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Dilken O, Ince C, Kapucu A, Heeman PM, Ergin B. Furosemide exacerbated the impairment of renal function, oxygenation and medullary damage in a rat model of renal ischemia/reperfusion induced AKI. Intensive Care Med Exp 2023; 11:25. [PMID: 37121963 PMCID: PMC10149155 DOI: 10.1186/s40635-023-00509-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/17/2023] [Indexed: 05/02/2023] Open
Abstract
BACKGROUND Perioperative acute kidney injury (AKI) caused by ischemia-reperfusion (IR) is a significant contributor to mortality and morbidity after major surgery. Furosemide is commonly used in postoperative patients to promote diuresis and reduce tissue edema. However, the effects of furosemide on renal microcirculation, oxygenation and function are poorly understood during perioperative period following ischemic insult. Herein, we investigated the effects of furosemide in rats subjected IR insult. METHODS 24 Wistar albino rats were divided into 4 groups, with 6 in each; Sham-operated Control (C), Control + Furosemide (C + F), ischemia/reperfusion (IR), and IR + F. After induction of anesthesia (BL), supra-aortic occlusion was applied to IR and IR + F groups for 45 min followed by ongoing reperfusion for 15 min (T1) and 2 h (T2). Furosemide infusion was initiated simultaneously in the intervention groups after ischemia. Renal blood flow (RBF), vascular resistance (RVR), oxygen delivery (DO2ren) and consumption (VO2ren), sodium reabsorption (TNa+), oxygen utilization efficiency (VO2/TNa+), cortical (CμO2) and medullary (MμO2) microvascular oxygen pressures, urine output (UO) and creatinine clearance (Ccr) were measured. Biomarkers of inflammation, oxidative and nitrosative stress were measured and kidneys were harvested for histological analysis. RESULTS IR significantly decreased RBF, mainly by increasing RVR, which was exacerbated in the IR + F group at T2 (2198 ± 879 vs 4233 ± 2636 dyne/s/cm5, p = 0.07). CμO2 (61.6 ± 6.8 vs 86 ± 6.6 mmHg) and MμO2 (51.1 ± 4.1 vs 68.7 ± 4.9 mmHg, p < 0.05) were both reduced after IR and did not improve by furosemide. Moreover, VO2/TNa+ increased in the IR + F group at T2 with respect to the IR group (IR: 3.3 ± 2 vs IR + F: 8.2 ± 10 p = 0.07) suggesting a possible deterioration of oxygen utilization. Ccr did not change, but plasma creatinine increased significantly in IR + F groups. Histopathology revealed widespread damage both in the cortex and medulla in IR, IR + F and C + F groups. CONCLUSION Renal microvascular oxygenation, renal function, renal vascular resistance, oxygen utilization and damage were not improved by furosemide administration after IR insult. Our study suggests that furosemide may cause additional structural and functional impairment to the kidney following ischemic injury and should be used with caution.
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Affiliation(s)
- Olcay Dilken
- Laboratory of Translational Intensive Care, Department of Intensive Care Adult, Erasmus MC, University Medical Center Rotterdam, Erasmus University, Doctor Molewaterplein 40, 3015 GD, Rotterdam, The Netherlands
- Department of Intensive Care, Faculty of Medicine, University of Istanbul-Cerrahpasa, Istanbul, Turkey
| | - Can Ince
- Laboratory of Translational Intensive Care, Department of Intensive Care Adult, Erasmus MC, University Medical Center Rotterdam, Erasmus University, Doctor Molewaterplein 40, 3015 GD, Rotterdam, The Netherlands
| | - Aysegul Kapucu
- Department of Zoology, Faculty of Science, University of Istanbul, Istanbul, Turkey
| | - Paul M Heeman
- Department of Medical Technical Innovation & Development (MIO), Amsterdam University Medical Centre (UMC) Location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Bülent Ergin
- Laboratory of Translational Intensive Care, Department of Intensive Care Adult, Erasmus MC, University Medical Center Rotterdam, Erasmus University, Doctor Molewaterplein 40, 3015 GD, Rotterdam, The Netherlands.
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Ergin B, Akin S, Ince C. Kidney Microcirculation as a Target for Innovative Therapies in AKI. J Clin Med 2021; 10:4041. [PMID: 34575154 DOI: 10.3390/jcm10184041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/29/2021] [Accepted: 09/02/2021] [Indexed: 12/19/2022] Open
Abstract
Acute kidney injury (AKI) is a serious multifactorial conditions accompanied by the loss of function and damage. The renal microcirculation plays a crucial role in maintaining the kidney’s functional and structural integrity for oxygen and nutrient supply and waste product removal. However, alterations in microcirculation and oxygenation due to renal perfusion defects, hypoxia, renal tubular, and endothelial damage can result in AKI and the loss of renal function regardless of systemic hemodynamic changes. The unique structural organization of the renal microvasculature and the presence of autoregulation make it difficult to understand the mechanisms and the occurrence of AKI following disorders such as septic, hemorrhagic, or cardiogenic shock; ischemia/reperfusion; chronic heart failure; cardiorenal syndrome; and hemodilution. In this review, we describe the organization of microcirculation, autoregulation, and pathophysiological alterations leading to AKI. We then suggest innovative therapies focused on the protection of the renal microcirculation and oxygenation to prevent AKI.
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Abstract
The kidney is a highly metabolic organ that requires substantial adenosine triphosphate for the active transport required to maintain water and solute reabsorption. Aberrations in energy availability and energy utilization can lead to cellular dysfunction and death. Mitochondria are essential for efficient energy production. The pathogenesis of acute kidney injury is complex and varies with different types of injury. However, multiple distinct acute kidney injury syndromes share a common dysregulation of energy metabolism. Pathways of energy metabolism and mitochondrial dysfunction are emerging as critical drivers of acute kidney injury and represent new potential targets for treatment. This review shows the basic metabolic pathways that all cells depend on for life; describes how the kidney optimizes those pathways to meet its anatomic, physiologic, and metabolic needs; summarizes the importance of metabolic and mitochondrial dysfunction in acute kidney injury; and analyzes the mitochondrial processes that become dysregulated in acute kidney injury including mitochondrial dynamics, mitophagy, mitochondrial biogenesis, and changes in mitochondrial energy metabolism.
