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Ogonowski N, Rukavina Mikusic NL, Kouyoumdzian NM, Choi MR, Fellet A, Balaszczuk AM, Celuch SM. Cardiotoxic Effects of the Antineoplastic Doxorubicin in a Model of Metabolic Syndrome: Oxidative Stress and Transporter Expression in the Heart. J Cardiovasc Pharmacol 2021; 78:784-791. [PMID: 34524257 DOI: 10.1097/fjc.0000000000001137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/18/2021] [Indexed: 12/22/2022]
Abstract
ABSTRACT The aim of the present work was to examine whether metabolic syndrome-like conditions in rats with fructose (F) overload modify the cardiotoxic effects induced by doxorubicin (DOX) and whether the treatment altered the expression of P-gp, breast cancer resistance protein, and organic cation/carnitine transporters in the heart. Male Sprague-Dawley rats received either tap water (control group [C]; n = 16) or water with F 10% wt/vol (n = 16) during 8 weeks. Three days before being killed, the animals received a single dose of DOX (6 mg/kg, ip, md) (C-DOX and F-DOX groups) or vehicle (VEH; ISS 1 mL/kg BW; ip) (C-VEH and F-VEH groups) (n = 8 per group). F overload enhanced thiobarbituric acid-reactive substance levels in the left ventricle, and DOX injection further increased those values. DOX did not alter thiobarbituric acid-reactive substance production in C animals. DOX caused a decrease of 30% in the ejection fraction and a nearly 40% reduction in the fractional shortening in F animals, but not in C rats. Cardiac tissue levels of P-gp decreased by about 30% in F rats compared with the C groups. DOX did not modify cardiac P-gp expression. Breast cancer resistance protein and organic cation/carnitine transporter (OCTN 1/2/3) protein levels did not change with either F or DOX. It is suggested that DOX could cause greater cardiotoxicity in rats receiving F, probably due to enhanced cardiac lipid peroxidation and lower expression of cardiac P-gp. These results support the hypothesis that the cardiotoxicity of DOX could be increased under metabolic syndrome-like conditions or in other health disorders that involve cardiovascular risk factors.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 2/metabolism
- Animals
- Antibiotics, Antineoplastic
- Cardiotoxicity
- Disease Models, Animal
- Doxorubicin
- Heart Diseases/chemically induced
- Heart Diseases/metabolism
- Heart Diseases/pathology
- Heart Diseases/physiopathology
- Lipid Peroxidation
- Male
- Metabolic Syndrome/complications
- Metabolic Syndrome/metabolism
- Myocardium/metabolism
- Myocardium/pathology
- Organic Cation Transport Proteins/genetics
- Organic Cation Transport Proteins/metabolism
- Oxidative Stress
- Rats, Sprague-Dawley
- Ventricular Function, Left/drug effects
- Rats
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Affiliation(s)
- Natalia Ogonowski
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Fisiología, Instituto de Química y Metabolismo del Fármaco, CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Natalia Lucía Rukavina Mikusic
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Anatomía e Histología, Ciudad Autónoma de Buenos Aires, Argentina
| | - Nicolás Martín Kouyoumdzian
- Universidad de Buenos Aires, Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), CONICET, Ciudad Autónoma de Buenos Aires, Argentina; and
| | - Marcelo Roberto Choi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Anatomía e Histología, Ciudad Autónoma de Buenos Aires, Argentina
- Universidad de Buenos Aires, Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), CONICET, Ciudad Autónoma de Buenos Aires, Argentina; and
| | - Andrea Fellet
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Fisiología, Instituto de Química y Metabolismo del Fármaco, CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Ana María Balaszczuk
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Fisiología, Instituto de Química y Metabolismo del Fármaco, CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Stella Maris Celuch
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas, CONICET, Ciudad Autónoma de Buenos Aires, Argentina
