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Becker BK, Grady CM, Markl AE, Torres Rodriguez AA, Pollock DM. Elevated renal afferent nerve activity in a rat model of endothelin B receptor deficiency. Am J Physiol Renal Physiol 2023; 325:F235-F247. [PMID: 37348026 PMCID: PMC10396274 DOI: 10.1152/ajprenal.00064.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/13/2023] [Accepted: 06/21/2023] [Indexed: 06/24/2023] Open
Abstract
Renal nerves have been an attractive target for interventions aimed at lowering blood pressure; however, the specific roles of renal afferent (sensory) versus efferent sympathetic nerves in mediating hypertension are poorly characterized. A number of studies have suggested that a sympathoexcitatory signal conveyed by renal afferents elicits increases in blood pressure, whereas other studies identified sympathoinhibitory afferent pathways. These sympathoinhibitory pathways have been identified as protective against salt-sensitive increases in blood pressure through endothelin B (ETB) receptor activation. We hypothesized that ETB-deficient (ETB-def) rats, which are devoid of functional ETB receptors except in adrenergic tissues, lack appropriate sympathoinhibition and have lower renal afferent nerve activity following a high-salt diet compared with transgenic controls. We found that isolated renal pelvises from high salt-fed ETB-def animals lack a response to a physiological stimulus, prostaglandin E2, compared with transgenic controls but respond equally to a noxious stimulus, capsaicin. Surprisingly, we observed elevated renal afferent nerve activity in intact ETB-def rats compared with transgenic controls under both normal- and high-salt diets. ETB-def rats have been previously shown to have heightened global sympathetic tone, and we also observed higher total renal sympathetic nerve activity in ETB-def rats compared with transgenic controls under both normal- and high-salt diets. These data indicate that ETB receptors are integral mediators of the sympathoinhibitory renal afferent reflex (renorenal reflex), and, in a genetic rat model of ETB deficiency, the preponderance of sympathoexcitatory renal afferent nerve activity prevails and may contribute to hypertension.NEW & NOTEWORTHY Here, we found that endothelin B receptors are an important contributor to renal afferent nerve responsiveness to a high-salt diet. Rats lacking endothelin B receptors have increased afferent nerve activity that is not responsive to a high-salt diet.
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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, United States
| | - Caroline M Grady
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Alexa E Markl
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Alfredo A Torres Rodriguez
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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2
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Osipov A, Utkin Y. What Are the Neurotoxins in Hemotoxic Snake Venoms? Int J Mol Sci 2023; 24:ijms24032919. [PMID: 36769242 PMCID: PMC9917609 DOI: 10.3390/ijms24032919] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/10/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Snake venoms as tools for hunting are primarily aimed at the most vital systems of the prey, especially the nervous and circulatory systems. In general, snakes of the Elapidae family produce neurotoxic venoms comprising of toxins targeting the nervous system, while snakes of the Viperidae family and most rear-fanged snakes produce hemotoxic venoms directed mainly on blood coagulation. However, it is not all so clear. Some bites by viperids results in neurotoxic signs and it is now known that hemotoxic venoms do contain neurotoxic components. For example, viperid phospholipases A2 may manifest pre- or/and postsynaptic activity and be involved in pain and analgesia. There are other neurotoxins belonging to diverse families ranging from large multi-subunit proteins (e.g., C-type lectin-like proteins) to short peptide neurotoxins (e.g., waglerins and azemiopsin), which are found in hemotoxic venoms. Other neurotoxins from hemotoxic venoms include baptides, crotamine, cysteine-rich secretory proteins, Kunitz-type protease inhibitors, sarafotoxins and three-finger toxins. Some of these toxins exhibit postsynaptic activity, while others affect the functioning of voltage-dependent ion channels. This review represents the first attempt to systematize data on the neurotoxins from "non-neurotoxic" snake venom. The structural and functional characteristic of these neurotoxins affecting diverse targets in the nervous system are considered.