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Affiliation(s)
- Amanda J Clark
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Samir M Parikh
- Division of Nephrology, Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
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Maiden MJ, Otto S, Brealey JK, Finnis ME, Chapman MJ, Kuchel TR, Nash CH, Edwards J, Bellomo R. Structure and Function of the Kidney in Septic Shock. A Prospective Controlled Experimental Study. Am J Respir Crit Care Med 2017; 194:692-700. [PMID: 26967568 DOI: 10.1164/rccm.201511-2285oc] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE It is unclear how septic shock causes acute kidney injury (AKI) and whether this is associated with histological change. OBJECTIVES We aimed to determine the nature and extent of changes in renal structure and function over time in an ovine model of septic shock. METHODS Fifteen sheep were instrumented with a renal artery flow probe and renal vein cannula. Ten were given intravenous Escherichia coli to induce septic shock, and five acted as controls. Animals were mechanically ventilated for 48 hours, while receiving protocol-guided parenteral fluids and a norepinephrine infusion to maintain mean arterial pressure. Renal biopsies were taken every 24 hours or whenever animals were oliguric for 2 hours. A renal pathologist, blinded to tissue source, systematically quantified histological appearance by light and electron microscopy for 31 prespecified structural changes. MEASUREMENTS AND MAIN RESULTS Sheep given E. coli developed septic shock, oliguria, increased serum creatinine, and reduced creatinine clearance (AKI), but there were no changes over time in renal blood flow between groups (P > 0.30) or over time within groups (P > 0.50). Renal oxygen consumption increased only in nonseptic animals (P = 0.01), but there was no between-group difference in renal lactate flux (P > 0.50). There was little structural disturbance in all biopsies and, although some cellular appearances changed over time, the only difference between septic and nonseptic animals was mesangial expansion on electron microscopy. CONCLUSIONS In an intensive care-supported model of gram-negative septic shock, early AKI was not associated with changes in renal blood flow, oxygen delivery, or histological appearance. Other mechanisms must contribute to septic AKI.
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Affiliation(s)
- Matthew J Maiden
- 1 Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia.,2 Discipline of Acute Care Medicine, University of Adelaide, Adelaide, Australia
| | - Sophia Otto
- 3 Department of Pathology, SA Pathology, Adelaide, Australia
| | - John K Brealey
- 3 Department of Pathology, SA Pathology, Adelaide, Australia
| | - Mark E Finnis
- 1 Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia.,2 Discipline of Acute Care Medicine, University of Adelaide, Adelaide, Australia
| | - Marianne J Chapman
- 1 Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia.,2 Discipline of Acute Care Medicine, University of Adelaide, Adelaide, Australia
| | - Tim R Kuchel
- 4 Preclinical, Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Gilles Plains, Australia; and
| | - Coralie H Nash
- 2 Discipline of Acute Care Medicine, University of Adelaide, Adelaide, Australia
| | - Jason Edwards
- 1 Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia
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Bullen A, Liu ZZ, Hepokoski M, Li Y, Singh P. Renal Oxygenation and Hemodynamics in Kidney Injury. Nephron Clin Pract 2017; 137:260-263. [PMID: 28614837 DOI: 10.1159/000477830] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 12/26/2022] Open
Abstract
Acute kidney injury (AKI) continues to be a major therapeutic challenge. Despite significant advances made in cellular and molecular pathophysiology of AKI, major gaps in knowledge exist regarding the changes in renal hemodynamics and oxygenation in the early stages and through the continuum of AKI. Particular features of renal hemodynamics and oxygenation increase the susceptibility of the kidney to sustain injury due to oxygen demand-supply mismatch and also play an important role in the recovery and repair from AKI as well as the transition of AKI to chronic kidney disease. However, lack of well-established physiological biomarkers and noninvasive imaging techniques limit our understanding of the interactions between renal macro and microcirculation and tissue oxygenation in AKI. Advances in our ability to assess these parameters in preclinical and clinical AKI will enable the development of targeted therapeutics to improve clinical outcomes.
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Affiliation(s)
- Alexander Bullen
- Division of Nephrology-Hypertension, University of California, San Diego School of Medicine and VA San Diego Healthcare System, San Diego, CA, USA
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Post EH, Kellum JA, Bellomo R, Vincent JL. Renal perfusion in sepsis: from macro- to microcirculation. Kidney Int 2016; 91:45-60. [PMID: 27692561 DOI: 10.1016/j.kint.2016.07.032] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/01/2016] [Accepted: 07/07/2016] [Indexed: 12/16/2022]
Abstract
The pathogenesis of sepsis-associated acute kidney injury is complex and likely involves perfusion alterations, a dysregulated inflammatory response, and bioenergetic derangements. Although global renal hypoperfusion has been the main target of therapeutic interventions, its role in the development of renal dysfunction in sepsis is controversial. The implications of renal hypoperfusion during sepsis probably extend beyond a simple decrease in glomerular filtration pressure, and targeting microvascular perfusion deficits to maintain tubular epithelial integrity and function may be equally important. In this review, we provide an overview of macro- and microcirculatory dysfunction in experimental and clinical sepsis and discuss relationships with kidney oxygenation, metabolism, inflammation, and function.
