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Wouda RD, Gritter M, Karsten M, Michels EH, Nieuweboer TM, Danser AJ, de Borst MH, Hoorn EJ, Rotmans JI, Vogt L. Kaliuresis and Intracellular Uptake of Potassium with Potassium Citrate and Potassium Chloride Supplements: A Randomized Controlled Trial. Clin J Am Soc Nephrol 2023; 18:1260-1271. [PMID: 37382933 PMCID: PMC10578626 DOI: 10.2215/cjn.0000000000000228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023]
Abstract
BACKGROUND A potassium replete diet is associated with lower cardiovascular risk but may increase the risk of hyperkalemia, particularly in people using renin-angiotensin-aldosterone system inhibitors. We investigated whether intracellular uptake and potassium excretion after an acute oral potassium load depend on the accompanying anion and/or aldosterone and whether this results in altered plasma potassium change. METHODS In this placebo-controlled interventional cross-over trial including 18 healthy individuals, we studied the acute effects of one oral load of potassium citrate (40 mmol), potassium chloride (40 mmol), and placebo in random order after overnight fasting. Supplements were administered after a 6-week period with and without lisinopril pretreatment. Linear mixed effect models were used to compare blood and urine values before and after supplementation and between the interventions. Univariable linear regression was used to determine the association between baseline variables and change in blood and urine values after supplementation. RESULTS During the 4-hour follow-up, the rise in plasma potassium was similar for all interventions. After potassium citrate, both red blood cell potassium-as measure of the intracellular potassium-and transtubular potassium gradient (TTKG)-reflecting potassium secretory capacity-were higher than after potassium chloride or potassium citrate with lisinopril pretreatment. Baseline aldosterone was significantly associated with TTKG after potassium citrate, but not after potassium chloride or potassium citrate with lisinopril pretreatment. The observed TTKG change after potassium citrate was significantly associated with urine pH change during this intervention ( R =0.60, P < 0.001). CONCLUSIONS With similar plasma potassium increase, red blood cell potassium uptake and kaliuresis were higher after an acute load of potassium citrate as compared with potassium chloride alone or pretreatment with lisinopril. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER Potassium supplementation in patients with chronic kidney disease and healthy subjects: effects on potassium and sodium balance, NL7618.
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Affiliation(s)
- Rosa D. Wouda
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Micky Karsten
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Erik H.A. Michels
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Tamar M. Nieuweboer
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - A.H. Jan Danser
- Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Martin H. de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, Groningen, The Netherlands
| | - Ewout J. Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joris I. Rotmans
- Department of Internal Medicine, Division of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Liffert Vogt
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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Scheinman PL, Vocanson M, Thyssen JP, Johansen JD, Nixon RL, Dear K, Botto NC, Morot J, Goldminz AM. Contact dermatitis. Nat Rev Dis Primers 2021; 7:38. [PMID: 34045488 DOI: 10.1038/s41572-021-00271-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/23/2021] [Indexed: 02/04/2023]
Abstract
Contact dermatitis (CD) is among the most common inflammatory dermatological conditions and includes allergic CD, photoallergic CD, irritant CD, photoirritant CD (also called phototoxic CD) and protein CD. Occupational CD can be of any type and is the most prevalent occupational skin disease. Each CD type is characterized by different immunological mechanisms and/or requisite exposures. Clinical manifestations of CD vary widely and multiple subtypes may occur simultaneously. The diagnosis relies on clinical presentation, thorough exposure assessment and evaluation with techniques such as patch testing and skin-prick testing. Management is based on patient education, avoidance strategies of specific substances, and topical treatments; in severe or recalcitrant cases, which can negatively affect the quality of life of patients, systemic medications may be needed.
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Affiliation(s)
- Pamela L Scheinman
- Department of Dermatology, Brigham and Women's Hospital, Boston, MA, USA
| | - Marc Vocanson
- CIRI - Centre International de Recherche en Infectiologie, INSERM, U1111; Univ Lyon; Université Claude Bernard Lyon 1; Ecole Normale Supérieure de Lyon; CNRS, UMR, 5308, Lyon, France
| | - Jacob P Thyssen
- National Allergy Research Centre, Department of Dermatology and Allergy, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jeanne Duus Johansen
- National Allergy Research Centre, Department of Dermatology and Allergy, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Rosemary L Nixon
- Skin Health Institute - Occupational Dermatology Research and Education Centre, Carlton, VIC, Australia
| | - Kate Dear
- Skin Health Institute - Occupational Dermatology Research and Education Centre, Carlton, VIC, Australia
| | - Nina C Botto
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Johanna Morot
- CIRI - Centre International de Recherche en Infectiologie, INSERM, U1111; Univ Lyon; Université Claude Bernard Lyon 1; Ecole Normale Supérieure de Lyon; CNRS, UMR, 5308, Lyon, France
| | - Ari M Goldminz
- Department of Dermatology, Brigham and Women's Hospital, Boston, MA, USA.
