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Lilley RJ, Taylor KD, Wildman SSP, Peppiatt-Wildman CM. Inflammatory mediators act at renal pericytes to elicit contraction of vasa recta and reduce pericyte density along the kidney medullary vascular network. Front Physiol 2023; 14:1194803. [PMID: 37362447 PMCID: PMC10288992 DOI: 10.3389/fphys.2023.1194803] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/01/2023] [Indexed: 06/28/2023] Open
Abstract
Introduction: Regardless of initiating cause, renal injury promotes a potent pro-inflammatory environment in the outer medulla and a concomitant sustained decrease in medullary blood flow (MBF). This decline in MBF is believed to be one of the critical events in the pathogenesis of acute kidney injury (AKI), yet the precise cellular mechanism underlying this are still to be fully elucidated. MBF is regulated by contractile pericyte cells that reside on the descending vasa recta (DVR) capillaries, which are the primary source of blood flow to the medulla. Methods: Using the rat and murine live kidney slice models, we investigated the acute effects of key medullary inflammatory mediators TNF-α, IL-1β, IL-33, IL-18, C3a and C5a on vasa recta pericytes, the effect of AT1-R blocker Losartan on pro-inflammatory mediator activity at vasa recta pericytes, and the effect of 4-hour sustained exposure on immunolabelled NG2+ pericytes. Results and discussion: Exposure of rat and mouse kidney slices to TNF-α, IL-18, IL-33, and C5a demonstrated a real-time pericyte-mediated constriction of DVR. When pro-inflammatory mediators were applied in the presence of Losartan the inflammatory mediator-mediated constriction that had previously been observed was significantly attenuated. When live kidney slices were exposed to inflammatory mediators for 4-h, we noted a significant reduction in the number of NG2+ positive pericytes along vasa recta capillaries in both rat and murine kidney slices. Data collected in this study demonstrate that inflammatory mediators can dysregulate pericytes to constrict DVR diameter and reduce the density of pericytes along vasa recta vessels, further diminishing the regulatory capacity of the capillary network. We postulate that preliminary findings here suggest pericytes play a role in AKI.
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Affiliation(s)
- Rebecca J. Lilley
- Division of Natural Sciences, University of Kent, Kent, United Kingdom
| | - Kirsti D. Taylor
- Division of Natural Sciences, University of Kent, Kent, United Kingdom
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Galán M, Jiménez-Altayó F. Small Resistance Artery Disease and ACE2 in Hypertension: A New Paradigm in the Context of COVID-19. Front Cardiovasc Med 2020; 7:588692. [PMID: 33195477 PMCID: PMC7661633 DOI: 10.3389/fcvm.2020.588692] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 10/02/2020] [Indexed: 01/08/2023] Open
Abstract
Cardiovascular disease causes almost one third of deaths worldwide, and more than half are related to primary arterial hypertension (PAH). The occurrence of several deleterious events, such as hyperactivation of the renin–angiotensin system (RAS), and oxidative and inflammatory stress, contributes to the development of small vessel disease in PAH. Small resistance arteries are found at various points through the arterial tree, act as the major site of vascular resistance, and actively regulate local tissue perfusion. Experimental and clinical studies demonstrate that alterations in small resistance artery properties are important features of PAH pathophysiology. Diseased small vessels in PAH show decreased lumens, thicker walls, endothelial dysfunction, and oxidative stress and inflammation. These events may lead to altered blood flow supply to tissues and organs, and can increase the risk of thrombosis. Notably, PAH is prevalent among patients diagnosed with COVID-19, in whom evidence of small vessel disease leading to cardiovascular pathology is reported. The SARS-Cov2 virus, responsible for COVID-19, achieves cell entry through an S (spike) high-affinity protein binding to the catalytic domain of the angiotensin-converting enzyme 2 (ACE2), a negative regulator of the RAS pathway. Therefore, it is crucial to examine the relationship between small resistance artery disease, ACE2, and PAH, to understand COVID-19 morbidity and mortality. The scope of the present review is to briefly summarize available knowledge on the role of small resistance artery disease and ACE2 in PAH, and critically discuss their clinical relevance in the context of cardiovascular pathology associated to COVID-19.