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Affiliation(s)
- Emiel Hendrik Post
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - John A Kellum
- Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rinaldo Bellomo
- Centre for Integrated Critical Care, School of Medicine, The University of Melbourne, Parkville, Melbourne, Australia
| | - Jean-Louis Vincent
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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Post EH, Su F, Hosokawa K, Taccone FS, Herpain A, Creteur J, Vincent JL, De Backer D. Changes in kidney perfusion and renal cortex metabolism in septic shock: an experimental study. J Surg Res 2016; 207:145-154. [PMID: 27979471 DOI: 10.1016/j.jss.2016.08.083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/25/2016] [Accepted: 08/24/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND The etiology of renal dysfunction in sepsis is currently attributed to altered perfusion, microcirculatory abnormalities and cellular alterations. To clarify these mechanisms, we characterized the changes in renal perfusion and cortex metabolism in a large animal model of sepsis. METHODS We studied 12 adult female sheep randomized to peritonitis-induced sepsis (n = 8) or to sham procedure (n = 4). A flow probe was positioned around the renal artery to measure renal blood flow (RBF). Laser Doppler was used to measure regional flow in the kidney cortex and medulla. A microdialysis probe was inserted into the renal cortex to measure cortical glucose, lactate, and pyruvate. Fluid resuscitation was provided to keep pulmonary artery occlusion pressure at baseline levels. All animals were observed for 18 h. RESULTS Hypotension occurred after 9 h in the septic animals (P = 0.02 versus baseline). RBF and cortical flow were significantly lower than at baseline from 12 h in the septic animals (P = 0.01 and P = 0.03, respectively). Cortical lactate and pyruvate levels increased in the septic animals from 3 and from 6 h, respectively (both P = 0.02 versus baseline), and the L/P ratio from 15 h (P = 0.01). There was a correlation between cortical flow and cortical L/P ratio after shock onset (r = -0.60, P = 0.002) but not before. CONCLUSIONS In this peritonitis model, sepsis was associated with metabolic alterations that may reflect early induction of cortical glycolysis. Septic shock was associated with reduced renal perfusion and decreased cortical and medullary blood flow, followed by signs of anaerobic metabolism in the cortex when flow reductions became critical.
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Affiliation(s)
- Emiel Hendrik Post
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Fuhong Su
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Koji Hosokawa
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Antoine Herpain
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Jacques Creteur
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean-Louis Vincent
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium.
| | - Daniel De Backer
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
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Abstract
There are unique features of renal oxygenation that render the kidney susceptible to oxygen demand-supply mismatch and hypoxia. Renal oxygen consumption by oxidative metabolism is closely coupled to and driven by tubular transport, which is linked to the filtered solute load and glomerular filtration rate (GFR). In turn, filtered solute load and GFR are dependent on the renal blood flow. Hence, changes in renal blood flow increase oxygen delivery but also increase oxygen demand (consumption) simultaneously by increasing the tubular workload of solute transport. The renal blood flow to different regions of kidney is also inhomogeneous, increasing the oxygen demand-supply mismatch in particular areas such as the outer medulla which become more susceptible to injury. Thus, tubular transport and oxidative metabolism by mi ochondria are closely coupled in the kidney and are the principal determinants of intrarenal oxygenation. Here we review the published literature characterizing renal oxygenation and mitochondrial function in ischemic and sepsis-associated acute kidney injury (AKI). However, the coupling of transport and metabolism in AKI has not been examined. This is a potentially fruitful area of research that should become increasingly active given the emerging data linking renal oxygenation and hypoxia to acute and chronic dysfunction in the kidney.
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Affiliation(s)
- Noureddin Nourbakhsh
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, and VA San Diego Healthcare System, San Diego, Calif., USA
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Smith JA, Stallons LJ, Schnellmann RG. Renal cortical hexokinase and pentose phosphate pathway activation through the EGFR/Akt signaling pathway in endotoxin-induced acute kidney injury. Am J Physiol Renal Physiol 2014; 307:F435-44. [PMID: 24990892 DOI: 10.1152/ajprenal.00271.2014] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
While disruption of energy production is an important contributor to renal injury, metabolic alterations in sepsis-induced AKI remain understudied. We assessed changes in renal cortical glycolytic metabolism in a mouse model of sepsis-induced AKI. A specific and rapid increase in hexokinase (HK) activity (∼2-fold) was observed 3 h after LPS exposure and maintained up to 18 h, in association with a decline in renal function as measured by blood urea nitrogen (BUN). LPS-induced HK activation occurred independently of HK isoform expression or mitochondrial localization. No other changes in glycolytic enzymes were observed. LPS-mediated HK activation was not sufficient to increase glycolytic flux as indicated by reduced or unchanged pyruvate and lactate levels in the renal cortex. LPS-induced HK activation was associated with increased glucose-6-phosphate dehydrogenase activity but not glycogen production. Mechanistically, LPS-induced HK activation was attenuated by pharmacological inhibitors of the EGF receptor (EGFR) and Akt, indicating that EGFR/phosphatidylinositol 3-kinase/Akt signaling is responsible. Our findings reveal LPS rapidly increases renal cortical HK activity in an EGFR- and Akt-dependent manner and that HK activation is linked to increased pentose phosphate pathway activity.
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Affiliation(s)
- Joshua A Smith
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina; and
| | - L Jay Stallons
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina; and
| | - Rick G Schnellmann
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina; and Ralph H. Johnson Veterans Administration Medical Center, Charleston, South Carolina
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May CN, Ishikawa K, Wan L, Williams J, Wellard RM, Pell GS, Jackson GD, Bellomo R. Renal bioenergetics during early gram-negative mammalian sepsis and angiotensin II infusion. Intensive Care Med 2012; 38:886-93. [PMID: 22302028 DOI: 10.1007/s00134-012-2487-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 01/01/2012] [Indexed: 12/17/2022]
Abstract
PURPOSE To measure renal adenosine triphosphate (ATP) (bioenergetics) during hypotensive sepsis with or without angiotensin II (Ang II) infusion. METHODS In anaesthetised sheep implanted with a renal artery flow probe and a magnetic resonance coil around one kidney, we induced hypotensive sepsis with intravenous Escherichia coli injection. We measured mean arterial pressure (MAP), heart rate, renal blood flow RBF and renal ATP levels using magnetic resonance spectroscopy. After 2 h of sepsis, we randomly assigned sheep to receive an infusion of Ang II or vehicle intravenously and studied the effect of treatment on the same variables. RESULTS After E. coli administration, the experimental animals developed hypotensive sepsis (MAP from 92 ± 9 at baseline to 58 ± 4 mmHg at 4 h). Initially, RBF increased, then, after 4 h, it decreased below control levels (from 175 ± 28 at baseline to 138 ± 27 mL/min). Despite decreased RBF and hypotension, renal ATP was unchanged (total ATP to inorganic phosphate ratio from 0.69 ± 0.02 to 0.70 ± 0.02). Ang II infusion restored MAP but caused significant renal vasoconstriction. However, it induced no changes in renal ATP (total ATP to inorganic phosphate ratio from 0.79 ± 0.03 to 0.80 ± 0.02). CONCLUSIONS During early hypotensive experimental gram-negative sepsis, there was no evidence of renal bioenergetic failure despite decreased RBF. In this setting, the addition of a powerful renal vasoconstrictor does not lead to deterioration in renal bioenergetics.
