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Abstract
Amiloride is a potassium retaining diuretic and natriuretic which acts by reversibly
blocking luminal epithelial sodium channels (ENaCs) in the late distal tubule and
collecting duct. Amiloride is indicated in oedematous states, and for potassium
conservation adjunctive to thiazide or loop diuretics for hypertension, congestive heart
failure and hepatic cirrhosis with ascites. Historical studies on its use in hypertension
were poorly controlled and there is insufficient data on dose-response. It is clearly
highly effective in combination with thiazide diuretics where it counteracts the adverse
metabolic effects of the thiazides and its use in the Medical Research Council Trial of
Older Hypertensive Patients, demonstrated convincing outcome benefits on stroke and
coronary events. Recently it has been shown to be as effective as spironolactone in
resistant hypertension but there is a real need to establish its potential role in the
much larger number of patients with mild to moderate hypertension in whom there is a
paucity of information with amiloride particularly across an extended dose range.
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Affiliation(s)
- Qianhui Sun
- Imperial College London, Faculty of Medicine, Faculty Building, Level 2, London, UK
| | - Peter Sever
- Imperial College London, National Heart and Lung Institute, ICTEM Building, Level 3, London, UK
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A Comparison of Urine Dilution Ability between Adult Dominant Polycystic Kidney Disease, Other Chronic Kidney Diseases, and Healthy Control Subjects: A Case-Control Study. Int J Nephrol 2020; 2020:4108418. [PMID: 33343937 PMCID: PMC7728487 DOI: 10.1155/2020/4108418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/10/2020] [Accepted: 11/19/2020] [Indexed: 11/28/2022] Open
Abstract
The final dilution of urine is regulated via aquaporin-2 water channels in the distal part of the nephron. It is unclear whether urine dilution ability in autosomal dominant polycystic kidney disease patients (ADPKD patients) differs from other patients with similar degree of impaired renal function (non-ADPKD patients). The purpose of this case control study was to measure urine dilution ability in ADPKD patients compared to non-ADPKD patients and healthy controls. Methods. Eighteen ADPKD, 16 non-ADPKD patients (both with chronic kidney disease, stage I-IV), and 18 healthy controls received an oral water load of 20 ml/kg body weight. Urine was collected in 7 consecutive periods. We measured free water clearance (CH2O), urine osmolality, urine output, fractional excretion of sodium, urine aquaporin2 (u-AQP2), and urine epithelial sodium channel (u-ENaC). Blood samples were drawn four times (at baseline, 2 h, 4 h, and 6 hours after the water load) for analyses of plasma osmolality, vasopressin, renin, angiotensin II, and aldosterone. Brachial and central blood pressure was measured regularly during the test. Results. The three groups were age and gender matched, and the patient groups had similar renal function. One hour after water load, the ADPKD patients had an increased CH2O compared to non-ADPKD patients (2.97 ± 2.42 ml/min in ADPKD patients vs. 1.31 ± 1.50 ml/min in non-ADPKD patients, p0.029). The reduction in u-AQP2 and u-ENaC occurred earlier in ADPKD than in non-ADPKD patients. Plasma concentrations of vasopressin, renin, angiotensin II, and aldosterone and blood pressure measurements did not show any differences that could explain the deviation in urine dilution capacity between the patient groups. Conclusions. ADPKD patients had a higher CH2O than non-ADPKD patients after an oral water load, and u-AQP2 and u-ENaC were more rapidly reduced than in non-ADPKD patients. Thus, urine-diluting capacity may be better preserved in ADPKD patients than in non-ADPKD patients.