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Becker BK, Johnston JG, Young CM, Torres Rodriguez AA, Jin C, Pollock DM. Endothelin B receptors impair baroreflex function and increase blood pressure variability during high salt diet. Auton Neurosci 2021; 232:102796. [PMID: 33798837 PMCID: PMC8040376 DOI: 10.1016/j.autneu.2021.102796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 10/21/2022]
Abstract
Baroreflex function is an integral component maintaining consistent blood pressure. Hypertension is often associated with baroreflex dysfunction, and environmental risk factors such as high salt diet exacerbate hypertension in subjects with baroreflex dysfunction. However, the interactions between high salt diet, baroreflex dysfunction, and hypertension are incompletely understood. The endothelin system is another potent mediator of blood pressure control especially in response to a high salt diet. We hypothesized that the endothelin B (ETB) receptor activation on adrenergic nerves decreases baroreflex sensitivity. We utilized male ETB receptor deficient (ETB-def) rats that express functional ETB receptors only on adrenergic nerves and transgenic (TG) controls to evaluate baroreflex function during normal (0.49% NaCl) and high (4.0% NaCl) salt diets. In conscious rats equipped with telemetry, ETB-def rats had an increased lability of systolic blood pressure (SBP) compared to TG controls as indicated by higher standard deviation (SD) of SBP under both normal (10.2 ± 0.6 vs. 12.4 ± 0.9 mmHg, respectively, p = 0.0001) and high (11.7 ± 0.6 vs. 16.1 ± 1.0 mmHg, p = 0.0001) salt diets. In anesthetized preparations, ETB-def rats displayed reduced heart rate (p genotype = 0.0167) and renal sympathetic nerve (p genotype = 0.0022) baroreflex sensitivity. We then gave male Sprague-Dawley rats the selective ETB receptor antagonist, A-192621 (10 mg/kg/day), to block ETB receptors. Following ETB receptor antagonism, even though SBP increased (131 ± 7 before vs. 152 ± 8 mmHg after, p < 0.0001), the lability (standard deviation) of SBP decreased (9.3 ± 2.0 vs. 7.1 ± 1.1 mmHg, p = 0.0155). These data support our hypothesis that ETB receptors on adrenergic nerves contribute to baroreflex dysfunction.
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Affiliation(s)
- Bryan K Becker
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America.
| | - Jermaine G Johnston
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Carolyn M Young
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Alfredo A Torres Rodriguez
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
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4
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Jenkins HN, Rivera-Gonzalez O, Gibert Y, Speed JS. Endothelin-1 in the pathophysiology of obesity and insulin resistance. Obes Rev 2020; 21:e13086. [PMID: 32627269 PMCID: PMC7669671 DOI: 10.1111/obr.13086] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/07/2020] [Accepted: 05/23/2020] [Indexed: 12/29/2022]
Abstract
The association between plasma endothelin-1 (ET-1) and obesity has been documented for decades, yet the contribution of ET-1 to risk factors associated with obesity is not fully understood. In 1994, one of first papers to document this association also noted a positive correlation between plasma insulin and ET-1, suggesting a potential contribution of ET-1 to the development of insulin resistance. Both endogenous receptors for ET-1, ETA and ETB are present in all insulin-sensitive tissues including adipose, liver and muscle, and ET-1 actions within these tissues suggest that ET-1 may be playing a role in the pathogenesis of insulin resistance. Further, antagonists for ET-1 receptors are clinically approved making these sites attractive therapeutic targets. This review focuses on known mechanisms through which ET-1 affects plasma lipid profiles and insulin signalling in these metabolically important tissues and also identifies gaps in our understanding of ET-1 in obesity-related pathophysiology.
