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Na +/K +-pump and neurotransmitter membrane receptors. INVERTEBRATE NEUROSCIENCE 2018; 19:1. [PMID: 30488358 PMCID: PMC6267510 DOI: 10.1007/s10158-018-0221-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/17/2018] [Indexed: 02/06/2023]
Abstract
Na+/K+-pump is an electrogenic transmembrane ATPase located in the outer plasma membrane of cells. The Na+/K+-ATPase pumps 3 sodium ions out of cells while pumping 2 potassium ions into cells. Both cations move against their concentration gradients. This enzyme's electrogenic nature means that it has a chronic role in stabilizing the resting membrane potential of the cell, in regulating the cell volume and in the signal transduction of the cell. This review will mainly consider the role of the Na+/K+-pump in neurons, with an emphasis on its role in modulating neurotransmitter receptor. Most of the literature on the modulation of neurotransmitter receptors refers to the situation in the mammalian nervous system, but the position is likely to be similar in most, if not all, invertebrate nervous systems.
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O'Neill J, Healy V, Johns EJ. Intrarenal Mas and AT 1 receptors play a role in mediating the excretory actions of renal interstitial angiotensin-(1-7) infusion in anaesthetized rats. Exp Physiol 2017; 102:1700-1715. [PMID: 28940861 DOI: 10.1113/ep086513] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 08/25/2017] [Indexed: 12/17/2022]
Abstract
NEW FINDINGS What is the central question of this study? Dietary sodium manipulation alters the magnitude of angiotensin-(1-7) [Ang-(1-7)]-induced natriuresis. The present study sought to determine whether this was related to relative changes in the activity of intrarenal Mas and/or AT1 receptors. What is the main finding and its importance? Angiotensin-(1-7)-induced diuresis and natriuresis is mediated by intrarenal Mas receptors. However, intrarenal AT1 receptor blockade also had an inhibitory effect on Ang-(1-7)-induced natriuresis and diuresis. Thus, Ang-(1-7)-induced increases in sodium and water excretion are dependent upon functional Mas and AT1 receptors. We investigated whether angiotensin-(1-7) [Ang-(1-7)]-induced renal haemodynamic and excretory actions were solely dependent upon intrarenal Mas receptor activation or required functional angiotensin II type 1 (AT1 ) receptors. The renin-angiotensin system was enhanced in anaesthetized rats by prior manipulation of dietary sodium intake. Angiotensin-(1-7) and AT1 and Mas receptor antagonists were infused into the kidney at the corticomedullary border. Mas receptor expression was measured in the kidney. Mean arterial pressure, urine flow and fractional sodium excretion were 93 ± 4 mmHg, 46.1 ± 15.7 μl min-1 kg-1 and 1.4 ± 0.3%, respectively, in the normal-sodium group and 91 ± 2 mmHg, 19.1 ± 3.3 μl min-1 kg-1 and 0.7 ± 0.2%, respectively, in the low-sodium group. Angiotensin-(1-7) infusion had no effect on mean arterial pressure in rats receiving a normal-sodium diet but decreased it by 4 ± 5% in rats receiving a low-sodium diet (P < 0.05). Interstitial Ang-(1-7) infusion increased urine flow twofold and fractional sodium excretion threefold (P < 0.05) in rats receiving a normal-sodium diet and to a greater extent, approximately three- and fourfold, respectively, in rats receiving the low-sodium diet (both P < 0.05). Angiotensin-(1-7)-induced increases in urine flow and fractional sodium excretion were absent in both dietary groups during intrarenal AT1 or Mas receptor inhibition after either losartan or A-779, respectively. Thus, AT1 receptor activation, as well as Mas receptor activation, plays an essential role in mediating Ang-(1-7)-induced natriuresis and diuresis. Whether this is because Ang-(1-7) partly antagonizes AT1 receptors or whether Ang-(1-7)-induced natriuresis is mediated through AT1 -Mas receptor dimerization remains unclear.