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Urine concentration ability is reduced to the same degree in adult dominant polycystic kidney disease compared with other chronic kidney diseases in the same CKD-stage and lower THAN in healthy control subjects - a CASE control study. BMC Nephrol 2020; 21:379. [PMID: 32867720 PMCID: PMC7457520 DOI: 10.1186/s12882-020-02043-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/23/2020] [Indexed: 01/20/2023] Open
Abstract
Background Concentration of the urine is primarily regulated via vasopressin dependent aquaporin-2 water channels in the apical membrane of kidney principal cells. It is unclear whether urine concentration ability in ADPKD differs from other patients with similar degree of impaired renal function (non-ADPKD patients). The purpose of this case control study was to measure urine concentration ability in ADPKD patients compared to non-ADPKD patients and healthy controls. Methods A seventeen hour long water deprivation test was carried out in 17 ADPKD patients (CKD I-IV), 16 non-ADPKD patients (CKD I-IV), and 18 healthy controls. Urine was collected in 4 consecutive periods during water deprivation (12 h, 1 h, 2 h and 2 h, respectively) and analyzed for osmolality (u-Osm), output (UO), fractional excretion of sodium (FENa), aquaporin2 (u-AQP2) and ENaC (u-ENaC). Blood samples were drawn trice (after 13-, 15-, and 17 h after water deprivation) for analyses of osmolality (p-Osm), vasopressin (p-AVP), and aldosterone (p-Aldo). Results U-Osm was significantly lower and FENa significantly higher in both ADPKD patients and non-ADPKD patients compared to healthy controls during the last three periods of water deprivation. During the same periods, UO was higher and secretion rates of u-AQP2 and u-ENaC were lower and at the same level in the two groups of patients compared to controls. P-AVP and p-Osm did not differ significantly between the three groups. P-Aldo was higher in both groups of patients than in controls. Conclusions Urine concentration ability was reduced to the same extent in patients with ADPKD and other chronic kidney diseases with the same level of renal function compared to healthy controls. The lower urine excretion of AQP2 and ENaC suggests that the underlying mechanism may be a reduced tubular response to vasopressin and aldosterone. Trial registration Current Controlled Trial NCT04363554, date of registration: 20.08.2017.
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Al Therwani S, Malmberg MES, Rosenbaek JB, Bech JN, Pedersen EB. Effect of tolvaptan on renal handling of water and sodium, GFR and central hemodynamics in autosomal dominant polycystic kidney disease during inhibition of the nitric oxide system: a randomized, placebo-controlled, double blind, crossover study. BMC Nephrol 2017; 18:268. [PMID: 28810844 PMCID: PMC5558668 DOI: 10.1186/s12882-017-0686-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/07/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Tolvaptan slows progression of autosomal dominant polycystic kidney disease (ADPKD) by antagonizing the vasopressin-cAMP axis. Nitric oxide (NO) stimulates natriuresis and diuresis, but its role is unknown during tolvaptan treatment in ADPKD. METHODS Eighteen patients with ADPKD received tolvaptan 60 mg or placebo in a randomized, placebo-controlled, double blind, crossover study. L-NMMA (L-NG-monomethyl-arginine) was given as a bolus followed by continuous infusion during 60 min. We measured: GFR, urine output (UO), free water clearance (CH2O), fractional excretion of sodium (FENa), urinary excretion of aquaporin-2 channels (u-AQP2) and epithelial sodium channels (u-ENaCγ), plasma concentrations of vasopressin (p-AVP), renin (PRC), angiotensinII (p-AngII), aldosterone (p-Aldo), and central blood pressure (cBP). RESULTS During tolvaptan with NO-inhibition, a more pronounced decrease was measured in UO, CH2O (61% vs 43%) and FENa (46% vs 41%) after placebo than after tolvaptan; GFR and u-AQP2 decreased to the same extent; p-AVP increased three fold, whereas u-ENaCγ, PRC, p-AngII, and p-Aldo remained unchanged. After NO-inhibition, GFR increased after placebo and remained unchanged after tolvaptan (5% vs -6%). Central diastolic BP (CDBP) increased to a higher level after placebo than tolvaptan. Body weight fell during tolvaptan treatment. CONCLUSIONS During NO inhibition, tolvaptan antagonized both the antidiuretic and the antinatriuretic effect of L-NMMA, partly via an AVP-dependent mechanism. U-AQP2 was not changed by tolvaptan, presumeably due to a counteracting effect of elevated p-AVP. The reduced GFR during tolvaptan most likely is caused by the reduction in extracellular fluid volume and blood pressure. TRIAL REGISTRATION Clinical Trial no: NCT02527863 . Registered 18 February 2015.