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Affiliation(s)
- Haley N. Jenkins
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39047
| | - Osvaldo Rivera-Gonzalez
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39047
| | - Yann Gibert
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, MS 39047
| | - Joshua S. Speed
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39047
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5
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Borovac JA, D'Amario D, Bozic J, Glavas D. Sympathetic nervous system activation and heart failure: Current state of evidence and the pathophysiology in the light of novel biomarkers. World J Cardiol 2020; 12:373-408. [PMID: 32879702 PMCID: PMC7439452 DOI: 10.4330/wjc.v12.i8.373] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/19/2020] [Accepted: 07/19/2020] [Indexed: 02/06/2023] Open
Abstract
Heart failure (HF) is a complex clinical syndrome characterized by the activation of at least several neurohumoral pathways that have a common role in maintaining cardiac output and adequate perfusion pressure of target organs and tissues. The sympathetic nervous system (SNS) is upregulated in HF as evident in dysfunctional baroreceptor and chemoreceptor reflexes, circulating and neuronal catecholamine spillover, attenuated parasympathetic response, and augmented sympathetic outflow to the heart, kidneys and skeletal muscles. When these sympathoexcitatory effects on the cardiovascular system are sustained chronically they initiate the vicious circle of HF progression and become associated with cardiomyocyte apoptosis, maladaptive ventricular and vascular remodeling, arrhythmogenesis, and poor prognosis in patients with HF. These detrimental effects of SNS activity on outcomes in HF warrant adequate diagnostic and treatment modalities. Therefore, this review summarizes basic physiological concepts about the interaction of SNS with the cardiovascular system and highlights key pathophysiological mechanisms of SNS derangement in HF. Finally, special emphasis in this review is placed on the integrative and up-to-date overview of diagnostic modalities such as SNS imaging methods and novel laboratory biomarkers that could aid in the assessment of the degree of SNS activation and provide reliable prognostic information among patients with HF.
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Affiliation(s)
- Josip Anđelo Borovac
- Department of Pathophysiology, University of Split School of Medicine, Split 21000, Croatia
- Working Group on Heart Failure of Croatian Cardiac Society, Zagreb 10000, Croatia
| | - Domenico D'Amario
- Department of Cardiovascular and Thoracic Sciences, IRCCS Fondazione Policlinico A. Gemelli, Universita Cattolica Sacro Cuore, Rome 00168, Italy
| | - Josko Bozic
- Department of Pathophysiology, University of Split School of Medicine, Split 21000, Croatia
| | - Duska Glavas
- Working Group on Heart Failure of Croatian Cardiac Society, Zagreb 10000, Croatia
- Clinic for Cardiovascular Diseases, University Hospital of Split, Split 21000, Croatia
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6
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Greaney JL, Surachman A, Saunders EFH, Alexander LM, Almeida DM. Greater Daily Psychosocial Stress Exposure is Associated With Increased Norepinephrine-Induced Vasoconstriction in Young Adults. J Am Heart Assoc 2020; 9:e015697. [PMID: 32340506 PMCID: PMC7428556 DOI: 10.1161/jaha.119.015697] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background Epidemiological data suggest a link between psychological stress and increased cardiovascular disease risk; however, the underlying mechanisms remain incompletely understood. The purpose of this investigation was to directly examine the influence of daily psychosocial stress on microvascular adrenergic vasoconstrictor responsiveness in healthy adults. We hypothesized increased daily psychosocial stress would be positively related to increased norepinephrine-induced vasoconstriction. Methods and Results Eighteen healthy adults (19-36 years; 10 women) completed a daily psychosocial experiences telephone interview for 8 consecutive evenings in order to document their exposure and emotional responsiveness to common stressors (eg, arguments, work stress) over the preceding 24 hrs. On the last interview day, red cell flux (laser Doppler flowmetry) was measured during graded intradermal microdialysis perfusion of norepinephrine (10-12 to 10-2 mol/L) and expressed as a percentage of baseline vascular conductance. Exogenous norepinephrine elicited progressive and robust vasoconstriction in all individuals (maximal vasoconstriction: 71±4%base; cumulative vasoconstriction [area under the curve]: 118±102 arbitrary units). Participants experienced a stressor on 51±5% of days and a total of 5.2±0.9 stressors over the 8-day time frame. Increased daily frequency of stressor exposure was positively related to both maximal (R2=0.26; P=0.03) and cumulative (R2=0.31; P=0.02) vasoconstrictor responsiveness. Likewise, the total number of stressors was associated with increased maximal (R2=0.40; P<0.01) and cumulative (R2=0.27; P=0.03) norepinephrine-induced vasoconstriction. Neither stressor severity nor stress-related emotions were related to vasoconstrictor responsiveness. Conclusions Collectively, these data suggest that daily psychosocial stressor exposure by itself is sufficient to adversely influence microvascular vasoconstrictor function, regardless of the perceived severity or emotional consequences of the stressor exposure.