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Affiliation(s)
- María Galán
- Institut de Recerca del Hospital de la Santa Creu i Sant Pau, IIB Sant Pau, Barcelona, Spain.,Centro de Investigación en Red de Enfermedades Cardiovasculares, Madrid, Spain
| | - Francesc Jiménez-Altayó
- Departament de Farmacologia, de Terapèutica i de Toxicologia, Facultat de Medicina, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
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Aliskiren attenuates the effects of interleukin-6 on endothelial nitric oxide synthase and caveolin-1 in human aortic endothelial cells. Nitric Oxide 2016; 61:45-54. [DOI: 10.1016/j.niox.2016.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 10/15/2016] [Accepted: 10/18/2016] [Indexed: 11/21/2022]
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Rinne P, Ahola-Olli A, Nuutinen S, Koskinen E, Kaipio K, Eerola K, Juonala M, Kähönen M, Lehtimäki T, Raitakari OT, Savontaus E. Deficiency in Melanocortin 1 Receptor Signaling Predisposes to Vascular Endothelial Dysfunction and Increased Arterial Stiffness in Mice and Humans. Arterioscler Thromb Vasc Biol 2015; 35:1678-86. [DOI: 10.1161/atvbaha.114.305064] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 04/16/2015] [Indexed: 12/11/2022]
Abstract
Objective—
The melanocortin 1 receptor (MC1-R) is expressed by vascular endothelial cells and shown to enhance nitric oxide (NO) availability and vasodilator function on pharmacological stimulation. However, the physiological role of MC1-R in the endothelium and its contribution to vascular homeostasis remain unresolved. We investigated whether a lack of functional MC1-R signaling carries a phenotype with predisposition to vascular abnormalities.
Approach and Results—
Recessive yellow mice (MC1R
e/e
), deficient in MC1-R signaling, and their wild-type littermates were studied for morphology and functional characteristics of the aorta. MC1R
e/e
mice showed increased collagen deposition and arterial stiffness accompanied by an elevation in pulse pressure. Contractile capacity and NO-dependent vasodilatation were impaired in the aorta of MC1R
e/e
mice supported by findings of decreased NO availability. These mice also displayed elevated levels of systemic and local cytokines. Exposing the mice to high-sodium diet or acute endotoxemia revealed increased susceptibility to inflammation-driven vascular dysfunction. Finally, we investigated whether a similar phenotype can be found in healthy human subjects carrying variant
MC1-R
alleles known to attenuate receptor function. In a longitudinal analysis of 2001 subjects with genotype and ultrasound data (The Cardiovascular Risk in Young Finns Study), weak MC1-R function was associated with lower flow-mediated dilatation response of the brachial artery and increased carotid artery stiffness.
Conclusions—
The present study demonstrates that deficiency in MC1-R signaling is associated with increased arterial stiffness and impairment in endothelium-dependent vasodilatation, suggesting a physiological role for MC1-R in the regulation of arterial tone.
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Affiliation(s)
- Petteri Rinne
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Ari Ahola-Olli
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Salla Nuutinen
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Emilia Koskinen
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Katja Kaipio
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Kim Eerola
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Markus Juonala
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Mika Kähönen
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Terho Lehtimäki
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Olli T. Raitakari
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
| | - Eriika Savontaus
- From the Department of Pharmacology, Drug Development and Pharmaceutics (P.R., S.N., E.K., K.E.,E.S.), the Research Centre of Applied and Preventive Cardiovascular Medicine (A.A-O., O.T.R.), and Department of Pathology (K.K), University of Turku, Turku, Finland; Division of Medicine (M.J.), Department of Clinical Physiology and Nuclear Medicine (O.T.R), and the Unit of Clinical Pharmacology (E.S.), Turku University Hospital, Turku, Finland; Department of Clinical Physiology, University of Tampere
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Zhang B, Niu W, Xu D, Li Y, Liu M, Wang Y, Luo Y, Zhao P, Liu Y, Dong M, Sun R, Dong H, Li Z. Oxymatrine prevents hypoxia- and monocrotaline-induced pulmonary hypertension in rats. Free Radic Biol Med 2014; 69:198-207. [PMID: 24440469 DOI: 10.1016/j.freeradbiomed.2014.01.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 01/07/2014] [Accepted: 01/08/2014] [Indexed: 02/02/2023]