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Affiliation(s)
- Julie O'Neill
- Department of Physiology, University College Cork, Cork, Republic of Ireland
| | - Vincent Healy
- Department of Physiology, University College Cork, Cork, Republic of Ireland
| | - Edward J Johns
- Department of Physiology, University College Cork, Cork, Republic of Ireland
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Rukavina Mikusic NL, Kouyoumdzian NM, Rouvier E, Gironacci MM, Toblli JE, Fernández BE, Choi MR. Regulation of Dopamine Uptake by Vasoactive Peptides in the Kidney. SCIENTIFICA 2016; 2016:6302376. [PMID: 27635280 PMCID: PMC5011208 DOI: 10.1155/2016/6302376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 06/19/2016] [Accepted: 07/03/2016] [Indexed: 06/06/2023]
Abstract
Considering the key role of renal dopamine in tubular sodium handling, we hypothesized that c-type natriuretic peptide (CNP) and Ang-(1-7) may regulate renal dopamine availability in tubular cells, contributing to Na(+), K(+)-ATPase inhibition. Present results show that CNP did not affect either (3)H-dopamine uptake in renal tissue or Na(+), K(+)-ATPase activity; meanwhile, Ang-(1-7) was able to increase (3)H-dopamine uptake and decreased Na(+), K(+)-ATPase activity in renal cortex. Ang-(1-7) and dopamine together decreased further Na(+), K(+)-ATPase activity showing an additive effect on the sodium pump. In addition, hydrocortisone reversed Ang-(1-7)-dopamine overinhibition on the enzyme, suggesting that this inhibition is closely related to Ang-(1-7) stimulation on renal dopamine uptake. Both anantin and cANP (4-23-amide) did not modify CNP effects on (3)H-dopamine uptake by tubular cells. The Mas receptor antagonist, A-779, blocked the increase elicited by Ang-(1-7) on (3)H-dopamine uptake. The stimulatory uptake induced by Ang-(1-7) was even more pronounced in the presence of losartan, suggesting an inhibitory effect of Ang-(1-7) on AT1 receptors on (3)H-dopamine uptake. By increasing dopamine bioavailability in tubular cells, Ang-(1-7) enhances Na(+), K(+)-ATPase activity inhibition, contributing to its natriuretic and diuretic effects.
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Affiliation(s)
- N. L. Rukavina Mikusic
- Instituto de Investigaciones Cardiológicas ININCA, UBA-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
| | - N. M. Kouyoumdzian
- Instituto de Investigaciones Cardiológicas ININCA, UBA-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
| | - E. Rouvier
- Instituto de Investigaciones Cardiológicas ININCA, UBA-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
- Cátedras de Anatomía e Histología, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
| | - M. M. Gironacci
- Cátedras de Química Biológica, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
| | - J. E. Toblli
- Instituto de Investigaciones Cardiológicas ININCA, UBA-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
- Laboratorio de Medicina Experimental, Hospital Alemán, Buenos Aires, Argentina
| | - B. E. Fernández
- Instituto de Investigaciones Cardiológicas ININCA, UBA-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
| | - M. R. Choi
- Instituto de Investigaciones Cardiológicas ININCA, UBA-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
- Cátedras de Anatomía e Histología, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina
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Simões e Silva AC, Silveira KD, Ferreira AJ, Teixeira MM. ACE2, angiotensin-(1-7) and Mas receptor axis in inflammation and fibrosis. Br J Pharmacol 2014; 169:477-92. [PMID: 23488800 DOI: 10.1111/bph.12159] [Citation(s) in RCA: 404] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 02/04/2013] [Accepted: 02/13/2013] [Indexed: 12/14/2022] Open
Abstract
Recent advances have improved our understanding of the renin-angiotensin system (RAS). These have included the recognition that angiotensin (Ang)-(1-7) is a biologically active product of the RAS cascade. The identification of the ACE homologue ACE2, which forms Ang-(1-7) from Ang II, and the GPCR Mas as an Ang-(1-7) receptor have provided the necessary biochemical and molecular background and tools to study the biological significance of Ang-(1-7). Most available evidence supports a counter-regulatory role for Ang-(1-7) by opposing many actions of Ang II on AT₁ receptors, especially vasoconstriction and proliferation. Many studies have now shown that Ang-(1-7) by acting via Mas receptor exerts inhibitory effects on inflammation and on vascular and cellular growth mechanisms. Ang-(1-7) has also been shown to reduce key signalling pathways and molecules thought to be relevant for fibrogenesis. Here, we review recent findings related to the function of the ACE2/Ang-(1-7)/Mas axis and focus on the role of this axis in modifying processes associated with acute and chronic inflammation, including leukocyte influx, fibrogenesis and proliferation of certain cell types. More attention will be given to the involvement of the ACE2/Ang-(1-7)/Mas axis in the context of renal disease because of the known relevance of the RAS for the function of this organ and for the regulation of kidney inflammation and fibrosis. Taken together, this knowledge may help in paving the way for the development of novel treatments for chronic inflammatory and renal diseases.