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Affiliation(s)
- Jody L Greaney
- Noll Laboratory Department of Kinesiology The Pennsylvania State University University Park PA.,Department of Kinesiology The University of Texas at Arlington Arlington TX
| | - Agus Surachman
- Department of Human Development and Family Studies The Pennsylvania State University University Park PA.,Center for Healthy Aging The Pennsylvania State University University Park PA
| | | | - Lacy M Alexander
- Noll Laboratory Department of Kinesiology The Pennsylvania State University University Park PA.,Center for Healthy Aging The Pennsylvania State University University Park PA
| | - David M Almeida
- Department of Human Development and Family Studies The Pennsylvania State University University Park PA.,Center for Healthy Aging The Pennsylvania State University University Park PA
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7
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Spradley FT. Sympathetic nervous system control of vascular function and blood pressure during pregnancy and preeclampsia. J Hypertens 2019; 37:476-487. [PMID: 30160658 PMCID: PMC6355368 DOI: 10.1097/hjh.0000000000001901] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
: Proper vascular tone and blood pressure regulation during pregnancy are important for immediate and long-term cardiovascular health of the mother and her offspring. Preeclampsia is clinically defined as new-onset maternal hypertension accompanied by cardiovascular, renal, and/or neural abnormalities presenting in the second half of pregnancy. There is strong evidence to support that preeclampsia is mediated by attenuations in uteroplacental vascular remodeling and increases in vasoconstriction with subsequent placental ischemia/reperfusion-induced release of hypertensive substances into the maternal circulation. These include antiangiogenic and pro-inflammatory factors. There is also evidence implicating increased sympathetic nervous system activity (SNA) in this maternal disorder, but this mostly includes data correlating severity of disease with catecholamine levels and elevated muscle SNA. These measurements have not confirmed a causative role for SNA in the pathogenesis of preeclampsia. Therefore, studies are needed to provide a comprehensive understanding of SNA and its control of vascular function and blood pressure regulation during normal pregnancy in order to set the stage for exploring the mechanisms mediating the exaggerated SNA and signaling during preeclampsia. This review examines the role of SNA in control of uteroplacental vascular tone and blood pressure regulation during normal pregnancy. Furthermore, it is proposed that over-activation of the SNA contributes to altered uteroplacental vascular tone and perfusion leading to placental ischemic events and modulates the systemic vasoconstriction and hypertensive responses to soluble placenta ischemic factors. Recognizing the integrative role and importance of SNA in the pathophysiology of preeclampsia will advance our understanding of this maternal disorder.
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Affiliation(s)
- Frank T Spradley
- Department of Surgery, The University of Mississippi Medical Center, Jackson, Mississippi, USA
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8
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Fox BM, Becker BK, Loria AS, Hyndman KA, Jin C, Clark H, Johns R, Yanagisawa M, Pollock DM, Pollock JS. Acute Pressor Response to Psychosocial Stress Is Dependent on Endothelium-Derived Endothelin-1. J Am Heart Assoc 2018; 7:JAHA.117.007863. [PMID: 29453306 PMCID: PMC5850198 DOI: 10.1161/jaha.117.007863] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background Acute psychosocial stress provokes increases in circulating endothelin‐1 (ET‐1) levels in humans and animal models. However, key questions about the physiological function and cellular source of stress‐induced ET‐1 remain unanswered. We hypothesized that endothelium‐derived ET‐1 contributes to the acute pressor response to stress via activation of the endothelin A receptor. Methods and Results Adult male vascular endothelium‐specific ET‐1 knockout mice and control mice that were homozygous for the floxed allele were exposed to acute psychosocial stress in the form of cage switch stress (CSS), with blood pressure measured by telemetry. An acute pressor response was elicited by CSS in both genotypes; however, this response was significantly blunted in vascular endothelium‐specific ET‐1 knockout mice compared with control mice that were homozygous for the floxed allele. In mice pretreated for 3 days with the endothelin A antagonist, ABT‐627, or the dual endothelin A/B receptor antagonist, A‐182086, the pressor response to CSS was similar between genotypes. CSS significantly increased plasma ET‐1 levels in control mice that were homozygous for the floxed allele. CSS failed to elicit an increase in plasma ET‐1 in vascular endothelium‐specific ET‐1 knockout mice. Telemetry frequency domain analyses suggested similar autonomic responses to stress between genotypes, and isolated resistance arteries demonstrated similar sensitivity to α1‐adrenergic receptor‐mediated vasoconstriction. Conclusions These findings specify that acute stress‐induced activation of endothelium‐derived ET‐1 and subsequent endothelin A receptor activation is a novel mediator of the blood pressure response to acute psychosocial stress.