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Affiliation(s)
- Safa Al Therwani
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital and Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark.
| | - My Emma Sofie Malmberg
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital and Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
| | - Jeppe Bakkestroem Rosenbaek
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital and Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
| | - Jesper Noergaard Bech
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital and Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
| | - Erling Bjerregaard Pedersen
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital and Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
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Rosenbaek JB, Al Therwani S, Jensen JM, Mose FH, Wandall-Frostholm C, Pedersen EB, Bech JN. Effect of sodium nitrite on renal function and sodium and water excretion and brachial and central blood pressure in healthy subjects: a dose-response study. Am J Physiol Renal Physiol 2017; 313:F378-F387. [PMID: 28490529 DOI: 10.1152/ajprenal.00400.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 04/21/2017] [Accepted: 05/02/2017] [Indexed: 01/12/2023] Open
Abstract
Sodium nitrite (NaNO2) is converted to nitric oxide (NO) in vivo and has vasodilatory and natriuretic effects. Our aim was to examine the effects of NaNO2 on hemodynamics, sodium excretion, and glomerular filtration rate (GFR). In a single-blinded, placebo-controlled, crossover study, we infused placebo (0.9% NaCl) or 0.58, 1.74, or 3.48 μmol NaNO2·kg-1·h-1 for 2 h in 12 healthy subjects, after 4 days of a standard diet. Subjects were supine and water loaded. We measured brachial and central blood pressure (BP), plasma concentrations of renin, angiotensin II, aldosterone, arginine vasopressin (P-AVP), and plasma nitrite (P-[Formula: see text]), GFR by Cr-EDTA clearance, fractional excretion of sodium (FENa) free water clearance (CH2O), and urinary excretion rate of guanosine 3',5'-cyclic monophosphate (U-cGMP). The highest dose reduced brachial systolic BP (5.6 mmHg, P = 0.003), central systolic BP (5.6 mmHg, P = 0.035), and CH2O (maximum change from 3.79 to 1.27 ml/min, P = 0.031) and increased P-[Formula: see text] (from 0.065 to 0.766 μmol/l, P < 0.001), while reducing U-cGMP (from 444 to 247 pmol/min, P = 0.004). GFR, FENa, P-AVP, and the components in the renin-angiotensin-aldosterone system did not change significantly. In conclusion, intravenous NaNO2 induced a dose-dependent reduction of brachial and central BP. The hemodynamic effect was not mediated by the renin-angiotensin-aldosterone system. NaNO2 infusion resulted in a vasopressin-independent decrease in CH2O and urine output but no change in urinary sodium excretion or GFR. The lack of increase in cGMP accompanying the increase in [Formula: see text] suggests a direct effect of nitrite or nitrate on the renal tubules and vascular bed with little or no systemic conversion to NO.
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Affiliation(s)
- Jeppe Bakkestroem Rosenbaek
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Aarhus, Denmark; and
| | - Safa Al Therwani
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Aarhus, Denmark; and
| | - Janni Majgaard Jensen
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Aarhus, Denmark; and
| | - Frank Holden Mose
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Aarhus, Denmark; and
| | | | - Erling Bjerregaard Pedersen
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Aarhus, Denmark; and
| | - Jesper Noergaard Bech
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Aarhus, Denmark; and
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Al Therwani S, Rosenbæk JB, Mose FH, Bech JN, Pedersen EB. Effect of tolvaptan on renal water and sodium excretion and blood pressure during nitric oxide inhibition: a dose-response study in healthy subjects. BMC Nephrol 2017; 18:86. [PMID: 28288570 PMCID: PMC5347830 DOI: 10.1186/s12882-017-0501-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/07/2017] [Indexed: 01/17/2023] Open
Abstract
Background Tolvaptan is a selective vasopressin receptor antagonist. Nitric Oxide (NO) promotes renal water and sodium excretion, but the effect is unknown in the nephron’s principal cells. In a dose-response study, we measured the effect of tolvaptan on renal handling of water and sodium and systemic hemodynamics, during baseline and NO-inhibition with L-NMMA (L-NG-monomethyl-arginine). Methods In a randomized, placebo-controlled, double blind, cross over study, 15 healthy subjects received tolvaptan 15, 30 and 45 mg or placebo. L-NMMA was given as a bolus followed by continuous infusion during 60 min. We measured urine output (UO), free water clearance (CH2O), fractional excretion of sodium (FENa), urinary aquaporin-2 channels (u-AQP2) and epithelial sodium channels (u-ENaCγ), plasma vasopressin (p-AVP) and central blood pressure (cBP). Results During baseline, FENa was unchanged. Tolvaptan decreased u-ENaCγ dose-dependently and increased p-AVP threefold, whereas u-AQP2 was unchanged. During tolvaptan with NO-inhibition, UO and CH2O decreased dose-dependently. FENa decreased dose-independently and u-ENaCγ remained unchanged. Central BP increased equally after all treatments. Conclusions During baseline, fractional excretion of sodium was unchanged. During tolvaptan with NO-inhibition, renal water excretion was reduced dose dependently, and renal sodium excretion was reduced unrelated to the dose, partly via an AVP dependent mechanism. Thus, tolvaptan antagonized the reduction in renal water and sodium excretion during NO-inhibition. Most likely, the lack of decrease in AQP2 excretion by tolvaptan could be attributed to a counteracting effect of the high level of p-AVP. Trial registration Clinical Trial no: NCT02078973. Registered 1 March 2014. Electronic supplementary material The online version of this article (doi:10.1186/s12882-017-0501-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Safa Al Therwani
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital, Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark.