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Affiliation(s)
- A C Simões e Silva
- Departamento de Pediatria, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Santos RAS, Ferreira AJ, Verano-Braga T, Bader M. Angiotensin-converting enzyme 2, angiotensin-(1-7) and Mas: new players of the renin-angiotensin system. J Endocrinol 2013; 216:R1-R17. [PMID: 23092879 DOI: 10.1530/joe-12-0341] [Citation(s) in RCA: 363] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Angiotensin (Ang)-(1-7) is now recognized as a biologically active component of the renin-angiotensin system (RAS). Ang-(1-7) appears to play a central role in the RAS because it exerts a vast array of actions, many of them opposite to those attributed to the main effector peptide of the RAS, Ang II. The discovery of the Ang-converting enzyme (ACE) homolog ACE2 brought to light an important metabolic pathway responsible for Ang-(1-7) synthesis. This enzyme can form Ang-(1-7) from Ang II or less efficiently through hydrolysis of Ang I to Ang-(1-9) with subsequent Ang-(1-7) formation by ACE. In addition, it is now well established that the G protein-coupled receptor Mas is a functional binding site for Ang-(1-7). Thus, the axis formed by ACE2/Ang-(1-7)/Mas appears to represent an endogenous counterregulatory pathway within the RAS, the actions of which are in opposition to the vasoconstrictor/proliferative arm of the RAS consisting of ACE, Ang II, and AT(1) receptor. In this brief review, we will discuss recent findings related to the biological role of the ACE2/Ang-(1-7)/Mas arm in the cardiovascular and renal systems, as well as in metabolism. In addition, we will highlight the potential interactions of Ang-(1-7) and Mas with AT(1) and AT(2) receptors.
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Affiliation(s)
- Robson A S Santos
- Departments of Physiology and Biophysics Morphology, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
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Abstract
The renin-angiotensin system (RAS) constitutes one of the most important hormonal systems in the physiological regulation of blood pressure through renal and nonrenal mechanisms. Indeed, dysregulation of the RAS is considered a major factor in the development of cardiovascular pathologies, including kidney injury, and blockade of this system by the inhibition of angiotensin converting enzyme (ACE) or blockade of the angiotensin type 1 receptor (AT1R) by selective antagonists constitutes an effective therapeutic regimen. It is now apparent with the identification of multiple components of the RAS within the kidney and other tissues that the system is actually composed of different angiotensin peptides with diverse biological actions mediated by distinct receptor subtypes. The classic RAS can be defined as the ACE-Ang II-AT1R axis that promotes vasoconstriction, water intake, sodium retention, and other mechanisms to maintain blood pressure, as well as increase oxidative stress, fibrosis, cellular growth, and inflammation in pathological conditions. In contrast, the nonclassical RAS composed primarily of the AngII/Ang III-AT2R pathway and the ACE2-Ang-(1-7)-AT7R axis generally opposes the actions of a stimulated Ang II-AT1R axis through an increase in nitric oxide and prostaglandins and mediates vasodilation, natriuresis, diuresis, and reduced oxidative stress. Moreover, increasing evidence suggests that these non-classical RAS components contribute to the therapeutic blockade of the classical system to reduce blood pressure and attenuate various indices of renal injury, as well as contribute to normal renal function.
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Affiliation(s)
- Mark C Chappell
- The Hypertension & Vascular Disease Center, Department of Physiology & Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
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7
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Angiotensin converting enzyme 2, Angiotensin-(1-7), and receptor MAS axis in the kidney. Int J Hypertens 2012; 2012:414128. [PMID: 22518283 PMCID: PMC3296191 DOI: 10.1155/2012/414128] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 11/02/2011] [Indexed: 02/07/2023] Open
Abstract
In the past few years the understanding of the renin-angiotensin system (RAS) has improved, helping to better define the role of this system in physiological conditions and in human diseases. Besides Angiotensin (Ang) II, the biological importance of other Ang fragments was progressively evidenced. In this regard, Angiotensin- (Ang-) (1-7) was recognized as a biologically active product of the RAS cascade with a specific receptor, the G-protein-coupled receptor Mas, and that is mainly formed by the action of the angiotensin-converting enzyme (ACE) homolog enzyme, ACE2, which converts Ang II into Ang-(1-7). Taking into account the biological effects of these two mediators, Ang II and Ang-(1-7), the RAS can be envisioned as a dual function system in which the vasoconstrictor/proliferative or vasodilator/antiproliferative actions are primarily driven by the balance between Ang II and Ang-(1-7), respectively. In this paper, we will discuss our current understanding of the ACE2/Ang-(1-7)/Mas axis of the RAS in renal physiology and in the pathogenesis of primary hypertension and chronic kidney disease.
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Grahnquist L, Chen M, Gerasev A, Aizman R, Celsi G. Regulation of K+
transport in the rat distal colon via angiotensin II subtype receptors and K+
-pathways. ACTA ACUST UNITED AC 2008; 171:145-51. [PMID: 11350274 DOI: 10.1046/j.1365-201x.2001.00791.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The role of angiotensin subtype-1 (AT1) and -2 (AT2) receptors in mediating the effects of angiotensin II (ANG II) on several K+ transporters was studied in rat distal colon using an Ussing chamber. Angiotensin II induced K+ secretion at two different doses. Secretion occurred at 10-(8) and 10-(4) M, as a result of an increase in serosal-to-mucosal flux (Js-m). The ANG II-induced stimulation of Js-m at a low dose (10-(8) M) was abolished by PD123319 while losartan did not alter the low-dose ANG II-dependent increase in Js-m. In contrast, the increase in Js-m induced by a high-dose of ANG II (10-(4) M) was blocked by losartan, whereas PD123319 partially reduced the stimulatory effect. In the presence of both blockers, high-dose ANG II induced an inhibition of basal Js-m. Low-dose ANG II activated the barium-sensitive K+ channels, whereas the Na+, K+, 2Cl- cotransporter and the Na+, K+ -ATPase pump were unchanged. At the high dose, ANG II activated the barium-sensitive K+ channels and the Na+, K+, 2Cl- cotransporter and inhibited the Na+, K+ -ATPase pump. These data indicate that ANG II stimulates serosal-to-mucosal K+ flux in the rat distal colon at high and low doses via different receptors and K+ transporters.