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Affiliation(s)
- Clive N May
- Howard Florey Institute, Florey Neurosciences Institutes, University of Melbourne, Parkville, VIC, Australia.
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Dyson A, Bezemer R, Legrand M, Balestra G, Singer M, Ince C. Microvascular and interstitial oxygen tension in the renal cortex and medulla studied in a 4-h rat model of LPS-induced endotoxemia. Shock 2011; 36:83-9. [PMID: 21368713 DOI: 10.1097/SHK.0b013e3182169d5a] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The pathophysiology of sepsis-induced acute kidney injury remains poorly understood. As changes in renal perfusion and oxygenation have been shown, we aimed to study the short-term effects of endotoxemia on microvascular and interstitial oxygenation in the cortex and medulla, in conjunction with global and renal hemodynamics. In a 4-h rat model of endotoxemia, we simultaneously assessed renal artery blood flow and microvascular and interstitial oxygen tensions in the renal cortex and medulla using ultrasonic flowmetry, dual wavelength phosphorimetry, and tissue oxygen tension monitoring, respectively. Whereas medullary microvascular and interstitial oxygen tensions decreased promptly in line with macrovascular blood flow, changes in cortical oxygenation were only seen later on. During the entire experimental protocol, the gradient between microvascular PO₂ and tissue oxygen tension remained unchanged in both cortex and outer medulla. At study end, urine output was significantly decreased despite a maintained oxygen consumption rate. In this 4-h rat model of endotoxemia, total renal oxygen consumption and the gradient between microvascular PO₂ and tissue oxygen tension remained unaltered, despite falls in renal perfusion and oxygen delivery and urine output. Taken in conjunction with the decrease in urine output, our results could represent either a functional renal impairment or an adaptive response.
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Tran M, Tam D, Bardia A, Bhasin M, Rowe GC, Kher A, Zsengeller ZK, Akhavan-Sharif MR, Khankin EV, Saintgeniez M, David S, Burstein D, Karumanchi SA, Stillman IE, Arany Z, Parikh SM. PGC-1α promotes recovery after acute kidney injury during systemic inflammation in mice. J Clin Invest 2011; 121:4003-14. [PMID: 21881206 DOI: 10.1172/jci58662] [Citation(s) in RCA: 352] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 07/13/2011] [Indexed: 01/16/2023] Open
Abstract
Sepsis-associated acute kidney injury (AKI) is a common and morbid condition that is distinguishable from typical ischemic renal injury by its paucity of tubular cell death. The mechanisms underlying renal dysfunction in individuals with sepsis-associated AKI are therefore less clear. Here we have shown that endotoxemia reduces oxygen delivery to the kidney, without changing tissue oxygen levels, suggesting reduced oxygen consumption by the kidney cells. Tubular mitochondria were swollen, and their function was impaired. Expression profiling showed that oxidative phosphorylation genes were selectively suppressed during sepsis-associated AKI and reactivated when global function was normalized. PPARγ coactivator-1α (PGC-1α), a major regulator of mitochondrial biogenesis and metabolism, not only followed this pattern but was proportionally suppressed with the degree of renal impairment. Furthermore, tubular cells had reduced PGC-1α expression and oxygen consumption in response to TNF-α; however, excess PGC-1α reversed the latter effect. Both global and tubule-specific PGC-1α-knockout mice had normal basal renal function but suffered persistent injury following endotoxemia. Our results demonstrate what we believe to be a novel mechanism for sepsis-associated AKI and suggest that PGC-1α induction may be necessary for recovery from this disorder, identifying a potential new target for future therapeutic studies.
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Affiliation(s)
- Mei Tran
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
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Hsing CH, Chou W, Wang JJ, Chen HW, Yeh CH. Propofol increases bone morphogenetic protein-7 and decreases oxidative stress in sepsis-induced acute kidney injury. Nephrol Dial Transplant 2010; 26:1162-72. [PMID: 20864551 DOI: 10.1093/ndt/gfq572] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Pro-inflammatory cytokines and free radicals damage renal tissue leading to acute kidney injury (AKI) during sepsis. Bone morphogenetic protein-7 (BMP-7) represses tumour necrosis factor (TNF)-α-induced inflammatory responses and protects kidney from injury. The sedative agent, propofol, has immunomodulatory and antioxidative properties. The present study investigated whether propofol could reduce AKI in caecal ligation and puncture (CLP) mice and the possible mechanism behind this. METHODS Mice were treated with propofol or saline immediately and 12 h after CLP surgery. Kidney injury, survival and cytokine expressions of CLP mice were observed 24 h after CLP surgery. In vitro, lipopolysaccharide (LPS)-stimulated rat mesangial cells (RMCs) or hydrogen peroxide (H(2)O(2))-exposed murine kidney epithelial cells (M1) were treated with propofol. The expression of BMP-7, TNF-α and monocyte chemotactic protein (MCP)-1 in CLP mice kidney, RMCs or M1 cells was determined by RT-PCR. Free radical generation and cell death of RMCs and M1 cells were analysed. Nuclear factor (NF)-κB and peroxisome proliferator-activated receptor (PPAR)-γ expressions in LPS-stimulated RMCs were determined by western blotting. RESULTS Propofol increased survival and ameliorated AKI in CLP mice. Propofol increased BMP-7 expression but decreased TNF-α and MCP-1 expressions in the kidney of CLP mice and LPS-stimulated RMCs. Propofol also inhibited free radical generation and cell death in LPS-stimulated RMCs and decreased the TNF-α expression and cell death in H(2)O(2)-exposed M1 cells. Moreover, propofol decreased NF-κB but increased PPAR-γ expression in LPS-stimulated RMCs. CONCLUSIONS Propofol treatment could protect kidney from sepsis-induced AKI by increasing BMP-7 expression, decreasing inflammatory cytokines and inhibiting oxidative stress.