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Feitosa LADS, Carvalho JDS, Dantas CO, de Souza DS, de Vasconcelos CML, Miguel-Dos-Santos R, Lauton-Santos S, Quíntans-Júnior LJ, Santos MRV, de Santana-Filho VJ, Barreto AS. Resistance training improves cardiac function and cardiovascular autonomic control in doxorubicin-induced cardiotoxicity. Cardiovasc Toxicol 2021; 21:365-374. [PMID: 33387253 DOI: 10.1007/s12012-020-09627-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/14/2020] [Indexed: 02/02/2023]
Abstract
Doxorubicin (DOX) is an anticancer chemotherapy drug that is widely used in clinical practice. It is well documented that DOX impairs baroreflex responsiveness and left ventricular function and enhances sympathetic activity, cardiac sympathetic afferent reflexes and oxidative stress, which contribute to hemodynamic deterioration. Because resistance training (RT)-induced cardioprotection has been observed in other animal models, the objective of this study was to assess the effects of RT during DOX treatment on hemodynamics, arterial baroreflex, cardiac autonomic tone, left ventricular function and oxidative stress in rats with DOX-induced cardiotoxicity. Male Wistar rats were submitted to a RT protocol (3 sets of 10 repetitions, 40% of one-repetition maximum (1RM) of intensity, 3 times per week, for 8 weeks). The rats were separated into 3 groups: sedentary control, DOX sedentary (2.5 mg/kg of DOX intraperitoneal injection, once a week, for 6 weeks) and DOX + RT. After training or time control, the animals were anesthetized and 2 catheters were implanted for hemodynamic, arterial baroreflex and cardiac autonomic tone. Another group of animals was used to evaluate left ventricular function. We found that RT in DOX-treated rats decreased diastolic arterial pressure, heart rate, sympathetic tone and oxidative stress. In addition, RT increased arterial baroreflex sensitivity, vagal tone and left ventricular developed pressure in rats with DOX-induced cardiotoxicity. In summary, RT is a useful non-pharmacological strategy to attenuate DOX-induced cardiotoxicity.
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Affiliation(s)
| | | | - Cácia Oliveira Dantas
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
| | - Diego Santos de Souza
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
| | | | - Rodrigo Miguel-Dos-Santos
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
- Cardiac Exercise Research Group, Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Sandra Lauton-Santos
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
| | | | | | | | - André Sales Barreto
- Department of Health Education, Federal University of Sergipe, Lagarto, Sergipe, Brazil
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Brooks VL, Fu Q, Shi Z, Heesch CM. Adaptations in autonomic nervous system regulation in normal and hypertensive pregnancy. HANDBOOK OF CLINICAL NEUROLOGY 2020; 171:57-84. [PMID: 32736759 DOI: 10.1016/b978-0-444-64239-4.00003-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
There is an increase in basal sympathetic nerve activity (SNA) during normal pregnancy; this counteracts profound primary vasodilation. However, pregnancy also impairs baroreflex control of heart rate and SNA, contributing to increased mortality secondary to peripartum hemorrhage. Pregnancy-induced hypertensive disorders evoke even greater elevations in SNA, which likely contribute to the hypertension. Information concerning mechanisms is limited. In normal pregnancy, increased angiotensin II acts centrally to support elevated SNA. Hypothalamic sites, including the subfornical organ, paraventricular nucleus, and arcuate nucleus, are likely (but unproven) targets. Moreover, no definitive mechanisms for exaggerated sympathoexcitation in hypertensive pregnancy have been identified. In addition, normal pregnancy increases gamma aminobutyric acid inhibition of the rostral ventrolateral medulla (RVLM), a key brainstem site that transmits excitatory inputs to spinal sympathetic preganglionic neurons. Accumulated evidence supports a major role for locally increased production and actions of the neurosteroid allopregnanolone as one mechanism. A consequence is suppression of baroreflex function, but increased basal SNA indicates that excitatory influences predominate in the RVLM. However, many questions remain regarding other sites and factors that support increased SNA during normal pregnancy and, more importantly, the mechanisms underlying excessive sympathoexcitation in life-threatening hypertensive pregnancy disorders such as preeclampsia.