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Affiliation(s)
- L Grahnquist
- Department of Paediatrics, Huddinge University Hospital and Department of Woman and Child Health, Astrid Lindgren Children's Hospital, Karolinska Institutet, Stockholm, Sweden
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Correa AH, Choi MR, Gironacci M, Valera MS, Fernández BE. Signaling pathways involved in atrial natriuretic factor and dopamine regulation of renal Na+, K+ -ATPase activity. ACTA ACUST UNITED AC 2006; 138:26-31. [PMID: 17005263 DOI: 10.1016/j.regpep.2006.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 07/28/2006] [Accepted: 08/04/2006] [Indexed: 12/22/2022]
Abstract
Dopamine (DA) and atrial natriuretic factor (ANF) share a number of physiological effects. We hypothesized that ANF and the renal dopaminergic system could interact and enhance the natriuretic and diuretic effects of the peptide. We have previously reported that the ANF-stimulated DA uptake in renal tubular cells is mediated by the natriuretic peptide type-A receptor (NPR-A). Our aim was to investigate the signaling pathways that mediate ANF effects on renal 3H-DA uptake. Methylene blue (10 microM), an unspecific inhibitor of guanylate cyclase (GC), blunted ANF elicited increase of DA uptake. ODQ (10 microM) a specific inhibitor of soluble GC, did not modify DA uptake and did not reverse ANF-induced increase of DA uptake; then the participation of nitric oxide-dependent pathways must be discarded. The second messenger was the cGMP since the analogous 125 microM 8-Br-cGMP mimicked ANF effects. The specific inhibitor of the protein kinase G (PKG), KT 5823 (1 microM) blocked ANF effects indicating that PKG is involved. We examined if ANF effects on DA uptake were able to modify Na+, K+ -adenosine triphosphatase (Na+, K+ -ATPase) activity. The experiments were designed by means of inhibition of renal DA synthesis by carbidopa and neuronal DA uptake blocked by nomifensine. In these conditions renal Na+, K+ -ATPase activity was increased, in agreement with the decrease of DA availability. When in similar conditions, exogenous DA was added to the incubation medium, the activity of the enzyme tended to decrease, following to the restored availability of DA. The addition of ANF alone had similar effects to the addition of DA on the sodium pump, but when both were added together, the activity of Na(+), K(+)-ATPase was decreased. Moreover, the extraneuronal uptake blocker, hydrocortisone, inhibited the latter effect. In conclusion, ANF stimulates extraneuronal DA uptake in external cortex tissues by activation of NPR-A receptors coupled to GC and it signals through cGMP as second messenger and PKG. Dopamine and ANF may achieve their effects through a common pathway that involves reversible deactivation of renal tubular Na+, K+ -ATPase activity. This mechanism demonstrates a DA-ANF relationship involved in the modulation of both decreased sodium reabsorption and increased natriuresis.
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Affiliation(s)
- Alicia H Correa
- Cátedras de Fisiopatología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, IQUIFIB CONICET, Junín 956 piso 5, 1113 Buenos Aires, Argentina.
