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Shen Y, Kim YJ, Ryu PD. Adrenergic Control of Primo Tissue Size in Rats. J Acupunct Meridian Stud 2022; 15:25-36. [DOI: 10.51507/j.jams.2022.15.1.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/20/2021] [Accepted: 12/06/2021] [Indexed: 11/03/2022] Open
Affiliation(s)
- Yiming Shen
- Department of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute of Veterinary Sciences, Seoul National University, Seoul, Korea
| | - Yu Jeong Kim
- Department of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute of Veterinary Sciences, Seoul National University, Seoul, Korea
| | - Pan Dong Ryu
- Department of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute of Veterinary Sciences, Seoul National University, Seoul, Korea
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Adipocytes initiate an adipose-cerebral-peripheral sympathetic reflex to induce insulin resistance during high-fat feeding. Clin Sci (Lond) 2019; 133:1883-1899. [PMID: 31477624 DOI: 10.1042/cs20190412] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/06/2019] [Accepted: 09/02/2019] [Indexed: 01/22/2023]
Abstract
The underlying mechanism by which amassing of white adipose tissue in obesity regulates sympathetic nerve system (SNS) drive to the tissues responsible for glucose disposal, and causes insulin resistance (IR), remains unknown. We tested the hypothesis that high-fat (HF) feeding increases afferent impulses from white adipose tissue that reflexively elevate efferent nerve activity to skeletal muscle (SM) and adipose tissue to impair their local glucose uptake. We also investigated how salt-intake can enhance IR. HF-fed rats received a normal salt (0.4%) or high salt (4%) diet for 3 weeks. High-salt intake in HF fed rats decreased insulin-stimulated 2-deoxyglucose uptake by over 30% in white adipose tissue and SM, exacerbated inflammation, and impaired their insulin signaling and glucose transporter 4 (Glut4) trafficking. Dietary salt in HF fed rats also increased the activity of the adipose-cerebral-muscle renin-angiotensin system (RAS) axes, SNS, and reactive oxygen species (ROS). Insulin sensitivity was reduced by 32% in HF rats during high-salt intake, but was improved by over 62% by interruption of central RAS and SNS drive, and by over 45% by denervation or deafferentation of epididymal fat (all P<0.05). Our study suggest that a HF diet engages a sympathetic reflex from the white adipose tissue that activates adipose-cerebral-muscle RAS/ROS axes and coordinates a reduction in peripheral glucose uptake. These are all enhanced by salt-loading. These findings provide new insight into the role of a reflex initiated in adipose tissue in the regulation of glucose homeostasis during HF feeding that could lead to new therapeutic approaches to IR.
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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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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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Endothelin receptors, renal effects and blood pressure. Curr Opin Pharmacol 2015; 21:25-34. [DOI: 10.1016/j.coph.2014.12.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 11/23/2022]
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Pollock DM. 2013 Dahl Lecture: American Heart Association council for high blood pressure research clarifying the physiology of endothelin. Hypertension 2014; 63:e110-7. [PMID: 24614220 DOI: 10.1161/hypertensionaha.114.02441] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- David M Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35233.
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D'Angelo G, Loria AS, Pollock DM, Pollock JS. Endothelin activation of reactive oxygen species mediates stress-induced pressor response in Dahl salt-sensitive prehypertensive rats. Hypertension 2010; 56:282-9. [PMID: 20547970 DOI: 10.1161/hypertensionaha.110.152629] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Experiments were designed to test the hypothesis that endothelin (ET) and/or reactive oxygen species contribute to the pressor response induced by acute air jet stress in normotensive Dahl salt-sensitive rats maintained on a normal salt diet (prehypertensive). Mean arterial pressure was chronically monitored by telemetry before and after 3-day treatment with the free radical scavenger 4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl (Tempol) or ET receptor antagonists ABT-627 (ET A antagonist) or A-182086 (ET A/B antagonist) supplied in the drinking water. Rats were restrained and subjected to pulsatile air jet stress (3 minutes). Plasma samples at baseline and during acute stress were analyzed for 8-isoprostane (measure of reactive oxygen species production) and ET. Neither Tempol nor ET receptor antagonist treatment had an effect on baseline mean arterial pressure or plasma 8-isoprostane. The pressor response to acute stress was accompanied by significant increases in plasma 8-isoprostane and ET. Tempol significantly reduced both the total pressor response (area under the curve) and the stress-mediated increase in plasma 8-isoprostane; conversely, Tempol had no effect on the stress-induced increase in plasma ET. Combined ET(A/B) antagonism, but not selective ET(A) receptor blockade, similarly suppressed the pressor response to stress and stress-mediated rise in 8-isoprostane. Together these results indicate that reactive oxygen species contribute to the pressor response to acute air jet stress. Furthermore, the increase in reactive oxygen species occurs downstream of ET(B) receptor activation.
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Affiliation(s)
- Gerard D'Angelo
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA
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Zhao TC, Zhang LX, Cheng G, Liu JT. gp-91 mediates histone deacetylase inhibition-induced cardioprotection. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:872-80. [PMID: 20433879 DOI: 10.1016/j.bbamcr.2010.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Revised: 04/01/2010] [Accepted: 04/19/2010] [Indexed: 01/05/2023]
Abstract
We have recently shown that the inhibition of histone deacetylases (HDAC) protects the heart against ischemia and reperfusion (I/R) injury. The mechanism by which HDAC inhibition induces cardioprotection remains unknown. We sought to investigate whether the genetic disruption of gp-91, a subunit of NADPH-oxidase, would mitigate cardioprotection of HDAC inhibition. Wild-type and gp-91(-)(/-) mice were treated with a potent inhibitor of HDACs, trichostatin A (TSA, 0.1 mg/kg, i.p.). Twenty-four hours later, the perfused hearts were subjected to 30 min of ischemia and 30 min of reperfusion. HDAC inhibition in wild-type mice produced marked improvements in ventricular functional recovery and the reduction of infarct size. TSA-induced cardioprotection was eliminated with genetic deletion of gp91. Notably, Western blot and immunostaining displayed a significant increase in gp-91 in myocardium following HDAC inhibition, which resulted in a mildly subsequent increase in the production of reactive oxygen species (ROS). The pre-treatment of H9c2 cardiomyoblasts with TSA (50 nmol/l) decreased cell necrosis and increased viability in response to simulated ischemia (SI), which was abrogated by the transfection of cells with gp-91 siRNA, but not by scrambled siRNA. Furthermore, treatment of PLB-985 gp91(+/+) cells with TSA increased the resistance to SI, which also diminished with genetic disruption of gp91 in gp91(phox)-deficient PLB-985 cells. TSA treatment inhibited the increased active caspase-3 in H9c2 cardiomyoblasts and PLB-985 gp91(+/+) cells exposed to SI, which were prevented by knockdown of gp-91 by siRNA. These results suggest that a cascade consisting of gp-91 and HDAC inhibition plays an essential role in orchestrating the cardioprotective effect.
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Affiliation(s)
- Ting C Zhao
- Department of Surgery, Roger William Medical Center, Boston University Medical School, Providence, RI 02908, USA.
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