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Gong XL, Gu XL, Chen YC, Zhu H, Xia ZN, Li JZ, Lu GC. Chronic preclinical safety evaluation of EPO-018B, a pegylated peptidic erythropoiesis-stimulating agent in monkeys and rats. Toxicol Appl Pharmacol 2016; 307:45-61. [PMID: 27457977 DOI: 10.1016/j.taap.2016.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 07/19/2016] [Accepted: 07/20/2016] [Indexed: 10/21/2022]
Abstract
EPO-018B, a synthetic peptide-based erythropoiesis stimulating agent (ESA), is mainly designed for treatment of anemia caused by chronic renal failure and chemotherapy against cancer. It overcomes the deficiencies of currently approved ESA, including the frequent administration of temperature-sensitive recombinant protein and anti-EPO antibody-mediated pure red cell aplasia (PRCA). This study was designed to evaluate the potential chronic toxicity of EPO-018B. Subcutaneous administration doses were designed as 0, 0.2, 1 and 10mg/kg for six months for 160 rats (20/gender/group) and 0, 0.3, 3 and 20mg/kg for nine months for 32 monkeys (4/gender/group) once every three weeks. The vehicles received the same volume of physiological saline injection. All animals survived to the scheduled necropsies after six weeks (for rats) and fourteen weeks (for monkeys) recovery period, except for the two high-dose female rats and two high-dose male monkeys, which were considered related to the increased RBCs, chronic blood hyperviscosity and chronic cardiac injury. EPO-018B is supposed to be subcutaneously injected once every month and the intended human therapeutic dose is 0.025mg/kg. The study findings at 0.2mg/kg for rats and 0.3mg/kg for monkeys were considered to be the study NOAEL (the no observed adverse effect level), which were more than ten times the intended human therapeutic dose. Higher doses caused adverse effects related to the liver toxicity, cardiotoxicity, appearance of neutralizing antibodies of EPO-018B and the decrease of serum glucose and cholesterol. Most treatment-induced effects were reversible or revealed ongoing recovery upon the discontinuation of treatment. The sequelae occurred in rats and monkeys were considered secondary to exaggerated pharmacology and would less likely occur in the intended patient population. As to the differences between human beings and animals, the safety of EPO-018B need to be further confirmed in the future clinical studies.
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Affiliation(s)
- Xue-Lian Gong
- Department of Hygiene and Toxicology, Second Military Medical University, Shanghai 200433, China
| | - Xiao-Lei Gu
- Department of Hygiene and Toxicology, Second Military Medical University, Shanghai 200433, China
| | - Yong-Chun Chen
- Department of Hygiene and Toxicology, Second Military Medical University, Shanghai 200433, China; Department of Pharmacy, No.422 Hospital, Zhanjiang 524005, China
| | - Hai Zhu
- Department of Hygiene and Toxicology, Second Military Medical University, Shanghai 200433, China
| | - Zhen-Na Xia
- Department of Hygiene and Toxicology, Second Military Medical University, Shanghai 200433, China
| | - Jian-Zhong Li
- Department of Biochemical Pharmacy, Second Military Medical University, Shanghai 200433, China.
| | - Guo-Cai Lu
- Department of Hygiene and Toxicology, Second Military Medical University, Shanghai 200433, China.