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10
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Oudot A, Vergely C, Ecarnot-Laubriet A, Rochette L. Pharmacological concentration of angiotensin-(1-7) activates NADPH oxidase after ischemia-reperfusion in rat heart through AT1 receptor stimulation. ACTA ACUST UNITED AC 2005; 127:101-10. [PMID: 15680476 DOI: 10.1016/j.regpep.2004.10.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Revised: 10/20/2004] [Accepted: 10/27/2004] [Indexed: 11/15/2022]
Abstract
The cardiovascular role of angiotensin-(1-7), especially in the functional and metabolic alterations associated with ischemia-reperfusion (IR), is still not clearly defined. Our objective was to evaluate the cardiac effects of angiotensin-(1-7), the receptors involved, and their relationships with NADPH oxidase activation under non-ischemic conditions and, during an ischemia-reperfusion sequence. Isolated perfused rat hearts underwent 45 min of non-ischemic perfusion, or 30 min of global ischemia followed by 30 min of reperfusion. Angiotensin-(1-7) and/or AT1 receptor blocker losartan or angiotensin-(1-7) receptor antagonist (D-Ala7)-angiotensin-(1-7) were perfused. Our results showed that angiotensin-(1-7) was without effect at low concentrations (10(-10) to 10(-7) M). At a pharmacological concentration, 0.5 microM angiotensin-(1-7) induced vasoconstriction, which was antagonised by losartan. After ischemia, we noted a partial recovery of functional parameters, which was not modified by any of the treatments. The expression of AT1 receptor mRNA was increased by ischemia-reperfusion, except in (D-Ala7)-angiotensin-(1-7) treated hearts. Angiotensin-(1-7) further increased the AT1 expression. NADPH oxidase activity was enhanced in 0.5 microM angiotensin-(1-7)-treated hearts subjected to ischemia-reperfusion, this effect was totally reversed by losartan. This is the first time that it has been shown that, in the heart, angiotensin-(1-7) at pharmacological concentration activates NADPH oxidase, an enzyme thought to be involved in several angiotensin II effects.
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Affiliation(s)
- Alexandra Oudot
- Laboratoire de Physiopathologie et Pharmacologie, Cardio-vasculaires Expérimentales, IFR no. 100, Facultés de Médecine et Pharmacie, 7, Boulevard Jeanne d'Arc-BP 87900, 21079 Dijon, France.
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Caruso-Neves C, Provenzano K, Luz FF, Santos FMR, Fernandes MS, Leão-Ferreira LR, Lopes AG. Bradykinin counteracts the stimulatory effect of angiotensin-(1-7) on the proximal tubule Na+ -ATPase activity through B2 receptor. REGULATORY PEPTIDES 2003; 110:207-12. [PMID: 12573801 DOI: 10.1016/s0167-0115(02)00213-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recently, we demonstrated that angiotensin-(1-7) (Ang-(1-7)) stimulates the Na(+)-ATPase activity through a losartan-sensitive angiotensin receptor, whereas bradykinin inhibits the enzyme activity through the B(2) receptor [Regul. Pept. 91 (2000) 45; Pharmacol. Rev. 32 (1980) 1]. In the present paper, the effect of bradykinin (BK) on Ang-(1-7)-stimulated Na(+)-ATPase activity was evaluated. Preincubation of Na(+)-ATPase with 10(-9) M Ang-(1-7) increases enzyme activity from 7.9+/-0.9 to 14.1+/-1.5 nmol Pi mg(-1) min(-1), corresponding to an increase of 79% (p<0.05). This effect is reverted by bradykinin in a dose-dependent manner (10(-14)-10(-8) M), reaching maximal inhibitory effect at 10(-9) M. Des-Arg(9) bradykinin (DABK), an agonist of B(1) receptor, at the concentrations of 10(-9)-10(-7) M, does not mimic the BK inhibitory effect, and des-Arg(9)-[Leu(8)]-BK (DALBK), a B(1) receptor antagonist, at the concentrations of 10(-10)-10(-7) M, does not prevent the inhibitory effect of BK on Ang-(1-7)-stimulated enzyme. On the other hand, HOE 140, an antagonist of B(2) receptor, abolishes the inhibitory effect of BK on the Ang-(1-7)-stimulated enzyme in a dose-dependent manner, reaching maximal effect at 10(-7) M. Taken together, these data indicate that stimulation of B(2) receptors by BK can counteract the stimulatory effect of Ang-(1-7) on the proximal tubule Na(+)-ATPase activity.
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Affiliation(s)
- C Caruso-Neves
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS-Bloco G, 21949-900, Rio de Janeiro, RJ, Brazil
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López Ordieres MG, Rodríguez de Lores Arnaiz G. Neurotensin effect on Na+, K+-ATPase is CNS area- and membrane-dependent and involves high affinity NT1 receptor. Neurochem Res 2002; 27:1555-61. [PMID: 12512960 DOI: 10.1023/a:1021612825025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have previously shown that peptide neurotensin inhibits cerebral cortex synaptosomal membrane Na+, K+-ATPase, an effect fully prevented by blockade of neurotensin NT1 receptor by antagonist SR 48692. The work was extended to analyze neurotensin effect on Na+, K+-ATPase activity present in other synaptosomal membranes and in CNS myelin and mitochondrial fractions. Results indicated that, besides inhibiting cerebral cortex synaptosomal membrane Na+, K+-ATPase, neurotensin likewise decreased enzyme activity in homologous striatal membranes as well as in a commercial preparation obtained from porcine cerebral cortex. However, the peptide failed to alter either Na+, K+-ATPase activity in cerebellar synaptosomal and myelin membranes or ATPase activity in mitochondrial preparations. Whenever an effect was recorded with the peptide, it was blocked by antagonist SR 48692, indicating the involvement of the high affinity neurotensin receptor (NT1), as well as supporting the contention that, through inhibition of ion transport at synaptic membrane level, neurotensin plays a regulatory role in neurotransmission.