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Affiliation(s)
- Brandon M Fox
- Cardio-Renal Physiology and Medicine Section, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, AL
| | - Bryan K Becker
- Cardio-Renal Physiology and Medicine Section, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, AL
| | - Analia S Loria
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Kelly A Hyndman
- Cardio-Renal Physiology and Medicine Section, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, AL
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine Section, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, AL
| | | | - Robin Johns
- College of Nursing, Augusta University, Augusta, GA
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Japan
| | - David M Pollock
- Cardio-Renal Physiology and Medicine Section, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, AL.,Medical College of Georgia, Augusta University, Augusta, GA
| | - Jennifer S Pollock
- Cardio-Renal Physiology and Medicine Section, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, AL .,Medical College of Georgia, Augusta University, Augusta, GA
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9
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Becker BK, Speed JS, Powell M, Pollock DM. Activation of neuronal endothelin B receptors mediates pressor response through alpha-1 adrenergic receptors. Physiol Rep 2017; 5:5/4/e13077. [PMID: 28219980 PMCID: PMC5328762 DOI: 10.14814/phy2.13077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 11/10/2016] [Accepted: 11/12/2016] [Indexed: 12/20/2022] Open
Abstract
Abnormalities in activity of the endothelin (ET) system have been widely reported in a number of cardiovascular disease states such as hypertension and heart failure. Although the vascular responses to ET are well established, the interaction between ET and other important modulators of blood pressure, such as the sympathetic nervous system, are less understood. Previous reports implicate ET signaling through ET type B (ETB) receptors in increasing neuronal activity. Therefore, we hypothesized that activation of ETB receptors on sympathetic nerves would increase blood pressure through an adrenergic‐mediated mechanism. Thus, we used anesthetized ETB‐deficient rats, which only express functional ETB receptors on adrenergic neurons, and genetic controls, which express functional ETB receptors in vascular tissue and kidney epithelium. We determined the pressor response to the selective ETB receptor agonist sarafotoxin c (S6c). Separate groups of rats were treated with the α1‐adrenergic receptor antagonist prazosin or the β‐adrenergic receptor antagonist propranolol to elucidate the role of adrenergic signaling in mediating the blood pressure response. We observed a dose‐dependent pressor response to S6c in ETB‐deficient rats that was reversed by prazosin treatment and augmented by propranolol. In genetic control rats, the effects of S6c on sympathetic neurons were mostly masked by the direct activity of ETB receptor activation on the vasculature. Heart rate was mostly unaffected by S6c across all groups and treatments. These results suggest that ETB activation on sympathetic neurons causes an increase in blood pressure mediated through α1‐adrenergic receptor signaling.