| | - Jeppe Bakkestrøm Rosenbæk
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital, Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
| | - Frank Holden Mose
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital, Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
| | - Jesper Nørgaard Bech
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital, Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
| | - Erling Bjerregaard Pedersen
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital, Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500, Holstebro, Denmark
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Breum Jakobsen NF, Laugesen E, Rolighed L, Nissen PH, Poulsen PL, Pedersen EB, Mosekilde L, Rejnmark L. The cardiovascular system in familial hypocalciuric hypercalcemia: a cross-sectional study on physiological effects of inactivating variants in the calcium-sensing receptor gene. Eur J Endocrinol 2016; 175:299-309. [PMID: 27418061 DOI: 10.1530/eje-16-0369] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/14/2016] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Loss-of-function variants in the gene encoding the calcium-sensing receptor (CASR) result in familial hypocalciuric hypercalcemia (FHH), causing hypercalcemia with high normal or elevated parathyroid hormone levels. The CASR may also influence electrolyte and water homeostasis. It is unknown whether FHH affects cardiovascular health. We, therefore investigated whether FHH is associated with changes in the regulation of the cardiovascular system by measuring 24-h blood pressure (BP), arterial stiffness and vasoactive hormones. DESIGN Cross-sectional study comparing 50 patients with FHH to age- and gender-matched controls. RESULTS Studied subjects (69% women) had a mean age of 56years. A similar number of patients and controls (33%) were on treatment with antihypertensive drugs. Overall, no differences were found between groups in 24-h ambulatory BP or pulse wave velocity. However, compared with controls, diastolic BP during nighttime was lower in FHH females (60±5 vs 66±9mmHg, P<0.01) and higher in FHH males (69±6 vs 64±5mmHg, P=0.02). FHH was associated with a significantly higher plasma osmolality (P<0.01), higher plasma levels of vasopressin (P<0.01) and a higher renal excretion of epithelial sodium channels (ENaCs) (P=0.03), whereas urine aquaporin-2 and plasma sodium, aldosterone and renin did not differ between groups. FHH patients had a lower urinary volume with an increased osmolality if analyses were restricted to those not on treatments with antihypertensive drugs. CONCLUSIONS FHH does not seem to be associated with an increased risk of CVD.