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Affiliation(s)
- María Graciela López Ordieres
- Instituto de Biología Celular y Neurociencias Prof. E. De Robertis, PROBICENE-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 1121-Buenos Aires, Argentina
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14
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Gonzales S, Noriega GO, Tomaro ML, Peña C. Angiotensin-(1-7) stimulates oxidative stress in rat kidney. REGULATORY PEPTIDES 2002; 106:67-70. [PMID: 12047912 DOI: 10.1016/s0167-0115(02)00032-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effect of two different doses of angiotensin-(1-7) and angiotensin II on the oxidative stress generation was analyzed in rat kidney. Animals were injected intraperitoneally with a single dose of angiotensin-(1-7) or angiotensin II (20 or 50 nmol/kg body weight) and killed 3 h after injection. Production of thiobarbituric acid reactive substances (TBARS), measured as indicator of oxidative stress induction, was significantly increased in rat kidney after Ang-(1-7) administration up to 30% and 50% over controls, at 20 and 50 nmol/kg, respectively. Reduced glutathione (GSH), the most important soluble antioxidant defense in mammalian cells, showed a significant decrease of 13% and 20% at 20 and 50 nmol/kg of angiotensin-(1-7), respectively. When the antioxidant enzyme activities were determined, it was found that catalase activity was not altered by the assayed angiotensin-(1-7) doses while superoxide dismutase and glutathione peroxidase activities were significantly reduced by injection of 20 nmol/kg (34% and 13%, with respect to controls) and 50 nmol/kg of angiotensin-(1-7) (54% and 22%, respectively). In contrast, angiotensin II injections did not produce significant changes neither in TBARS levels nor in soluble and enzymatic defense parameters at the two doses used in this work. These results suggest that angiotensin-(1-7) is undoubtedly related to oxidative stress induction.
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Affiliation(s)
- Soledad Gonzales
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
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15
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Lara LS, Bica RBS, Sena SLF, Correa JS, Marques-Fernandes MF, Lopes AG, Caruso-Neves C. Angiotensin-(1-7) reverts the stimulatory effect of angiotensin II on the proximal tubule Na(+)-ATPase activity via a A779-sensitive receptor. REGULATORY PEPTIDES 2002; 103:17-22. [PMID: 11738244 DOI: 10.1016/s0167-0115(01)00322-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Recently, we demonstrated that the stimulatory effect of Ang II on the Na(+)-ATPase activity in proximal tubules is reversed, in a dose-dependent manner, by Ang-(1-7) [Biochim. Biophys. Acta 1467 (2000) 189]. In the present paper, we characterized the receptor involved in this phenomenon. The preincubation of the Na(+)-ATPase with 10(-8) M Ang II increases the enzyme activity from 7.50+/-0.02 (control) to 12.40+/-1.50 nmol Pi mg(-1) min(-1) (p<0.05). Addition of 10(-9) M Ang-(1-7) completely reverts this effect returning the ATPase activity to the control level. This effect seems to be specific to Ang-(1-7) since Ang III (10(-12)-10(-8) M) does not modify the stimulation of the renal proximal tubule Na(+)-ATPase activity by Ang II. Saralasin abolishes the Ang-(1-7) effect in a dose-dependent manner being the maximal effect obtained at 10(-11) M. The increase in A779 concentration (from 10(-12) to 10(-7) M), a specific Ang-(1-7) antagonist, also abolishes the Ang-(1-7) effect. On the other hand, PD123319 (10(-8)-10(-6) M), an AT(2) antagonist receptor, and losartan (10(-12)-10(-7) M), an AT(1) antagonist receptor, does not modify the effect of Ang-(1-7). Taken together, these data indicate that Ang-(1-7) reverts the stimulatory effect of Ang II on the Na(+)-ATPase activity in proximal tubule through a A779-sensitive receptor.