Abstract
Pulmonary hypertension is a progressive disease characterized by marked pulmonary arterial remodeling and increased vascular resistance. Inflammation and oxidative stress promote the development of pulmonary hypertension. Oxymatrine, one of the main active components of the Chinese herb Sophora flavescens Ait. (Kushen), plays anti-inflammatory and antioxidant protective roles, which effects on pulmonary arteries remain unclear. This study aimed to investigate the effects of oxymatrine on pulmonary hypertension development. Sprague-Dawley rats were exposed to hypoxia for 28 days or injected with monocrotaline, to develop pulmonary hypertension, along with administration of oxymatrine (50mg/kg/day). Hemodynamics and pulmonary arterial remodeling data from the rats were then obtained. The antiproliferative effect of oxymatrine was verified by in vitro assays. The inflammatory cytokine mRNA levels and leukocyte and T cell accumulation in lung tissue were detected. The antioxidative effects of oxymatrine were explored in vitro. Our study shows that oxymatrine treatment attenuated right-ventricular systolic pressure and pulmonary arterial remodeling induced by hypoxia or monocrotaline and inhibited proliferation of pulmonary arterial smooth muscle cells (PASMCs). Increased expression of inflammatory cytokine mRNA and accumulation of leukocytes and T cells around the pulmonary arteries were suppressed with oxymatrine administration. Under hypoxic conditions, oxymatrine significantly upregulated Nrf2 and antioxidant protein SOD1 and HO-1 expression, but downregulated hydroperoxide levels in PASMCs. In summary, this study indicates that oxymatrine may prevent pulmonary hypertension through its antiproliferative, anti-inflammatory, and antioxidant effects, thus providing a promising pharmacological avenue for treating pulmonary hypertension.
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Affiliation(s)
- Bo Zhang
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China.
| | - Wen Niu
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Dunquan Xu
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Yanyan Li
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Manling Liu
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Yanxia Wang
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Ying Luo
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Pengtao Zhao
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Yi Liu
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Mingqing Dong
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China
| | - Rihe Sun
- Xi'an YiLe Bio-Tech Laboratory, Xi'an 710075, People's Republic of China
| | - Haiying Dong
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China.
| | - Zhichao Li
- Department of Pathology, Xijing Hospital and Department of Pathology and Pathophysiology, Fourth Military Medical University, Xi'an 710032, People's Republic of China.
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6
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Carnovale C, Perrone V, Borsadoli C, Mambrini A, Speziali A, Froldi G, Antoniazzi S, Magistro L, Clementi E, Radice S. A case of urinary incontinence by hydroxychloroquine in a geriatric patient. J Clin Pharm Ther 2012. [DOI: 10.1111/jcpt.12024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- C. Carnovale
- Scientific Institute; IRCCS Eugenio Medea; Lecco Italy
| | - V. Perrone
- Unit of Clinical Pharmacology; Department of Biomedical and Clinical Sciences; University Hospital ‘Luigi Sacco’; Università di Milano; Milan Italy
| | - C. Borsadoli
- Pharmaceutical Service; Azienda Sanitaria Locale di Mantova; Mantua Italy
| | - A. Mambrini
- Physician, Azienda Sanitaria Locale di Mantova; Mantua Italy
| | - A. Speziali
- Pharmaceutical Service; Azienda Sanitaria Locale di Mantova; Mantua Italy
| | - G. Froldi
- Pharmaceutical Service; Azienda Sanitaria Locale di Mantova; Mantua Italy
| | - S. Antoniazzi
- Unit of Clinical Pharmacology; Department of Biomedical and Clinical Sciences; University Hospital ‘Luigi Sacco’; Università di Milano; Milan Italy
| | - L. Magistro
- Postgraduate School of Clinical Pharmacology; Department of Pharmacology “E. Trabucchi”; Università di Milano, Milan Italy
| | - E. Clementi
- Scientific Institute; IRCCS Eugenio Medea; Lecco Italy