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Affiliation(s)
| | - Esben Laugesen
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark Danish Diabetes AcademyOdense University Hospital, Odense, Denmark Department of Clinical MedicineAarhus University, Aarhus, Denmark
| | | | - Peter H Nissen
- Clinical BiochemistryAarhus University Hospital, Aarhus, Denmark
| | - Per Løgstrup Poulsen
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark
| | - Erling Bjerregaard Pedersen
- Department of Clinical MedicineAarhus University, Aarhus, Denmark University Clinic in Nephrology and HypertensionHolstebro Hospital, Hospital Jutland West, Holstebro, Denmark
| | - Leif Mosekilde
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark
| | - Lars Rejnmark
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark Department of Clinical MedicineAarhus University, Aarhus, Denmark
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Huang X, Dorhout Mees E, Vos P, Hamza S, Braam B. Everything we always wanted to know about furosemide but were afraid to ask. Am J Physiol Renal Physiol 2016; 310:F958-71. [PMID: 26911852 DOI: 10.1152/ajprenal.00476.2015] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 02/23/2016] [Indexed: 12/22/2022] Open
Abstract
Furosemide is a widely used, potent natriuretic drug, which inhibits the Na(+)-K(+)-2Cl(-) cotransporter (NKCC)-2 in the ascending limb of the loop of Henle applied to reduce extracellular fluid volume expansion in heart and kidney disease. Undesirable consequences of furosemide, such as worsening of kidney function and unpredictable effects on sodium balance, led to this critical evaluation of how inhibition of NKCC affects renal and cardiovascular physiology. This evaluation reveals important knowledge gaps, involving furosemide as a drug, the function of NKCC2 (and NKCC1), and renal and systemic indirect effects of NKCC inhibition. Regarding renal effects, renal blood flow and glomerular filtration rate could become compromised by activation of tubuloglomerular feedback or by renin release, particularly if renal function is already compromised. Modulation of the intrarenal renin angiotensin system, however, is ill-defined. Regarding systemic effects, vasodilation followed by nonspecific NKCC inhibition and changes in venous compliance are not well understood. Repetitive administration of furosemide induces short-term (braking phenomenon, acute diuretic resistance) and long-term (chronic diuretic resistance) adaptations, of which the mechanisms are not well known. Modulation of NKCC2 expression and activity in kidney and heart failure is ill-defined. Lastly, furosemide's effects on cutaneous sodium stores and on uric acid levels could be beneficial or detrimental. Concluding, a considerable knowledge gap is identified regarding a potent drug with a relatively specific renal target, NKCC2, and renal and systemic actions. Resolving these questions would increase the understanding of NKCCs and their actions and improve rational use of furosemide in pathophysiology of fluid volume expansion.
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Affiliation(s)
- Xiaohua Huang
- Department of Medicine, Division of Nephrology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Evert Dorhout Mees
- Department of Medicine/Nephrology, Utrecht University, Vorden, The Netherlands
| | - Pieter Vos
- Dianet Dialysis Centers, Utrecht, The Netherlands; and
| | - Shereen Hamza
- Department of Medicine, Division of Nephrology and Immunology, University of Alberta, Edmonton, Alberta, Canada; Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
| | - Branko Braam
- Department of Medicine, Division of Nephrology and Immunology, University of Alberta, Edmonton, Alberta, Canada; Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
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Mose FH, Larsen T, Jensen JM, Hansen AB, Bech JN, Pedersen EB. Effects of atorvastatin on systemic and renal NO dependency in patients with non-diabetic stage II-III chronic kidney disease. Br J Clin Pharmacol 2015; 78:789-99. [PMID: 24697877 DOI: 10.1111/bcp.12390] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/25/2014] [Indexed: 12/20/2022] Open
Abstract
AIMS Clinical trials suggest that statins have beneficial effects on the cardiovascular system independent from their cholesterol lowering properties. In patients with chronic kidney disease stage II-III, we tested the hypothesis that atorvastatin increased systemic and renal nitric oxide (NO) availability using L-N(G) -monomethyl arginine (L-NMMA) as an inhibitor of NO production. METHODS In a randomized, placebo-controlled, crossover study patients were treated with atorvastatin for 5 days with standardized diet and fluid intake. Glomerular filtration reate (GFR), fractional excretions of sodium (FENa ), urinary excretion of aquaporin-2 (u-AQP2) and epithelial sodium channels (u-ENaCγ ), vasoactive hormones (renin, angiotensin II, aldosterone, arginine vasopressin, endothelin-1 and brain natriuretic peptide) and central blood pressure (BP) estimated by applanation tonometry were measured before and after systemic administration of the NO inhibitor L-NMMA. RESULTS Atorvastatin caused a significant reduction in U-ENaCγ , but sodium excretion, C H 2 O , FENa and u-AQP2 were not changed by atorvastatin. L-NMMA reduced renal effect variables, including GFR, FENa and u-ENaCγ and increased brachial BP and central BP to a similar extent during both treatments. Vasoactive hormones were changed in the same way by L-NMMA during atorvastatin and placebo treatment. CONCLUSION During, atorvastatin and placebo treatment, inhibition of nitric oxide synthesis induced the same response in brachial and central blood pressure, GFR, renal tubular function and vasoactive hormones. Thus, the data do not support that atorvastatin changes nitric oxide availability in patients with mild nephropathy. The reduced u-ENaC may reflect changes in sodium absorption in the nephron induced by atorvastatin.