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Affiliation(s)
- Lucienne S Lara
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS-Bloco G, 21949-900, RJ, Rio de Janeiro, Brazil
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Gironacci MM, Rodríguez-Fermepín M, Vatta M, Fernandez BE, Rubio M, Peña C. Angiotensin-(1-7) does not affect norepinephrine neuronal uptake or catabolism in rat hypothalamus and atria. Cell Mol Neurobiol 2000; 20:773-9. [PMID: 11100983 DOI: 10.1023/a:1007063111479] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
1. Since we previously reported that angiotensin-(1-7) [Ang-(1-7)] increases or inhibits norepinephrine (NE) release in rat atria or hypothalamus, respectively, the present work was undertaken to investigate the effect of the heptapeptide on NE neuronal uptake and metabolism in atria and hypothalamus isolated from rats. 2. Ang II (1-10 microM) caused a decrease in neuronal NE uptake in both atria and hypothalami isolated from rats. On the contrary, tissues incubated with [3H]NE in the presence of 0.1-10 microM Ang-(1-7) showed no modification in [3H]NE content with respect to the control group, suggesting that the heptapeptide did not modify [3H]NE neuronal uptake. 3. To study the effect of the heptapeptide on NE catabolism, monoamine-oxidase (MAO) and catechol-O-methyltransferase (COMT) activities were determined. Pretreatment of the tissue with Ang-(1-7) (0.1-1.0 microM) showed a tendency to diminish MAO activity in rat atria, while no significant changes were observed in hypothalamic MAO activity. Moreover, the heptapeptide (0.1-1.0 microM) did not affect central COMT activity with respect to the control group. 4. Present results allow us to conclude that Ang-(1-7) interacts with noradrenergic neurotransmission by increasing or inhibiting NE release at the peripheral and central levels, respectively, without affecting either the neurotransmitter neuronal uptake or catabolism.
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Affiliation(s)
- M M Gironacci
- Departamento de Química Biológica and Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
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Abstract
Oxidative metabolism is very active in brain, where large amounts of chemical energy as ATP molecules are consumed, mostly required to maintain cellular Na+/K+ gradients through the participation of the sodium pump (Na+,K+-ATPase), whose activity is selectively and potently inhibited by the alkaloid ouabain. Na+/K+ gradients are involved in nerve impulse propagation, in neurotransmitter release and cation homeostasis in the nervous system. Likewise, enzyme activity modulation is crucial for maintaining normal blood pressure and cardiovascular contractility as well as renal sodium excretion. The present article reviews the progress in disclosing putative ouabain-like substances, examines their denomination according to different research teams, tissue or biological fluid sources, extraction and purification, assays, biological properties and chemical and biophysical features. When data is available, comparison with ouabain itself is mentioned. Likewise, their potential action in normal physiology as well as in experimental and human pathology is summarized.
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Affiliation(s)
- G Rodríguez de Lores Arnaiz
- Instituto de Biología Celular y Neurociencias Prof. Eduardo De Robertis, PROBICENE-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Paraguay, Buenos Aires, Argentina.
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Handa RK. Metabolism alters the selectivity of angiotensin-(1-7) receptor ligands for angiotensin receptors. J Am Soc Nephrol 2000; 11:1377-1386. [PMID: 10906151 DOI: 10.1681/asn.v1181377] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The present study examined whether metabolism of the putative angiotensin-(1-7) receptor agonist and antagonist [angiotensin-(1-7) and D-alanine(7) angiotensin-(1-7), respectively] altered their ability to interact with angiotensin AT(1), AT(2), and AT(4) receptor subtypes. Both angiotensin-(1-7) and D-alanine(7) angiotensin-(1-7) competed with low affinity for (125)I-sarcosine(1), isoleucine(8) angiotensin II binding to AT(1) and AT(2) receptors in rat liver and adrenal medulla membranes, respectively, and competed with low affinity for (125)I-angiotensin IV binding to AT(4) receptors in bovine kidney epithelial cell membranes. In vitro renal metabolism of the angiotensin-(1-7) receptor ligands (incubating peptides with rat cortical tissue homogenates) had minimal influence on low-affinity binding to AT(1) and AT(2) receptors, yet caused a significant and dramatic shift toward high-affinity binding for AT(4) receptors. Low-affinity angiotensin II binding to the AT(4) receptor was also shifted toward high-affinity binding following renal metabolism of the peptide. Conversely, angiotensins with high affinity for the AT(4) receptor (e.g., angiotensin IV) were shifted toward low-affinity binding states following peptide metabolism. Incubation of (125)I-angiotensin-(1-7) with rat cortical tissue generated the high-affinity AT(4) receptor ligand (125)I-angiotensin-(3-7), whereas the renal metabolism of (125)I-angiotensin II generated both (125)I-angiotensin-(3-7) and (125)I-angiotensin IV. These results reveal that renal metabolism of angiotensin-(1-7) receptor ligands and angiotensin II yields products that have high affinity for the AT(4) receptor and could potentially contribute to the biologic actions of the parent peptide in the kidney.