- Unit of Clinical Pharmacology; Department of Biomedical and Clinical Sciences; University Hospital ‘Luigi Sacco’; Università di Milano; Milan Italy
| | - S. Radice
- Unit of Clinical Pharmacology; Department of Biomedical and Clinical Sciences; University Hospital ‘Luigi Sacco’; Università di Milano; Milan Italy
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Macrophage migration inhibitory factor contributes to hypoxic pulmonary vasoconstriction in rats. Microvasc Res 2011; 83:205-12. [PMID: 22005047 DOI: 10.1016/j.mvr.2011.09.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Revised: 09/09/2011] [Accepted: 09/30/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hypoxic pulmonary vasoconstriction may lead to pulmonary hypertension, but the underlying mechanisms of persistent vasoconstriction are still unclear. There is evidence that pulmonary inflammation contributes to the abnormalities of function in the pulmonary artery (PA) following chronic hypoxia exposure. Macrophage migration inhibitory factor (MIF) is an important pro-inflammatory cytokine, and we found that expression of MIF was increased in the smooth muscle of PA from hypoxic pulmonary hypertensive rats. Therefore, the aim of the study was to investigate the role of MIF in modulating vasoreactivity of isolated PA rings. METHODS Sprague-Dawley rats were challenged by intermittent chronic hypoxia exposure for 4 weeks to establish hypoxic pulmonary hypertension models. Subsequently, immunohistochemistry and western blot assay were used to examine the MIF expression in pulmonary artery. Moreover, isometric force displacement was measured in isolated intrapulmonary artery. RESULTS In the isolated PA, our results showed that MIF mediated the enhanced pulmonary arterial vasoconstriction in response to chronic hypoxia, and the delayed hypoxic constriction in a biphasic pattern of constriction occurs in response to acute hypoxia. We also present the finding that MIF had no effect on force on its own, but concentration-dependently potentiated constrictions pre-evoked by phenylephrine under normoxic condition. The potentiation was independent of the endothelium. MIF-induced potentiation of phenylephrine-evoked constriction was partially inhibited by PKC inhibitor chelerythrine, p38 inhibitor SB 203580, ERK1/2 inhibitor U0126, respectively. CONCLUSIONS Our results suggested that MIF enhanced vasoconstriction of pulmonary artery elicited by agonist through PKC, p38 and ERK1/2 signal pathways, which may contributes to hypoxic pulmonary vasoconstriction.
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Interleukin-6 inhibits endothelial nitric oxide synthase activation and increases endothelial nitric oxide synthase binding to stabilized caveolin-1 in human vascular endothelial cells. J Hypertens 2010; 28:940-51. [PMID: 20375905 DOI: 10.1097/hjh.0b013e32833992ef] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE We hypothesized a possible mechanism for atherosclerosis in which interleukin-6 (IL-6) might affect the endothelial nitric oxide synthase (eNOS)-caveolin-1 interaction and result in decreased nitric oxide bioavailability in the setting of low-grade inflammation. METHODS Because eNOS and caveolin-1 are crucial for vascular tone control, we studied the effects of IL-6 on the expression and activation of eNOS and caveolin-1 in human vascular endothelial cells. RESULTS IL-6 inhibited the phosphorylation of eNOS at Ser1177 and the bradykinin-stimulated nitric oxide production; however, eNOS protein expression was not changed. In addition, IL-6 inhibited bradykinin-stimulated Akt phosphorylation at Ser473 and Thr 308 without affecting the Akt protein expression. IL-6 did not alter the mRNA level of caveolin-1; however, the caveolin-1 protein level was significantly increased dose-dependently. The binding of eNOS and caveolin-1 in endothelial cells, as demonstrated by coimmunoprecipitation assay, was increased by IL-6 treatment. IL-6 treatment was found to stabilize caveolin-1 protein and its half-life was estimated to prolong from 7.5 h to longer than 12 h. Furthermore, treatment with PD98059 and short interference RNA of extracellular signal-regulated kinase gene reversed the effects of IL-6 on eNOS and caveolin-1. CONCLUSION In addition to decreasing Akt phosphorylation, the results of this study demonstrate, for the first time, the molecular mechanism underlying the effect of IL-6 to decrease the nitric oxide bioavailability by increasing the half-life and, therefore, the protein levels of caveolin-1. The increased caveolin-1 proteins bind more eNOS and consequently decrease eNOS activation by reducing the Ser1177 phosphorylation.