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Affiliation(s)
- Frank Holden Mose
- Department of Medical Research, University Clinic in Hypertension and Nephrology, Holstebro Hospital, Holstebro, Denmark
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Mose FH, Jensen JM, Therwani S, Mortensen J, Hansen AB, Bech JN, Pedersen EB. Effect of nebivolol on renal nitric oxide availability and tubular function in patients with essential hypertension. Br J Clin Pharmacol 2015; 80:425-35. [PMID: 25778445 DOI: 10.1111/bcp.12627] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 03/02/2015] [Accepted: 03/04/2015] [Indexed: 12/18/2022] Open
Abstract
AIMS Nebivolol is a selective β1 -receptor antagonist with vasodilating properties. In patients with essential hypertension, we tested the hypothesis that nebivolol increases systemic and renal nitric oxide (NO) availability using L-N(G) -monomethyl arginine (L-NMMA) as an inhibitor of NO production. METHODS In a randomized, placebo-controlled, crossover study, patients with essential hypertension were treated with nebivolol for five days, along with a standardized diet and fluid intake. We examined the acute effects of systemic NO synthase inhibition with L-NMMA on brachial blood pressure (bBP), pulse wave velocity (PWV) and central blood pressure (cBP) estimated by applanation tonometry, glomerular filtration rate (GFR), fractional excretion of sodium (FENa ), urinary excretion of both aquaporin-2 (u-AQP2) and epithelial sodium channels (u-ENaCγ ), and plasma concentrations of nitrate/nitrite (p-NOx ) and vasoactive hormones after five days' treatment with placebo and nebivolol. RESULTS Nebivolol significantly reduced PWV, bBP, cBP and plasma renin, angiotensin II and aldosterone concentrations. The renal parameters, p-NOx and plasma arginine vasopressin concentration were not changed by nebivolol. There was no difference between nebivolol and placebo in the response to L-NMMA, with LMMA inducing a similar increase in PWV, bBP and cBP and a similar decrease in GFR, uAQP2 and u-ENaCγ and FENa [mean change -0.62% (95% confidence interval {CI} -0.40 to -0.84) during placebo vs. -0.57% (95% CI -0.46 to -0.68; P = 0.564) during nebivolol treatment]. Vasoactive hormones were changed to a similar extend by L-NMMA during administration of nebivolol and placebo. CONCLUSIONS Nebivolol did not change p-NOx , and inhibition of NO synthesis induced the same response in blood pressure, GFR, renal tubular function and vasoactive hormones during nebivolol and placebo. Thus, the data did not support the hypothesis that nebivolol changes vascular and renal NO availability in patients with essential hypertension.