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Affiliation(s)
- Rajash K Handa
- Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, College of Veterinary Medicine, Washington State University, Pullman, Washington
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Gironacci MM, Vatta M, Rodriguez-Fermepín M, Fernández BE, Peña C. Angiotensin-(1-7) reduces norepinephrine release through a nitric oxide mechanism in rat hypothalamus. Hypertension 2000; 35:1248-52. [PMID: 10856272 DOI: 10.1161/01.hyp.35.6.1248] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin (Ang)-(1-7) elicits a facilitatory presynaptic effect on peripheral noradrenergic neurotransmission, and because biological responses to the heptapeptide on occasion are tissue specific, the present investigation was undertaken to study its action on noradrenergic neurotransmission at the central level. In rat hypothalamus labeled with [(3)H]-norepinephrine, 100 to 600 nmol/L Ang-(1-7) diminished norepinephrine released by 25 mmol/L KCl. This effect was blocked by the selective angiotensin type 2 receptor antagonist PD 123319 (1 micromol/L) and by the specific Ang-(1-7) receptor antagonist ([D-Ala(7)]Ang-(1-7) (1 micromol/L) but not by losartan (10 nmol/L to 1 micromol/L), a selective angiotensin type 1 receptor antagonist. The inhibitory effect on noradrenergic neurotransmission caused by Ang-(1-7) was prevented by 10 micromol/L N(omega)-nitro-L-arginine methylester, an inhibitor of nitric oxide synthase activity, and was restored by 100 micromol/L L-arginine, precursor of nitric oxide synthesis. Methylene blue (10 micromol/L), an inhibitor of guanylate cyclase considered as the target of nitric oxide action, as well as Hoe 140 (10 micromol/L), a bradykinin B(2)-receptor antagonist, prevented the inhibitory effect of the heptapeptide on neuronal norepinephrine release, whereas no modification was observed in the presence of 0.1 to 10 micromol/L indomethacin, a cyclooxygenase inhibitor. Our results indicate that Ang-(1-7) has a tissue-specific neuromodulatory effect on noradrenergic neurotransmission, being inhibitory at the central nervous system by a nitric oxide-dependent mechanism that involves angiotensin type 2 receptors and local bradykinin production.
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Affiliation(s)
- M M Gironacci
- Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
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López Ordieres MG, Rodríguez de Lores Arnaiz G. Neurotensin inhibits neuronal Na+,K+-ATPase activity through high affinity peptide receptor. Peptides 2000; 21:571-6. [PMID: 10822114 DOI: 10.1016/s0196-9781(00)00183-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neurotensin is a peptide present in mammalian CNS and peripheral tissues, which may play a major role in neurotransmission or neuromodulation, subserving diverse physiological functions. We studied the effect of added neurotensin on ATPase activities in synaptosomal membranes isolated from rat cerebral cortex. Neurotensin at 3 x 10(-8)-3 x 10(-6) M concentration decreased 20-44% Na+,K+-ATPase activity but failed to modify Mg2+-ATPase activity; lower neurotensin concentrations (3 x 10(-14)-3 x 10(-10) M) had no effect on enzyme activities. This inhibitory effect was abolished by neurotensin heating, by enzyme preincubation with neurotensin during periods exceeding 10 min, or by adding 1 x 10(-6) M SR 48692, a high affinity neurotensin receptor antagonist. Levocabastine, which blocks low affinity neurotensin receptor, failed to alter enzyme inhibition by the peptide. It is suggested that the sodium pump may be a target for neurotensin effects at neuronal level involving the participation of high affinity neurotensin receptor.
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Affiliation(s)
- M G López Ordieres
- Instituto de Biología Celular y Neurociencias Prof. Eduardo De Robertis, Facultad de Medicina, PROBICENE-CONICET and Cátedra de Farmacología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Paraguay 2155, 1121, Buenos Aires, Argentina
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Gironacci MM, Coba MP, Peña C. Angiotensin-(1-7) binds at the type 1 angiotensin II receptors in rat renal cortex. REGULATORY PEPTIDES 1999; 84:51-4. [PMID: 10535408 DOI: 10.1016/s0167-0115(99)00067-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Significant angiotensin (Ang) (1-7) production occurs in kidney and effects on renal function have been observed. The present study was undertaken to investigate binding characteristics of the heptapeptide to Ang II receptors present in rat renal cortex. [125I]-Ang II binding to rat glomeruli membranes was analyzed in the presence of increasing concentrations of Ang II, Ang-(1-7), DUP 753 and PD 123319. Linearity of the Scatchard plot of the [125I]-Ang II specific binding to rat glomeruli membranes indicated a single population of receptors, with a Kd value of 0.7 +/- 0.1 nM and a Bmax of 198 +/- 0.04 fmol/mg protein. DUP 753, an specific AT1 receptor antagonist, totally displaced the specific binding of [125I]-radiolabelled hormone with a Ki of 15.8 +/- 0.9 nM, while no changes were observed in the presence of the selective AT2 receptor antagonist, PD 123319. The specific [125I]-Ang II binding to rat glomerular membranes was displaced by Ang-(1-7) with high affinity (Ki = 8.0 +/- 3.2 nM). We conclude that radioligand binding assays in the presence of selective Ang II antagonists DUP 753 and PD 123319 suggest the unique presence of AT1, receptors in rat glomeruli and a possible role in the control of the biological renal effects of Ang-(1-7).
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Affiliation(s)
- M M Gironacci
- Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
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