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Affiliation(s)
- Bryan K Becker
- Division of Nephrology, Department of Medicine, Cardio-Renal Physiology and Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Joshua S Speed
- Division of Nephrology, Department of Medicine, Cardio-Renal Physiology and Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Mackenzie Powell
- Division of Nephrology, Department of Medicine, Cardio-Renal Physiology and Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Division of Nephrology, Department of Medicine, Cardio-Renal Physiology and Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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10
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Jaimes R, Swiercz A, Sherman M, Muselimyan N, Marvar PJ, Posnack NG. Plastics and cardiovascular health: phthalates may disrupt heart rate variability and cardiovascular reactivity. Am J Physiol Heart Circ Physiol 2017; 313:H1044-H1053. [PMID: 28842438 PMCID: PMC5792203 DOI: 10.1152/ajpheart.00364.2017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/17/2017] [Accepted: 08/17/2017] [Indexed: 12/11/2022]
Abstract
Plastics have revolutionized medical device technology, transformed hematological care, and facilitated modern cardiology procedures. Despite these advances, studies have shown that phthalate chemicals migrate out of plastic products and that these chemicals are bioactive. Recent epidemiological and research studies have suggested that phthalate exposure adversely affects cardiovascular function. Our objective was to assess the safety and biocompatibility of phthalate chemicals and resolve the impact on cardiovascular and autonomic physiology. Adult mice were implanted with radiofrequency transmitters to monitor heart rate variability, blood pressure, and autonomic regulation in response to di-2-ethylhexyl-phthalate (DEHP) exposure. DEHP-treated animals displayed a decrease in heart rate variability (-17% SD of normal beat-to-beat intervals and -36% high-frequency power) and an exaggerated mean arterial pressure response to ganglionic blockade (31.5% via chlorisondamine). In response to a conditioned stressor, DEHP-treated animals displayed enhanced cardiovascular reactivity (-56% SD major axis Poincarè plot) and prolonged blood pressure recovery. Alterations in cardiac gene expression of endothelin-1, angiotensin-converting enzyme, and nitric oxide synthase may partly explain these cardiovascular alterations. This is the first study to show an association between phthalate chemicals that are used in medical devices with alterations in autonomic regulation, heart rate variability, and cardiovascular reactivity. Because changes in autonomic balance often precede clinical manifestations of hypertension, atherosclerosis, and conduction abnormalities, future studies are warranted to assess the downstream impact of plastic chemical exposure on end-organ function in sensitive patient populations. This study also highlights the importance of adopting safer biomaterials, chemicals, and/or surface coatings for use in medical devices.NEW & NOTEWORTHY Phthalates are widely used in the manufacturing of consumer and medical products. In the present study, di-2-ethylhexyl-phthalate exposure was associated with alterations in heart rate variability and cardiovascular reactivity. This highlights the importance of investigating the impact of phthalates on health and identifying suitable alternatives for medical device manufacturing.
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Affiliation(s)
- Rafael Jaimes
- 1Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, District of Columbia; ,2Children’s National Heart Institute, Children’s National Health System, Washington, District of Columbia; and
| | - Adam Swiercz
- 3Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Meredith Sherman
- 1Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, District of Columbia;
| | - Narine Muselimyan
- 3Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Paul J. Marvar
- 3Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia; .,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia; and.,Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
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11
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Pan DS, Feng SZ, Cao P, Li JJ. Endothelin B receptor promotes the proliferation and immune escape of malignant gliomas. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2017; 46:1230-1235. [PMID: 28841806 DOI: 10.1080/21691401.2017.1366336] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE As a kind of difficult to cure tumour, malignant gliomas have attracted widespread attention. The proliferation and immune escape of tumour cells were closely related to the development of malignant gliomas. The aim of this study was to investigate the role of endothelin B receptor (NTBR) in gliomas. METHODS RT-PCR was used to detect the expression of NTBR mRNA in glioma tissue and glioma cell lines. The expression of NTBR in glioma tissues was detected by immunohistochemistry. MTT assay was used to detect the viability of U87 cells after adding NTBR. Cell cloning assay was used to detect the cell proliferation ability. Western blot was used to detect the expression of TGF-β and the expression of Treg after adding NTBR to U87. RESULT The expression of NTBR in glioma tissues and cells was significantly higher than that in the control group by RT-PCR. After adding NTBR, cell proliferation of U87 was significantly enhanced and TGF-β and Treg were significantly expressed. It was suggested that NTBR could contribute to tumour immune escape in glioma, and it was found that there was a positive correlation between NTBR expression and different stages in malignant gliomas. CONCLUSION Endothelin B receptor can increase the proliferation of glioma cells and tumour immune escape. The expression of endothelin B is closely related to the clinical stage of glioma.
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Affiliation(s)
- Dong-Sheng Pan
- a Department of Neurosurgery , The General Hospital of Shenyang Military , Shenyang , Liaoning , China
| | - Si-Zhe Feng
- a Department of Neurosurgery , The General Hospital of Shenyang Military , Shenyang , Liaoning , China
| | - Peng Cao
- a Department of Neurosurgery , The General Hospital of Shenyang Military , Shenyang , Liaoning , China
| | - Jin-Jiang Li
- a Department of Neurosurgery , The General Hospital of Shenyang Military , Shenyang , Liaoning , China
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12
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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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