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Affiliation(s)
- Frank H Mose
- University Clinic in Nephrology and Hypertension, Department of Medical Research and University of Aarhus
| | - Janni M Jensen
- University Clinic in Nephrology and Hypertension, Department of Medical Research and University of Aarhus
| | - Safa Therwani
- University Clinic in Nephrology and Hypertension, Department of Medical Research and University of Aarhus
| | | | | | - Jesper N Bech
- University Clinic in Nephrology and Hypertension, Department of Medical Research and University of Aarhus
| | - Erling B Pedersen
- University Clinic in Nephrology and Hypertension, Department of Medical Research and University of Aarhus
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Al Therwani S, Mose FH, Jensen JM, Bech JN, Pedersen EB. Effect of vasopressin antagonism on renal handling of sodium and water and central and brachial blood pressure during inhibition of the nitric oxide system in healthy subjects. BMC Nephrol 2014; 15:100. [PMID: 24965902 PMCID: PMC4079642 DOI: 10.1186/1471-2369-15-100] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 06/19/2014] [Indexed: 11/10/2022] Open
Abstract
Background Tolvaptan is a selective vasopressin receptor antagonist (V2R) that increases free water excretion. We wanted to test the hypotheses that tolvaptan changes both renal handling of water and sodium and systemic hemodynamics during basal conditions and during nitric oxide (NO)-inhibition with L-NG-monomethyl-arginine (L-NMMA). Methods Nineteen healthy subjects were enrolled in a randomized, placebo-controlled, double-blind, crossover study of two examination days. Tolvaptan 15 mg or placebo was given in the morning. L-NMMA was given as a bolus followed by continuous infusion during 60 minutes. We measured urine output(UO), free water clearance (CH2O), fractional excretion of sodium (FENa), urinary aquaporin-2 channels (u-AQP2) and epithelial sodium channels (u-ENaCγ), plasma vasopressin (p-AVP), central and brachial blood pressure(cBP, bBP). Results During baseline conditions, tolvaptan caused a significant increase in UO, CH2O and p-AVP, and FENa was unchanged. During L-NMMA infusion, UO and CH2O decreased more pronounced after tolvaptan than after placebo (-54 vs.-42% and -34 vs.-9% respectively). U-AQP2 decreased during both treatments, whereas u-ENaCγ decreased after placebo and increased after tolvaptan. CBP and bBP were unchanged. Conclusion During baseline conditions, tolvaptan increased renal water excretion. During NO-inhibition, the more pronounced reduction in renal water excretion after tolvaptan indicates that NO promotes water excretion in the principal cells, at least partly, via an AVP-dependent mechanism. The lack of decrease in u-AQP2 by tolvaptan could be explained by a counteracting effect of increased plasma vasopressin. The antagonizing effect of NO-inhibition on u-ENaC suggests that NO interferes with the transport via ENaC by an AVP-dependent mechanism.
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Affiliation(s)
- Safa Al Therwani
- University Clinic in Nephrology and Hypertension, Department of Medical Research, Holstebro Hospital and Aarhus University, Hospital Unit Jutland West, Laegaardvej 12, 7500 Holstebro, Denmark.
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Mose FH, Larsen T, Jensen JM, Hansen AB, Bech JN, Pedersen EB. Effect of atorvastatin on renal NO availability and tubular function in patients with stage II-III chronic kidney disease and type 2 diabetes. Scandinavian Journal of Clinical and Laboratory Investigation 2013; 74:8-19. [DOI: 10.3109/00365513.2013.855942] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Larsen T, Mose FH, Bech JN, Pedersen EB. Effect of paricalcitol on renin and albuminuria in non-diabetic stage III-IV chronic kidney disease: a randomized placebo-controlled trial. BMC Nephrol 2013; 14:163. [PMID: 23889806 PMCID: PMC3729723 DOI: 10.1186/1471-2369-14-163] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 07/19/2013] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Vitamin D receptor activators reduce albuminuria, and may improve survival in chronic kidney disease (CKD). Animal studies suggest that these pleiotropic effects of vitamin D may be mediated by suppression of renin. However, randomized trials in humans have yet to establish this relationship. METHODS In a randomized, placebo-controlled, double-blinded crossover study, the effect of oral paricalcitol (2 μg/day) was investigated in 26 patients with non-diabetic, albuminuric stage III-IV CKD. After treatment, plasma concentrations of renin (PRC), angiotensin II (AngII) and aldosterone (Aldo) were measured. GFR was determined by 51Cr-EDTA clearance. Assessment of renal NO dependency was performed by infusion of NG-monomethyl-L-arginine (L-NMMA). Albumin excretion rate (AER) was analyzed in 24-h urine and during 51Cr-EDTA clearance. RESULTS Paricalcitol did not alter plasma levels of renin, AngII, Aldo, or urinary excretion of sodium and potassium. A modest reduction of borderline significance was observed in AER, and paricalcitol abrogated the albuminuric response to L-NMMA. CONCLUSIONS In this randomized, placebo-controlled trial paricalcitol only marginally decreased AER and did not alter circulating levels of renin, AngII or Aldo. The abrogation of the rise in albumin excretion by paricalcitol during NOS blockade may indicate that favourable modulation of renal NO dependency could be involved in mediating reno-protection and survival benefits in CKD. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT01136564.
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