high and a 70% lower transport current under low symmetric chloride concentrations. In summary, we have shown that activation of AVP signaling stimulates renal sEH biosynthesis and enzyme activity. The resulting reduction of EET tissue levels may be instrumental for increased NKCC2 transport activity during AVP-induced antidiuresis.
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Affiliation(s)
- Christin Boldt
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Tom Röschel
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Nina Himmerkus
- Department of Physiology, Christian-Albrechts-University, Kiel, Germany
| | - Allein Plain
- Department of Physiology, Christian-Albrechts-University, Kiel, Germany
| | - Markus Bleich
- Department of Physiology, Christian-Albrechts-University, Kiel, Germany
| | - Robert Labes
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Maximilian Blum
- Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Hans Krause
- Department of Urology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ahmed Magheli
- Department of Urology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Torsten Giesecke
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Kerim Mutig
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Steven M Weldon
- Boehringer Ingelheim Pharmaceuticals, Ridgefield, Connecticut
| | - Duska Dragun
- Department of Nephrology, Charité-Universitätsmedizin Berlin, Berlin, Germany; and.,Berlin Institute of Health, Berlin, Germany
| | | | - Sebastian Bachmann
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Alexander Paliege
- Department of Nephrology, Charité-Universitätsmedizin Berlin, Berlin, Germany; and .,Berlin Institute of Health, Berlin, Germany
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Hultström M. Neurohormonal interactions on the renal oxygen delivery and consumption in haemorrhagic shock-induced acute kidney injury. Acta Physiol (Oxf) 2013; 209:11-25. [PMID: 23837642 DOI: 10.1111/apha.12147] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 07/02/2013] [Accepted: 07/04/2013] [Indexed: 12/14/2022]
Abstract
Haemorrhagic shock is a common cause of acute kidney injury (AKI), which is a major risk factor for developing chronic kidney disease. The mechanism is superficially straightforward. An arterial pressure below the kidney's autoregulatory region leads to a direct reduction in filtration pressure and perfusion, which in turn cause renal failure with reduced glomerular filtration rate and AKI because of hypoxia. However, the kidney's situation is further worsened by the hormonal and neural reactions to reduced perfusion pressure. There are three major systems working to maintain arterial pressure in shock: sympathetic signalling, the renin-angiotensin system and vasopressin. These work to retain electrolytes and water and to increase peripheral resistance and cardiac output. In the kidney, the increased electrolyte reabsorption consumes oxygen. At the same time, at the signalling level seen in shock, all of these hormones reduce renal perfusion and thereby oxygen delivery. This creates an exaggerated hypoxic situation that is liable to worsen the AKI. The present review will examine this mechanistic background and identify a number of areas that require further studies. At this time, the ideal treatment of haemorrhagic shock appears to be slow fluid resuscitation, possibly with hyperosmolar sodium, low chloride and no artificial colloids. From the standpoint of the kidney, renin-angiotensin system inhibitors appear fruitful for further study.
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Affiliation(s)
- M Hultström
- Unit for Integrative Physiology, Department of Medical Cellbiology, Uppsala University, Uppsala, Sweden; Anaesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
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Poulsen SB, Kim YH, Frøkiær J, Nielsen S, Christensen BM. Long-term vasopressin-V2-receptor stimulation induces regulation of aquaporin 4 protein in renal inner medulla and cortex of Brattleboro rats. Nephrol Dial Transplant 2013; 28:2058-65. [DOI: 10.1093/ndt/gft088] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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