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Affiliation(s)
- Virginia L Brooks
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR, United States.
| | - Qi Fu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, United States; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Zhigang Shi
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR, United States
| | - Cheryl M Heesch
- Department of Biomedical Sciences and Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, United States
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Becker BK, Feagans AC, Chen D, Kasztan M, Jin C, Speed JS, Pollock JS, Pollock DM. Renal denervation attenuates hypertension but not salt sensitivity in ET B receptor-deficient rats. Am J Physiol Regul Integr Comp Physiol 2017; 313:R425-R437. [PMID: 28701323 DOI: 10.1152/ajpregu.00174.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/16/2017] [Accepted: 07/06/2017] [Indexed: 02/07/2023]
Abstract
Hypertension is a prevalent pathology that increases risk for numerous cardiovascular diseases. Because the etiology of hypertension varies across patients, specific and effective therapeutic approaches are needed. The role of renal sympathetic nerves is established in numerous forms of hypertension, but their contribution to salt sensitivity and interaction with factors such as endothelin-1 are poorly understood. Rats deficient of functional ETB receptors (ETB-def) on all tissues except sympathetic nerves are hypertensive and exhibit salt-sensitive increases in blood pressure. We hypothesized that renal sympathetic nerves contribute to hypertension and salt sensitivity in ETB-def rats. The hypothesis was tested through bilateral renal sympathetic nerve denervation and measuring blood pressure during normal salt (0.49% NaCl) and high-salt (4.0% NaCl) diets. Denervation reduced mean arterial pressure in ETB-def rats compared with sham-operated controls by 12 ± 3 (SE) mmHg; however, denervation did not affect the increase in blood pressure after 2 wk of high-salt diet (+19 ± 3 vs. +16 ± 3 mmHg relative to normal salt diet; denervated vs. sham, respectively). Denervation reduced cardiac sympathetic-to-parasympathetic tone [low frequency-high frequency (LF/HF)] during normal salt diet and vasomotor LF/HF tone during high-salt diet in ETB-def rats. We conclude that the renal sympathetic nerves contribute to the hypertension but not to salt sensitivity of ETB-def rats.
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Affiliation(s)
- Bryan K Becker
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Amanda C Feagans
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Daian Chen
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Malgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Joshua S Speed
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jennifer S Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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Cardioprotective Effect of Phenytoin on Doxorubicin-induced Cardiac Toxicity in a Rat Model. J Cardiovasc Pharmacol 2016; 67:237-45. [DOI: 10.1097/fjc.0000000000000339] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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6
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Pinkham MI, Whalley GA, Guild SJ, Malpas SC, Barrett CJ. Arterial baroreceptor reflex control of renal sympathetic nerve activity following chronic myocardial infarction in male, female, and ovariectomized female rats. Am J Physiol Regul Integr Comp Physiol 2015; 309:R169-78. [PMID: 25994953 DOI: 10.1152/ajpregu.00026.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There is controversy regarding whether the arterial baroreflex control of renal sympathetic nerve activity (SNA) in heart failure is altered. We investigated the impact of sex and ovarian hormones on changes in the arterial baroreflex control of renal SNA following a chronic myocardial infarction (MI). Renal SNA and arterial pressure were recorded in chloralose-urethane anesthetized male, female, and ovariectomized female (OVX) Wistar rats 6-7 wk postsham or MI surgery. Animals were grouped according to MI size (sham, small and large MI). Ovary-intact females had a lower mortality rate post-MI (24%) compared with both males (38%) and OVX (50%) (P < 0.05). Males and OVX with large MI, but not small MI, displayed an impaired ability of the arterial baroreflex to inhibit renal SNA. As a result, the male large MI group (49 ± 6 vs. 84 ± 5% in male sham group) and OVX large MI group (37 ± 3 vs. 75 ± 5% in OVX sham group) displayed significantly reduced arterial baroreflex range of control of normalized renal SNA (P < 0.05). In ovary-intact females, arterial baroreflex control of normalized renal SNA was unchanged regardless of MI size. In males and OVX there was a significant, positive correlation between left ventricle (LV) ejection fraction and arterial baroreflex range of control of normalized renal SNA, but not absolute renal SNA, that was not evident in ovary-intact females. The current findings demonstrate that the arterial baroreflex control of renal SNA post-MI is preserved in ovary-intact females, and the state of left ventricular dysfunction significantly impacts on the changes in the arterial baroreflex post-MI.
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Ramchandra R, Barrett CJ. Regulation of the renal sympathetic nerves in heart failure. Front Physiol 2015; 6:238. [PMID: 26388778 PMCID: PMC4556040 DOI: 10.3389/fphys.2015.00238] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 08/07/2015] [Indexed: 12/20/2022] Open
Abstract
Heart failure (HF) is a serious debilitating condition with poor survival rates and an increasing level of prevalence. HF is associated with an increase in renal norepinephrine (NE) spillover, which is an independent predictor of mortality in HF patients. The excessive sympatho-excitation that is a hallmark of HF has long-term effects that contribute to disease progression. An increase in directly recorded renal sympathetic nerve activity (RSNA) has also been recorded in animal models of HF. This review will focus on the mechanisms controlling sympathetic nerve activity (SNA) to the kidney during normal conditions and alterations in these mechanisms during HF. In particular the roles of afferent reflexes and central mechanisms will be discussed.