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Gao Y, Yang Y, Guan Q, Pang X, Zhang H, Zeng D. IL-1beta modulate the Ca(2+)-activated big-conductance K channels (BK) via reactive oxygen species in cultured rat aorta smooth muscle cells. Mol Cell Biochem 2009; 338:59-68. [PMID: 19949838 DOI: 10.1007/s11010-009-0338-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 11/19/2009] [Indexed: 10/20/2022]
Abstract
The large conductance Ca(2+)-activated K(+) (BK) channel, abundantly expressed in vascular smooth muscle cells, plays a critical role in controlling vascular tone. Activation of BK channels leads to membrane hyperpolarization and promotes vasorelaxation. BK channels are activated either by elevation of the intracellular Ca(2+) concentration or by membrane depolarization. It is also regulated by a diversity of vasodilators and vasoconstrictors. Interleukin-1beta (IL-1beta) is one of the cytokines that play important roles in the development and progression of a variety of cardiovascular diseases. The effects of IL-1beta on vascular reactivity are controversial, and little is known about the modulation of BK channel function by IL-1beta. In this study, we investigated how IL-1beta modulates BK channel function in cultured arterial smooth muscle cells (ASMCs), and examined the role of H(2)O(2) in the process. We demonstrated that IL-1beta had biphasic effects on BK channel function and membrane potential of ASMCs, that is both concentration and time dependent. IL-1beta increased BK channel-dependent K(+) current and hyperpolarized ASMCs when applied for 30 min. While long-term (24-48 h) treatment of IL-1beta resulted in decreased expression of alpha-subunit of BK channel, suppressed BK channel activity, decreased BK channel-dependent K(+) current and depolarization of the cells. H(2)O(2) scavenger catalase completely abolished the early effect of IL-1beta, while it only partly diminished the long-term effect of IL-1beta. These results may provide important molecular mechanisms for therapeutic strategies targeting BK channel in inflammation-related diseases.
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Affiliation(s)
- Yuan Gao
- Department of Cardiology, the First Affiliated Hospital, China Medical University, Heping District, Shengyang, People's Republic of China
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10
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Han JH, Lee MY, Myung SC. The effect of endothelin-1 on the production of interleukin-6 in cultured human detrusor smooth muscle cells, and the effect of interleukin-6 on the contractile response of bladder smooth muscle strips from rats. BJU Int 2009; 104:707-12. [PMID: 19389001 DOI: 10.1111/j.1464-410x.2009.08465.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To determine the effect of endothelin-1 (ET-1) on the production of interleukin-6 (IL-6) in cultured human detrusor smooth muscle cells (HDSMCs) and the effect of IL-6 on the contractile response of bladder smooth muscle strips from rats. MATERIALS AND METHODS The expression of IL-6 mRNA and production of IL-6 protein in cultured HDSMCs treated with the different concentrations of ET-1 were assayed by reverse transcriptase-polymerase chain reaction and specific enzyme-linked immunosorbent assay, respectively. The strips from Sprague-Dawley rats were either untreated or treated with 1 ng/mL of IL-6 for 60 min. Using increasing cumulative concentrations of acetylcholine (ACh), bethanechol (BCh), or sodium nitroprusside, we assessed the concentration-contraction or the relaxation responses. In cystitis-induced strips, change of contractions induced by noradrenaline (NA) with or without treatment of IL-6 were assessed. The IL-6-treated strips were incubated for 30 min in the presence or absence indomethacin or SQ29548, and then the effects on ACh- or BCh-induced contractions were measured. RESULTS The expression of IL-6 mRNA and the production of IL-6 protein on the cultured HDSMCs pretreated by ET-1 were significantly higher than in the control (P<0.05). The ACh- and BCh-induced contractions were increased in the IL-6 pretreated strips from both dome and trigone, regardless of the presence of urothelium (P<0.05). The presence of cystitis augmented the NA-induced contractions (P<0.05). The contractions induced by ACh and BCh were inhibited by indomethacin and SQ29548. CONCLUSIONS ET-1 induces expression of IL-6 mRNA and production of IL-6 protein on HDSMCs. IL-6 enhances detrusor smooth muscle contractility via the muscarinic or adrenergic receptor pathway.