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Affiliation(s)
- Chung-Hsi Hsing
- Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan
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Johannes T, Mik EG, Klingel K, Goedhart PT, Zanke C, Nohé B, Dieterich HJ, Unertl KE, Ince C. EFFECTS OF 1400W AND/OR NITROGLYCERIN ON RENAL OXYGENATION AND KIDNEY FUNCTION DURING ENDOTOXAEMIA IN ANAESTHETIZED RATS. Clin Exp Pharmacol Physiol 2009; 36:870-9. [DOI: 10.1111/j.1440-1681.2009.05204.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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César de Oliveira P, Boer-Lima PA, Figueiredo JF, Gontijo JAR. Effect of Nitric Oxide Synthase Inhibition and Saline Administration on Blood Pressure and Renal Sodium Handling During Experimental Sepsis in Rats. Ren Fail 2009; 25:897-908. [PMID: 14669849 DOI: 10.1081/jdi-120026025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Much effort has been made in recent years to clarify metabolic and renal function changes in sepsis. A number of studies performed in different models of sepsis have been described. One such model that is frequently used is cecal ligation and puncture (CLP) in rats. This model resembles human sepsis in several important aspects, such as an early phase of hyperdynamic, hypermetabolic sepsis followed by a late hypodynamic, hypometabolic phase. The present study evaluated the blood pressure (n = 5) and renal function changes during development of CLP renal failure and to determine the effects of NOS inhibition (L-NAME) and 0.15 M NaCl administration on tail blood pressure and renal function in randomly assigned five groups (n = 10 each): (1) Sham-operated, (2) Sham-operated L-NAME-treated, (3) CLP rats, (4) CLP L-NAME-treated, and (5) CLP 0.15 M NaCl-treated rats. The basal tail blood pressure was not significantly different among the four groups. One week later, arterial pressure was significantly increased in sham-operated L-NAME-treated rats (159 +/- 12 mmHg) compare with the other groups (118 +/- 9.0 mmHg in nontreated rats, p < 0.05). Blood pressure shows a slightly and not significant decrease up to 12h in L-NAME and 0.15 M NaCl treated rats, which in turn was followed by a significant reduced arterial pressure 18h after CLP in both groups (L-NAME: 96.0 +/- 3.6 mmHg, p < 0.05) and NaCl: 82.3 +/- 2.4 mmHg, p < 0.05) compared to sham-operated groups. The glomerular filtration rate estimated by CCr decreases significantly in the CLP untreated group (p < 0.001) and did not significantly differ from the sham-operated and L-NAME-treated groups (p = 0.4) during the studies of renal tubule sodium handling. On the other hand, subcutaneous 0.15 M NaCl administration prevented CCr decreases in CLP rats (p = 0.25). CLP increased the FENa in the sham-operated from: 857.2 +/- 85.1 delta%min(-1) to CLP: 1197.8 +/- 119.0 delta%min(-1). The high FENa to CLP was blunted and significantly reduced by previous systemic treatment of animals with L-NAME from sham-operated+L-NAME: 1368.0 +/- 72.0 delta%min(-1) to CLP+L-NAME: 1148.0 +/- 60.4 delta%min(-1) (p < 0.01). The enhanced FENa in the CLP group were accompanied by a significant increase in proximal sodium reabsorption rejection. The salient findings of the present study suggest that a decrease in the blood pressure and creatinine clearance caused by CLP may benefit from L-NAM and fluid resuscitation during initial bacteremia (first 12 h) by promoting an additional increase of tubule sodium reabsorption in the post-proximal segments of nephrons, but these therapies could not prevent acute renal failure after established endotoxemia.
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Abstract
The pathophysiology of acute renal failure (ARF) in sepsis is only partly understood. In several animal models of septic ARF, no profound tissue hypoxia or decrease in microcirculatory PO2 (microPO2) can be seen. We hypothesized that heterogeneity of microcirculatory oxygen supply to demand in the kidney is obscured when looking at the average microPO2 during endotoxemia. In 20 anesthetized and ventilated rats, MAP, renal blood flow (RBF), and creatinine clearance (CLcrea) were recorded. Renal microPO2 was measured by phosphorescence quenching, allowing measurement of microPO2 distributions. Five animals received a 1-h LPS infusion (10 mg kg h). In 5 rats, RBF was mechanically reduced to 2.1 +/- 0.2 mL min. Five animals served as time control. LPS infusion significantly reduced RBF to 2.1 +/- 0.2 mL min and induced anuria. Average cortical microPO2 decreased from 68 +/- 4 to 52 +/- 6 mmHg, with a significant left shift in the cortical oxygen histogram toward hypoxia. This shift could not be observed in animals receiving mechanical RBF reduction. In these animals, CLcrea was reduced to 50%. An additional group of rats (n = 5) received fluid resuscitation. In these animals, RBF was restored to baseline, CLcrea increased approximately 50%, and the cortical microcirculatory hypoxic areas disappeared after resuscitation. In conclusion, endotoxemia was associated with the occurrence of cortical microcirculatory hypoxic areas that are not detected in the average PO2 measurement, proving the hypothesis of our study. These observations suggest the involvement of hypoxia in the pathogenesis of endotoxemia-induced ARF.