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Affiliation(s)
- Rohit Ramchandra
- Department of Physiology, The University of Auckland Auckland, New Zealand
| | - Carolyn J Barrett
- Department of Physiology, The University of Auckland Auckland, New Zealand
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Colak MC, Parlakpinar H, Tasdemir S, Samdanci E, Kose E, Polat A, Sarihan E, Acet A. Therapeutic effects of ivabradine on hemodynamic parameters and cardiotoxicity induced by doxorubicin treatment in rat. Hum Exp Toxicol 2012; 31:945-54. [DOI: 10.1177/0960327112438288] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The aim of this study was to investigate the possible effects of ivabradine against doxorubicin (DOX)-induced cardiotoxicity in rats using hemodynamic parameters (electrocardiogram, heart rate (HR), and blood pressure), biochemical markers of oxidative stress, lactate dehydrogenase, aspartate transaminase, creatine kinase-MB, and histopathological analyses both in serum and tissue specimens. A total of 28 female rats were randomly assigned to 4 groups: (a) control ( n = 6 rats), (b) DOX group ( n = 7 rats), (c) DOX + ivabradine–treated group ( n = 8 rats), and (d) ivabradine group ( n = 7 rats). When the means of the four groups were compared, there was only a significant difference in the level of HR ( p < 0.05). DOX treatment caused more HR elevation when compared to the control group, whereas ivabradine application after DOX treatment significantly reduced HR levels. Cardiomyocytes were revealed as normal histology in the light of both hematoxylin and eosin staining and immunostaining methods (caspase-3 and bcl-2) in all groups. The present study reported the therapeutic effects of ivabradine against DOX-induced cardiotoxicity accompanied by the hemodynamic and biochemical parameters.
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Affiliation(s)
- MC Colak
- Department of Cardiovascular Surgery, Inonu University, Malatya, Turkey
| | - H Parlakpinar
- Department of Pharmacology, Inonu University, Malatya, Turkey
| | - S Tasdemir
- Department of Pharmacology, Inonu University, Malatya, Turkey
| | - E Samdanci
- Department of Pathology, Inonu University, Malatya, Turkey
| | - E Kose
- Department of Anatomy, Inonu University, Malatya, Turkey
| | - A Polat
- Department of Physiology, Inonu University, Malatya, Turkey
| | - E Sarihan
- Department of Emergency Medicine, Inonu University, Malatya, Turkey
| | - A Acet
- Department of Pharmacology, Inonu University, Malatya, Turkey
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Rossi NF, Zhang F, Chen H. Effect of chronic central endothelin-1 on hemodynamics and plasma vasopressin in conscious rats. Neurol Res 2011; 33:169-75. [PMID: 21801591 DOI: 10.1179/016164111x12881719352336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES These studies were designed to test whether chronic central administration of endothelin-1 induces changes in systemic hemodynamics and plasma vasopressin similar to those observed with acute microinjections of endothelin-1. METHODS Sprague Dawley rats underwent sham denervation or sinoaortic denervation. Three days later, baseline mean arterial blood pressure, heart rate, and vasopressin were assessed in conscious rats. Then, a cannula was stereotaxically inserted into the lateral ventricle and attached to an osmotic minipump that delivered one of the following: (i) artificial cerebrospinal fluid; (ii) endothelin-1, 10 pmol/hour; (iii) BQ-123, 400 pmol/hour; or (iv) endothelin-1+BQ-123. Mean arterial blood pressure and heart rate were monitored daily and blood was obtained for plasma vasopressin on days 3 and 9. On day 10, the rats were euthanized, the hypothalami were removed, and vasopressin messenger ribonucleic acid content was assessed. RESULTS The pressor effect of intracerebroventricular endothelin-1 was similar in intact and sinoaortic denervation rats and was prevented by endothelin receptor A antagonism with BQ-123. Administration of BQ-123 alone resulted in a depressor and bradycardia in sinoaortically denervated rats. Chronic endothelin-1 administration did not change plasma vasopressin but resulted in a significant decrease in hypothalamic vasopressin messenger ribonucleic acid levels, which was reversed by endothelin receptor A inhibition. DISCUSSION Although the pressor effect of chronic central endothelin-1 is similar to that reported with acute endothelin-1, plasma vasopressin levels do not increase, at least in part, due to downregulation of hypothalamic vasopressin gene expression. Sinoaortic denervation increases endogenous central endothelin receptor A tone. Furthermore, these observations confirm that the pressor effect of central endothelin-1 is not mediated by plasma vasopressin.