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Xu C, Lu A, Wang H, Fang H, Zhou L, Sun P, Yang T. (Pro)Renin receptor regulates potassium homeostasis through a local mechanism. Am J Physiol Renal Physiol 2016; 313:F641-F656. [PMID: 27440776 DOI: 10.1152/ajprenal.00043.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 07/12/2016] [Accepted: 07/18/2016] [Indexed: 11/22/2022] Open
Abstract
(Pro)renin receptor (PRR) is highly expressed in the distal nephron, but it has an unclear functional implication. The present study was conducted to explore a potential role of renal PRR during high K+ (HK) loading. In normal Sprague-Dawley rats, a 1-wk HK intake increased renal expression of full-length PRR and urinary excretion of soluble PRR (sPRR). Administration of PRO20, a decoy peptide antagonist of PRR, in K+-loaded animals elevated plasma K+ level and decreased urinary K+ excretion, accompanied with suppressed urinary aldosterone excretion and intrarenal aldosterone levels. HK downregulated Na+-Cl- cotransporter (NCC) expression but upregulated CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2), renal outer medullary K+ channel (ROMK), calcium-activated potassium channel subunit α1 (α-BK), α-Na+-K+-ATPase (α-NKA), and epithelial Na+ channel subunit β (β-ENaC), all of which were blunted by PRO20. After HK loading was completed, urinary, but not plasma renin, was upregulated, which was blunted by PRO20. The same experiments that were performed using adrenalectomized (ADX) rats yielded similar results. Interestingly, spironolactone treatment in HK-loaded ADX rats attenuated kaliuresis but promoted natriuresis, which was associated with the suppressed responses of β-ENaC, α-NKA, ROMK, and α-BK protein expression. Taken together, we discovered a novel role of renal PRR in regulation of K+ homeostasis through a local mechanism involving intrarenal renin-angiotensin-aldosterone system and coordinated regulation of membrane Na+- and K+-transporting proteins.
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Affiliation(s)
- Chuanming Xu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Aihua Lu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Hong Wang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Hui Fang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Li Zhou
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Peng Sun
- Anesthesiology, Sun Yat-sen University Cancer Center, Guangzhou, China; and
| | - Tianxin Yang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; .,Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah
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Subchronic safety evaluation of EPO-018B, a pegylated peptidic erythropoiesis stimulating agent, after 5-week subcutaneous injection in Cynomolgus monkeys and Sprague–Dawley rats. Food Chem Toxicol 2013; 60:252-62. [DOI: 10.1016/j.fct.2013.07.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/08/2013] [Accepted: 07/11/2013] [Indexed: 11/23/2022]
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Cavinatto JN, de Araujo M, Seguro AC, Carrazza FR, Helou CMB. Study of erythrocyte ATPases in infants evaluated during the recovery phase of severe dehydration caused by diarrhea. Nephron Clin Pract 2006; 103:p164-9. [PMID: 16636594 DOI: 10.1159/000092917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Accepted: 11/27/2005] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Patients severely dehydrated from diarrhea are at risk of developing hyperkalemia consequent to fluid therapy treatment. In parallel with the regulation of external potassium balance by the kidney and gastrointestinal tract, plasma potassium is rapidly regulated by redistribution of potassium between the extracellular and intracellular compartments. Erythrocytes contain ATPases that play a role in this potassium movement. In this study, erythrocyte ATPase effectiveness was evaluated in infants dehydrated from diarrhea and compared to that of healthy infants. METHODS Blood samples were collected from dehydrated and healthy infants. The activity of Na+,K+-ATPase and of an ouabain-insensitive K+-ATPase were assessed. Serum electrolytes and blood pH were also determined. RESULTS No hyperkalemia was found, even in dehydrated infants presenting with severe hyperchloremic metabolic acidosis. In the erythrocytes of dehydrated infants, Na+,K+-ATPase activity was increased correlating positively with the amount of sodium administered. High K+-ATPase activity in the erythrocytes correlated with low plasma potassium. The K+-ATPase activity correlated positively with the amount of potassium administered to dehydrated infants. CONCLUSION These findings suggest that the erythrocytes Na+,K+-ATPase and K+-ATPase both protect against plasma potassium abnormalities in dehydrated infants. In such infants, the risk of hyperkalemia is probably low.