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Yu SY, Song YM, Li AM, Yu XJ, Zhao G, Song MB, Lin CM, Tao CR, Huang L. Isolation and Characterization of Human Coronary Artery-Derived Endothelial Cells in vivo from Patients Undergoing Percutaneous Coronary Interventions. J Vasc Res 2009; 46:487-94. [DOI: 10.1159/000200964] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Accepted: 10/18/2008] [Indexed: 11/19/2022] Open
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Chvojka J, Sykora R, Krouzecky A, Radej J, Varnerova V, Karvunidis T, Hes O, Novak I, Radermacher P, Matejovic M. Renal haemodynamic, microcirculatory, metabolic and histopathological responses to peritonitis-induced septic shock in pigs. Crit Care 2008; 12:R164. [PMID: 19108740 PMCID: PMC2646329 DOI: 10.1186/cc7164] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 11/12/2008] [Accepted: 12/24/2008] [Indexed: 02/06/2023]
Abstract
Introduction Our understanding of septic acute kidney injury (AKI) remains incomplete. A fundamental step is the use of animal models designed to meet the criteria of human sepsis. Therefore, we dynamically assessed renal haemodynamic, microvascular and metabolic responses to, and ultrastructural sequelae of, sepsis in a porcine model of faecal peritonitis-induced progressive hyperdynamic sepsis. Methods In eight anaesthetised and mechanically ventilated pigs, faecal peritonitis was induced by inoculating autologous faeces. Six sham-operated animals served as time-matched controls. Noradrenaline was administered to maintain mean arterial pressure (MAP) greater than or equal to 65 mmHg. Before and at 12, 18 and 22 hours of peritonitis systemic haemodynamics, total renal (ultrasound Doppler) and cortex microvascular (laser Doppler) blood flow, oxygen transport and renal venous pressure, acid base balance and lactate/pyruvate ratios were measured. Postmortem histological analysis of kidney tissue was performed. Results All septic pigs developed hyperdynamic shock with AKI as evidenced by a 30% increase in plasma creatinine levels. Kidney blood flow remained well-preserved and renal vascular resistance did not change either. Renal perfusion pressure significantly decreased in the AKI group as a result of gradually increased renal venous pressure. In parallel with a significant decrease in renal cortex microvascular perfusion, progressive renal venous acidosis and an increase in lactate/pyruvate ratio developed, while renal oxygen consumption remained unchanged. Renal histology revealed only subtle changes without signs of acute tubular necrosis. Conclusion The results of this experimental study argue against the concept of renal vasoconstriction and tubular necrosis as physiological and morphological substrates of early septic AKI. Renal venous congestion might be a hidden and clinically unrecognised contributor to the development of kidney dysfunction.
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Affiliation(s)
- Jiri Chvojka
- Intensive care unit, 1st Medical Department, Charles University Medical School and Teaching Hospital Plzen, alej Svobody 80, Plzen, 304 60, Czech Republic.
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Versteilen AMG, Heemskerk AEJ, Groeneveld ABJ, van Wijhe M, van Lambalgen AA, Tangelder GJ. Mechanisms of the urinary concentration defect and effect of desmopressin during endotoxemia in rats. Shock 2008; 29:217-22. [PMID: 17693923 DOI: 10.1097/shk.0b013e3180ca9e53] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Acute renal failure during human sepsis is often nonoliguric. To study the underlying mechanisms, renal function was assessed in endotoxic and control male Wistar rats during and after saline loading and treatment with the selective V2 receptor agonist desmopressin. Escherichia coli endotoxin (dose, 8 mg/kg) was administered from time (t)=0 to t=60 min; saline loading (rate, 5 mL/100 g per hour) was administered from t=0 to t=120 min. Thereafter, half of each group received desmopressin (dose, 10 microg) for 1 h. The inner medullary (IM) osmolality, hematocrit, plasma, and urinary concentrations of sodium, potassium, urea, and osmolality were measured; then, aquaporin 2 (AQP2) immunohistochemistry was performed. Plasma vasopressin concentrations were measured at t=180 min. Saline loading increased urine volume in all rats. In the endotoxic group, mean arterial pressure decreased when saline loading was stopped. Despite increased hematocrit and vasopressin levels (>16 pg/mL), the endotoxin group had a low IM osmolality (mean +/- SEM, 412+/-0.04 mOsm/kg H2O) in comparison with the control group (mean +/- SEM, 1,094+/-0.17 mOsm/kg H2O) and was not able to either decrease urine volume or raise urine osmolality. Desmopressin treatment in endotoxin-treated rats maintained mean arterial pressure, increased sodium reabsorption, IM osmolality, and urine osmolality, and decreased urine flow. The AQP2 intensity decreased in the endotoxin group, and the apical localization disappeared; both were not affected by desmopressin. Our results indicate that endotoxemia in rats acutely diminishes renal urinary concentration capacity and is associated with a decreased IM osmolality and diminished apical AQP2 localization. These findings may help to explain nonoliguric acute renal failure in human septic shock.
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Affiliation(s)
- Amanda M G Versteilen
- Laboratory for Physiology and Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
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21
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Abstract
OBJECTIVE In experimental septic acute renal failure, urinary analysis is used to help diagnose and classify renal injury. However, the scientific basis for such use has not been systematically evaluated. Thus, we appraised the value of common urinary findings for the diagnosis and classification of experimental septic acute renal failure. DESIGN Systematic review. SETTING Academic medical center and university-based research laboratory. SUBJECTS Experimental studies describing urinary biochemistry, derived indexes, and microscopy in septic acute renal failure. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Twenty-seven articles fulfilled all inclusion criteria. Due to heterogeneity, no formal quantitative analysis was possible. The methods for induction of sepsis and models were variable. The urinary sodium, fractional excretion of sodium, and urine osmolality were reported in only four (15%), 21 (78%), and seven (26%) studies, respectively. The fractional excretion of sodium exhibited a decrease, no change, or an increase from baseline in 11 (52%), five (24%), and five (24%) studies, respectively. The urine osmolality decreased from baseline in all endotoxin-induced models but showed an early transient increase in six (22%) studies of cecal-ligation perforation. Proteinuria or urinary enzymuria was reported in only seven (26%) studies. Urinary microscopy was described in one study. Only ten studies (37%) simultaneously reported on histopathology. In all these studies, histology either was normal or showed minor ultrastructural changes on electron microscopy. CONCLUSIONS No conclusions are possible on how several urinary tests perform in diagnosing or classifying acute renal failure or in predicting the presence of acute tubular necrosis in experimental sepsis. Additional research is necessary to define the diagnostic and prognostic value of urinalysis in experimental sepsis.
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Affiliation(s)
- Sean M Bagshaw
- Division of Critical Care Medicine, University of Alberta Hospital, University of Alberta, Edmonton, AB, Canada.