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Affiliation(s)
- Noreen F Rossi
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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Kohan DE, Rossi NF, Inscho EW, Pollock DM. Regulation of blood pressure and salt homeostasis by endothelin. Physiol Rev 2011; 91:1-77. [PMID: 21248162 DOI: 10.1152/physrev.00060.2009] [Citation(s) in RCA: 291] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Endothelin (ET) peptides and their receptors are intimately involved in the physiological control of systemic blood pressure and body Na homeostasis, exerting these effects through alterations in a host of circulating and local factors. Hormonal systems affected by ET include natriuretic peptides, aldosterone, catecholamines, and angiotensin. ET also directly regulates cardiac output, central and peripheral nervous system activity, renal Na and water excretion, systemic vascular resistance, and venous capacitance. ET regulation of these systems is often complex, sometimes involving opposing actions depending on which receptor isoform is activated, which cells are affected, and what other prevailing factors exist. A detailed understanding of this system is important; disordered regulation of the ET system is strongly associated with hypertension and dysregulated extracellular fluid volume homeostasis. In addition, ET receptor antagonists are being increasingly used for the treatment of a variety of diseases; while demonstrating benefit, these agents also have adverse effects on fluid retention that may substantially limit their clinical utility. This review provides a detailed analysis of how the ET system is involved in the control of blood pressure and Na homeostasis, focusing primarily on physiological regulation with some discussion of the role of the ET system in hypertension.
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Affiliation(s)
- Donald E Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
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Opposing actions of endothelin-1 on glutamatergic transmission onto vasopressin and oxytocin neurons in the supraoptic nucleus. J Neurosci 2011; 30:16855-63. [PMID: 21159956 DOI: 10.1523/jneurosci.5079-10.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Endothelin (ET-1) given centrally has many reported actions on hormonal and autonomic outputs from the CNS. However, it is unclear whether these effects are due to local ischemia via its vasoconstrictor properties or to a direct neuromodulatory action. ET-1 stimulates the release of oxytocin (OT) and vasopressin (VP) from supraoptic magnocellular (MNCs) neurons in vivo; therefore, we asked whether ET-1 modulates the excitatory inputs onto MNCs that are critical in sculpting the activity of these neurons. To investigate whether ET-1 modulates excitatory synaptic transmission, we obtained whole-cell recordings and analyzed quantal glutamate release onto MNCs in the supraoptic nucleus (SON). Neurons identified as VP-containing neurosecretory cells displayed a decrease in quantal frequency in response to ET-1 (10-100 pm). This decrease was mediated by ET(A) receptor activation and production of a retrograde messenger that targets presynaptic cannabinoid-1 receptors. In contrast, neurons identified as OT-containing MNCs displayed a transient increase in quantal glutamate release in response to ET-1 application via ET(B) receptor activation. Application of TTX to block action potential-dependent glutamate release inhibited the excitatory action of ET-1 in OT neurons. There were no changes in quantal amplitude in either MNC type, suggesting that the effects of ET-1 were via presynaptic mechanisms. A gliotransmitter does not appear to be involved as ET-1 failed to elevate astrocytic calcium in the SON. Our results demonstrate that ET-1 differentially modulates glutamate release onto VP- versus OT-containing MNCs, thus implicating it in the selective regulation of neuroendocrine output from the SON.
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Hazari MS, Haykal-Coates N, Winsett DW, Costa DL, Farraj AK. Continuous Electrocardiogram Reveals Differences in the Short-Term Cardiotoxic Response of Wistar-Kyoto and Spontaneously Hypertensive Rats to Doxorubicin. Toxicol Sci 2009; 110:224-34. [DOI: 10.1093/toxsci/kfp092] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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