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Affiliation(s)
- José Nélio Cavinatto
- Instituto da Criança, Departamento de Pediatria, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
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Kim CR, Sadowska GB, Petersson KH, Merino M, Sysyn GD, Padbury JF, Stonestreet BS. Effects of postnatal steroids on Na+/K+-ATPase activity and alpha1- and beta1-subunit protein expression in the cerebral cortex and renal cortex of newborn lambs. Reprod Fertil Dev 2006; 18:413-23. [PMID: 16737634 DOI: 10.1071/rd05114] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Accepted: 01/02/2006] [Indexed: 11/23/2022] Open
Abstract
Na(+)/K(+)-ATPase is a membrane-bound enzyme responsible for Na(+)/K(+) translocation across cell membranes. It is essential for the generation of electrochemical gradients, which control the ionic environment necessary for electrical activity and water and electrolyte balance. Newborn infants who are at risk of developing bronchopulmonary dysplasia (BPD) are frequently treated with corticosteroids. Although these infants are at risk for neurological, water and electrolyte abnormalities, there is little information regarding the effects of clinically relevant doses of corticosteroids on Na(+)/K(+)-ATPase activity and protein isoform expression in the brain and kidney of newborns. In the present study, we examined the effects of dexamethasone on cerebral cortical and renal cortical Na(+)/K(+)-ATPase activity and alpha1- and beta1-protein isoform expression in newborn lambs. Lambs were given four injections of a placebo (n = 11) or one of three different doses of dexamethasone (0.01 mg kg(-1), n = 9; 0.25 mg kg(-1), n = 11; or 0.50 mg kg(-1), n = 9) 12 h apart on Postnatal Days 3 and 4 up to 18 h before harvest of the cerebral cortex and renal cortex. We selected doses in a range to approximate those used to treat infants with BPD. Na(+)/K(+)-ATPase activity was measured in membrane preparations as ouabain-sensitive inorganic phosphate liberation from ATP and alpha1- and beta1-subunit abundance by Western immunoblot. Postnatal treatment of lambs with dexamethasone resulted in a 21.4% increase in Na(+)/K(+)-ATPase activity and a 30.4% increase in catalytic alpha1-protein expression in the cerebral cortex at a dose of 0.50 mg kg(-1) dexamethasone, but not at the lower doses. Dexamethasone treatment was not associated with changes in beta1-isoform expression in the cerebral cortex. In the kidney, dexamethasone treatment was not associated with significant changes in Na(+)/K(+)-ATPase activity or alpha1- or beta1-isoform expression for the doses we examined. Therefore, clinically relevant corticosteroid treatment exerts dose-related, differential organ-specific effects on Na(+)/K(+)-ATPase activity and protein isoform expression in newborn lambs.
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Affiliation(s)
- Chang-Ryul Kim
- Pediatrics, Women & Infants' Hospital of Rhode Island and Brown Medical School, Providence, RI 02905-2499, USA
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Wald H, Garty H, Palmer LG, Popovtzer MM. Differential regulation of ROMK expression in kidney cortex and medulla by aldosterone and potassium. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:F239-45. [PMID: 9691014 DOI: 10.1152/ajprenal.1998.275.2.f239] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study explores the role of K+ and aldosterone in the regulation of mRNA of the ATP-sensitive, inwardly rectifying K+ channel, ROMK, in the rat kidney. K+ deficiency downregulated ROMK mRNA in cortex to 47.1 +/- 5.1% of control (P < 0.001) and in medulla to 56.1 +/- 3. 4% (P < 0.001). High-K+ diet slightly increased ROMK mRNA in medulla to 122 +/- 9% (P < 0.05 vs. control). Adrenalectomy (Adx) downregulated cortical ROMK mRNA to 30.7 +/- 6.8% (P < 0.001 vs. control), and increased it in medulla to 138 +/- 12.9% (P < 0.02 vs. control). In Adx rats, K+ deficiency decreased ROMK mRNA in cortex and medulla similar to intact rats. The alpha1- and beta1-Na-K-ATPase subunits were regulated in parallel to that of ROMK. In medulla, ROMK mRNA correlated with serum K+ concentration at R = 0.9406 (n = 6, P < 0.001) and alpha1-Na-K-ATPase mRNA at R = 0.9756 (n = 6, P < 0.001). ROMK2 also correlated with serum K+ concentration (R = 0.895; n = 6, P < 0.01). These results show that cortical ROMK expression is regulated by aldosterone and K+, whereas the medullary ROMK mRNA is regulated by serum K+.
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Affiliation(s)
- H Wald
- Nephrology and Hypertension Services, Hadassah University Hospital, Jerusalem 91120, Israel
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Golik A, Weissgarten J, Evans S, Cohen N, Averbukh Z, Zaidenstein R, Cotariu D, Modai D. Erythrocyte Na+, K+ and Ca2+, Mg(2+)-ATPase activities in hypertensives on angiotensin-converting enzyme inhibitors. Clin Biochem 1996; 29:249-54. [PMID: 8740511 DOI: 10.1016/0009-9120(95)02030-p] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To investigate erythrocyte membrane Na+, K(+)- and Ca2+, Mg(2+)-ATPase activities in newly diagnosed hypertensive patients before and after 2, 4, and 6 months of treatment with enalapril or captopril as monotherapy. METHODS AND RESULTS Na+, K(+)-ATPase activity (nmol ATP hydrolysed/min per mg protein) rose by 6 months of treatment in both groups when values were compared in each treated group over time (4.5 +/- 0.8 to 9.9 +/- 1.2; 4.9 +/- 0.8 to 10.5 +/- 1.7, respectively, p < 0.001 for both). When the treated groups were compared with controls at each period of time, Na+, K(+)-ATPase activity was higher at months 4 and 6 (p < 0.001) for both groups, respectively). Ca2+, Mg(2+)-ATPase activity (nmol ATP hydrolyzed/min per milligram protein) in the absence and in the presence of calmodulin increased in the enalapril (6.4 +/- 0.7 to 8.9 +/- 0.95, p < 0.05; 13.4 +/- 1.2 to 17.2 +/- 1.2, p < 0.05, respectively) and captopril (7.0 +/- 0.6 to 8.5 +/- 0.7; 14.4 +/- 1.1 to 16.0 +/- 1.0, p < 0.05, respectively) groups after 6 months of treatment compared within each treated group over time. When patient groups were compared with controls at time 0, 2, 4, and 6 months, the pump activity was higher in the treated groups at 6 months. CONCLUSION The long-term enhancement of cell membrane Na+, K(+)-and Ca2+, Mg(2+)-ATPase activity associated with enalapril and captopril therapy may represent a specific effect of these agents or alternatively, a nonspecific outcome of blood pressure reduction.