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Farand P, Hamel M, Lauzier F, Plante GE, Lesur O. Review article: Organ per fusion/permeabilityrelated effects of norepinephrine and vasopressin in sepsis. Can J Anaesth 2006; 53:934-46. [PMID: 16960272 DOI: 10.1007/bf03022837] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
PURPOSE One invariable hallmark of severe sepsis is generalized tissue "malperfusion" and hyperpermeability secondary to microcirculatory/capillary leakage. This review focuses on direct and/or indirect influences of norepinephrine, as a standard of care, and vasopressin, as an alternative vasoactive drug, on organ and tissue perfusion/permeability in severe sepsis. SOURCE English and French language articles and books published between 1966 and 2005 were identified through a computerized Medline search using the terms "sepsis, permeability, norepinephrine and vasopressin". Relevant publications were retrieved and scanned for additional sources. PRINCIPAL FINDINGS There are few randomized clinical trials comparing different vasopressors in sepsis; most available literature consists of clinical reports, animal experiments and occasional reviews. Based on the best current evidence from these sources, we describe the status of major organ perfusion/permeability in sepsis (i.e., the lung, the kidney, the heart, the intestine/gut) in the context of sepsis-induced organ dysfunction/failure. Potential and differential therapeutic effects of the vasopressors norepinephrine and arginine-vasopressin, in the setting of sepsis, are identified. CONCLUSIONS In the treatment of sepsis, arginine-vasopressin exhibits organ-specific heterogeneity in vascular responsiveness, compared to norepinephrine. While norepinephrine is a current standard of care in sepsis, arginine-vasopressin shows promise for the treatment of septic shock.
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Affiliation(s)
- Paul Farand
- Laboratoire de Physiologie Rénale et Vasculaire, Quebec, Canada
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Johannes T, Mik EG, Nohé B, Raat NJH, Unertl KE, Ince C. Influence of fluid resuscitation on renal microvascular PO2 in a normotensive rat model of endotoxemia. Crit Care 2006; 10:R88. [PMID: 16784545 PMCID: PMC1550962 DOI: 10.1186/cc4948] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 04/23/2006] [Accepted: 05/12/2006] [Indexed: 11/26/2022]
Abstract
Introduction Septic renal failure is often seen in the intensive care unit but its pathogenesis is only partly understood. This study, performed in a normotensive rat model of endotoxemia, tests the hypotheses that endotoxemia impairs renal microvascular PO2 (μPO2) and oxygen consumption (VO2,ren), that endotoxemia is associated with a diminished kidney function, that fluid resuscitation can restore μPO2, VO2,ren and kidney function, and that colloids are more effective than crystalloids. Methods Male Wistar rats received a one-hour intravenous infusion of lipopolysaccharide, followed by resuscitation with HES130/0.4 (Voluven®), HES200/0.5 (HES-STERIL® ® 6%) or Ringer's lactate. The renal μPO2 in the cortex and medulla and the renal venous PO2 were measured by a recently published phosphorescence lifetime technique. Results Endotoxemia induced a reduction in renal blood flow and anuria, while the renal μPO2 and VO2,ren remained relatively unchanged. Resuscitation restored renal blood flow, renal oxygen delivery and kidney function to baseline values, and was associated with oxygen redistribution showing different patterns for the different compounds used. HES200/0.5 and Ringer's lactate increased the VO2,ren, in contrast to HES130/0.4. Conclusion The loss of kidney function during endotoxemia could not be explained by an oxygen deficiency. Renal oxygen redistribution could for the first time be demonstrated during fluid resuscitation. HES130/0.4 had no influence on the VO2,ren and restored renal function with the least increase in the amount of renal work.
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Affiliation(s)
- Tanja Johannes
- Department of Physiology, Academic Medical Center, University of Amsterdam, The Netherlands
- Department of Anesthesiology and Critical Care, University Hospital Tuebingen, Germany
| | - Egbert G Mik
- Department of Physiology, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Boris Nohé
- Department of Anesthesiology and Critical Care, University Hospital Tuebingen, Germany
| | - Nicolaas JH Raat
- Department of Physiology, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Klaus E Unertl
- Department of Anesthesiology and Critical Care, University Hospital Tuebingen, Germany
| | - Can Ince
- Department of Physiology, Academic Medical Center, University of Amsterdam, The Netherlands
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Langenberg C, Bellomo R, May CN, Egi M, Wan L, Morgera S. Renal Vascular Resistance in Sepsis. ACTA ACUST UNITED AC 2006; 104:p1-11. [PMID: 16691034 DOI: 10.1159/000093275] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2005] [Accepted: 02/03/2006] [Indexed: 01/19/2023]
Abstract
AIMS To assess changes in renal vascular resistance (RVR) in human and experimental sepsis and to identify determinants of RVR. METHODS We performed a systematic interrogation of two electronic reference libraries using specific search terms. Subjects were animals and patients involved in experimental and human studies of sepsis and septic acute renal failure, in which the RVR was assessed. We obtained all human and experimental articles reporting RVR during sepsis. We assessed the role of various factors that might influence the RVR during sepsis using statistical methods. RESULTS We found no human studies, in which the renal blood flow (and, therefore, the RVR) was measured with suitably accurate direct methods. Of the 137 animal studies identified, 52 reported a decreased RVR, 16 studies reported no change in RVR, and 69 studies reported an increased RVR. Consciousness of animals, duration of measurement, method of induction of sepsis, and fluid administration had no effect on the RVR. On the other hand, on univariate analysis, size of the animals (p < 0.001), technique of measurement (p = 0.017), recovery after surgery (p = 0.004), and cardiac output (p < 0.001) influenced the RVR. Multivariate analysis, however, showed that only cardiac output (p = 0.028) and size of the animals (p = 0.031) remained independent determinants of the RVR. CONCLUSIONS Changes in RVR during sepsis in humans are unknown. In experimental sepsis, several factors not directly related to sepsis per se appear to influence the RVR. A high cardiac output and the use of large animals predict a decreased RVR, while a decreased cardiac output and the use of small animals predict an increased RVR.
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Affiliation(s)
- Christoph Langenberg
- Departments of Intensive Care and Medicine, Austin Hospital and University of Melbourne, Heidelberg, Melbourne, Australia
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Langenberg C, Bellomo R, May C, Wan L, Egi M, Morgera S. Renal blood flow in sepsis. Crit Care 2005; 9:R363-74. [PMID: 16137349 PMCID: PMC1269441 DOI: 10.1186/cc3540] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 04/01/2005] [Accepted: 04/14/2005] [Indexed: 02/12/2023]
Abstract
Introduction To assess changes in renal blood flow (RBF) in human and experimental sepsis, and to identify determinants of RBF. Method Using specific search terms we systematically interrogated two electronic reference libraries to identify experimental and human studies of sepsis and septic acute renal failure in which RBF was measured. In the retrieved studies, we assessed the influence of various factors on RBF during sepsis using statistical methods. Results We found no human studies in which RBF was measured with suitably accurate direct methods. Where it was measured in humans with sepsis, however, RBF was increased compared with normal. Of the 159 animal studies identified, 99 reported decreased RBF and 60 reported unchanged or increased RBF. The size of animal, technique of measurement, duration of measurement, method of induction of sepsis, and fluid administration had no effect on RBF. In contrast, on univariate analysis, state of consciousness of animals (P = 0.005), recovery after surgery (P < 0.001), haemodynamic pattern (hypodynamic or hyperdynamic state; P < 0.001) and cardiac output (P < 0.001) influenced RBF. However, multivariate analysis showed that only cardiac output remained an independent determinant of RBF (P < 0.001). Conclusion The impact of sepsis on RBF in humans is unknown. In experimental sepsis, RBF was reported to be decreased in two-thirds of studies (62 %) and unchanged or increased in one-third (38%). On univariate analysis, several factors not directly related to sepsis appear to influence RBF. However, multivariate analysis suggests that cardiac output has a dominant effect on RBF during sepsis, such that, in the presence of a decreased cardiac output, RBF is typically decreased, whereas in the presence of a preserved or increased cardiac output RBF is typically maintained or increased.
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Affiliation(s)
- Christoph Langenberg
- Research fellow, Department of Intensive Care and Department of Medicine, Austin Hospital, and University of Melbourne, Heidelberg, Melbourne, Australia
| | - Rinaldo Bellomo
- Director of Intensive Care Research, Department of Intensive Care and Department of Medicine, Austin Hospital, and University of Melbourne, Heidelberg, Melbourne, Australia
| | - Clive May
- Senior Researcher, Howard Florey Institute, University of Melbourne, Parkville, Melbourne, Australia
| | - Li Wan
- Research fellow, Department of Intensive Care and Department of Medicine, Austin Hospital, and University of Melbourne, Heidelberg, Melbourne, Australia
| | - Moritoki Egi
- Research fellow, Department of Intensive Care and Department of Medicine, Austin Hospital, and University of Melbourne, Heidelberg, Melbourne, Australia
| | - Stanislao Morgera
- Consultant Nephrologist, Department of Nephrology, Charité Campus Mitte, Berlin, Germany
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Nijveldt RJ, Siroen MPC, Teerlink T, van Lambalgen AA, Rauwerda JA, van Leeuwen PAM. Gut and liver handling of asymmetric and symmetric dimethylarginine in the rat under basal conditions and during endotoxemia. Liver Int 2004; 24:510-8. [PMID: 15482350 DOI: 10.1111/j.1478-3231.2004.0948.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
INTRODUCTION/AIM Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase enzymes, whereas symmetric dimethylarginine (SDMA) competes with arginine transport. Although both dimethylarginines may be important regulators of the arginine-NO pathway, their metabolism is largely unknown. In previous studies, evidence was found for the liver in the metabolism of dimethylarginines. We aimed to investigate dimethylarginine handling of the gut and the liver in detail under basal conditions and during endotoxemia. METHODS Twenty-one male Wistar rats were used for this study. Endotoxemia was induced by lipopolysaccharide (LPS) infusion (8 mg/kg). Blood flow was measured using radiolabeled microspheres according to the reference sample method. Concentration of dimethylarginines were measured by high-performance liquid chromatography. The combination of arteriovenous concentration difference and organ blood flow allowed calculation of net organ fluxes and fractional extraction (FE) rates. RESULTS Arterial plasma concentration of ADMA was lower in LPS rats, in contrast to a higher SDMA concentration. For the gut, net release of ADMA was found, which was higher in LPS rats. In contrast, for the gut, net uptake of SDMA was found, which was lower in LPS rats. For the liver, a high net uptake of ADMA was found in both groups, while FE was significantly increased in LPS rats. Hepatic handling of SDMA was negligible. CONCLUSION The liver plays an important role in eliminating ADMA from the circulation and endotoxemia stimulates this capacity. In contrast to the liver, the gut releases ADMA. Endotoxemia results in a reduced systemic ADMA concentration.
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Affiliation(s)
- Robert J Nijveldt
- Department of Surgery, VU University Medical Center, 1007 MB Amsterdam, the Netherlands
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van Dam B, Demirci C, Reitsma HJ, van Lambalgen AA, van den Bos GC, Tangelder GJ, Stehouwer CDA. Arteriolar changes in nitric oxide activity and sensitivity during the course of streptozotocin-induced diabetes. Eur J Pharmacol 2002; 455:43-51. [PMID: 12433593 DOI: 10.1016/s0014-2999(02)02501-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitric oxide (NO) may play an important role in the pathogenesis of diabetic microangiopathy. However, arteriolar changes in NO activity and sensitivity to NO may be dependent on both the type of arteriole and the duration of diabetes. Therefore, we assessed, in the in situ spinotrapezius muscle preparation of streptozotocin-diabetic rats and of controls, inside diameters of A2-A4 arterioles and the reactivity to topically applied acetylcholine and nitroprusside, before and after N(G)-nitro-L-arginine (L-NNA) at 2, 4, 6 and 12 weeks of diabetes. In A2 arterioles, basal diameters and the contribution of NO to basal diameter were not affected during the course of streptozotocin-induced diabetes. However, the maximal response to acetylcholine in these arterioles was attenuated after 2 until 4 weeks, and from 4 weeks on a sustained decrease in reactivity to sodium nitroprusside was observed. In A3 arterioles, both the basal diameter and the contribution of NO to basal diameter were decreased after 2 weeks and increased after 6 weeks, while the response to sodium nitroprusside was unaffected. In A4 arterioles, a significant increase in basal diameter was observed after 6 weeks only. Thus, this study shows that streptozotocin-induced diabetes causes microvascular changes in NO activity and sensitivity that depend on the type of arteriole. For each order of arteriole, these changes show a specific pattern during the course of diabetes.
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Affiliation(s)
- Bastiaan van Dam
- Department of Internal Medicine, Institute for Cardiovascular Research, Vrije Universiteit, P.O. Box 7057, De Boelelaan, 1117, 1081 HV Amsterdam, The Netherlands
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