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Affiliation(s)
- A Golik
- Department of Medicine A, Assaf Harofeh Medical Center, Tel Aviv University, Israel
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Pácha J, Pohlová I. The influence of high salt intake on intestinal Na,K-ATPase in Wistar and Dahl rats. ACTA PHYSIOLOGICA SCANDINAVICA 1993; 148:69-75. [PMID: 8392776 DOI: 10.1111/j.1748-1716.1993.tb09533.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The Na,K-ATPase of intestinal mucosa was compared in Wistar (W), salt-sensitive (DS) and salt-resistant (DR) Dahl rats fed a low-salt (LS) and high-salt (HS) diet. ATPase activity and the kinetics of its activation by Na+ were determined in three intestinal segments (jejunum, ileum, distal colon). There were demonstrated only small differences in the affinity for Na+ among the strains studied but we found a considerable profile of Na,K-ATPase activity along the intestine in all strains; the activity was higher in jejunum and lower in ileum and distal colon. Chronic salt loading decreased the affinity of Na,K-ATPase for Na+ but had no effect on Vmax. The changes in salt intake were accompanied by different response of plasma aldosterone in particular strains. According to the stimulation of aldosterone level by LS diet the sensitivity of the strains was DR > W > DS. HS diet suppressed aldosterone level to similar values in all strains. The data indicate that the kinetics of intestinal Na,K-ATPase and its response to HS intake is independent of the genotype of the rats.
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Affiliation(s)
- J Pácha
- Institute of Physiology, Czechoslovak Academy of Sciences, Prague
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Celsi G, Ståhl J, Wang ZM, Nishi A. Adrenocorticoid regulation of Na+,K(+)-ATPase in adult rat kidney: effects on post-translational processing and mRNA abundance. ACTA PHYSIOLOGICA SCANDINAVICA 1992; 145:85-91. [PMID: 1322020 DOI: 10.1111/j.1748-1716.1992.tb09342.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The mechanisms by which adreno-corticoid hormones regulate Na+,K(+)-ATPase in adult kidney were studied in adrenalectomized (Adx) rats. Five days after adrenalectomy, Na+,K(+)-ATPase activity was significantly reduced in the renal cortex homogenate (C = 13.0 +/- 0.8 vs. Adx = 7.1 +/- 0.7 mumol Pi mg-1 protein h-1) and in renal microsomes (C = 30.3 +/- 1.9 vs Adx = 14.6 +/- 1.3 mumol Pi mg-1 protein h-1). Glucocorticoid replacement treatment of adrenalectomized rats with betamethasone (20 micrograms kg-1 body wt twice daily for 5 days) effectively counteracted the observed reduction in Na+,K(+)-ATPase activity. In cortical homogenate the protein level of alpha 1 and beta 1 subunits measured in immunoblots was not significantly different in Adx and control rats, indicating that 5 days after adrenalectomy the alpha 1 and beta 1 subunits were present in renal cortical cells to almost normal extent but could not be assembled into a transmembrane functional unit. In support of this conclusion we found that the protein level of both the alpha 1 and beta 1 subunits was significantly lower (P less than 0.001 for both subunits) in microsomes from Adx than in control rats. The mRNA abundance for alpha 1 and beta 1 subunits were not lower in Adx as compared to control rats 1 and 5 days after surgery. However, if Adx rats were given a single dose of betamethasone (600 micrograms kg-1 body wt), a significant 2-fold increase in both alpha 1 and beta 1 mRNAs was observed (P less than 0.05 for both subunits).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G Celsi
- Department of Paediatrics, St. Göran's Children's Hospital, Karolinska Institute, Stockholm, Sweden
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