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Affiliation(s)
- June Hyun Han
- Department of Urology, KEPCO Medical Foundation Hanil General Hospital, and Department of Physiology, College of Medicine, Chung-Ang University, Seoul, Korea
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11
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Myung SC, Han JH, Song KK, Kang GH, Lee SY, Kim TH, Lee MY, Kim HW, Kim SC. The effects of interleukin-6 on the contraction and relaxation responses of the cavernous smooth muscle from rats. Eur J Pharmacol 2008; 589:228-32. [PMID: 18555215 DOI: 10.1016/j.ejphar.2008.04.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Revised: 03/05/2008] [Accepted: 04/24/2008] [Indexed: 11/19/2022]
Abstract
The purpose of this study is to elucidate the effect of IL-6 on the vasomotor reactivity of the corpus cavernosum of the rats. The strips were either left untreated or treated with 1 ng/ml of IL-6 for 60 min. By increasing concentrations of phenylephrine, acetylcholine, or sodium nitroprusside, we assessed concentration-contraction or relaxation responses. The IL-6-treated strips were incubated for 30 min with or without L-NAME (N(W)-nitro-L-arginine methyl ester), L-arginine, indomethacin, BQ-123 (an endothelin receptor A inhibitor), or SQ 29,548 (a thromboxane A(2) [TXA(2)] receptor blocker), and the effects on phenylephrine-induced contraction or acetylcholine-induced relaxation of phenylephrine-induced contraction were measured. The contractile responses to phenylephrine were significantly enhanced in the IL-6-treated strips, compared with the IL-6-nontreated strips, and the relaxation responses to acetylcholine were significantly inhibited in the IL-6-treated group compared with the IL-6-nontreated group. But after endothelial denudation, there was no difference between the IL-6-treated strips and the IL-6-nontreated strips on the contraction-relaxation responses to phenylephrine or acetylcholine. The relaxation responses to sodium nitroprusside were not inhibited in both groups. L-NAME completely inhibited the relaxation response to acetylcholine in the IL-6-treated strips, as well as the IL-6-nontreated strips. Indomethacin and SQ 29,548 significantly inhibited the increased contractile responses to phenylephrine in the IL-6-treated strips. But BQ 123 rarely affected the same responses. L-arginine reversed the inhibited relaxation responses to acetylcholine in the IL-6-treated strips. Therefore, IL-6 inhibits endothelium-dependent, NO-mediated relaxation and also enhances alpha(1)-adrenergic receptor-mediated contraction via an endothelium-dependent TXA(2)-mediated mechanism in the corpus cavernosum of the rat.
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MESH Headings
- Animals
- Cyclooxygenase Inhibitors/pharmacology
- Dose-Response Relationship, Drug
- Endothelins/metabolism
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/metabolism
- Enzyme Inhibitors/pharmacology
- Interleukin-6/metabolism
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Synthase/antagonists & inhibitors
- Nitric Oxide Synthase/metabolism
- Penis/blood supply
- Prostaglandin-Endoperoxide Synthases/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, alpha-1/metabolism
- Thromboxane A2/metabolism
- Vasoconstriction/drug effects
- Vasoconstrictor Agents/pharmacology
- Vasodilation/drug effects
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Soon Chul Myung
- Department of Urology, Chung-Ang University Hospital, Seoul, Republic of Korea
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12
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Dorrance AM. Interleukin 1-beta (IL-1beta) enhances contractile responses in endothelium-denuded aorta from hypertensive, but not normotensive, rats. Vascul Pharmacol 2007; 47:160-5. [PMID: 17602892 PMCID: PMC2000828 DOI: 10.1016/j.vph.2007.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 05/14/2007] [Accepted: 05/31/2007] [Indexed: 11/20/2022]
Abstract
BACKGROUND The chronic effects of interleukin 1-beta (IL-beta) on vascular reactivity include augmentation of contraction and relaxation. Few studies have assessed the acute effects of IL-1beta in vessels from hypertensive and normotensive rats. We hypothesized that IL-1beta would enhance constriction in aorta from stroke prone spontaneously hypertensive rats (SHRSP). METHODS Endothelium denuded aortic rings from 12 week-old SHRSP and Wistar Kyoto (WKY) rats were mounted in a myograph and incubated with IL-1beta (20 ng/ml) for 1 h before construction of a phenylephrine dose response curve. Indomethacin (1 microM) and PP-2 (1 microM) were utilized to inhibit cyclooxygenase (COX) and Src-kinase respectively. RESULTS In aorta from SHRSP, IL-1beta caused a significant increase in the force generated over the hour incubation; inhibition of COX or Src-kinase prevented this. The maximum phenylephrine-induced contraction was greater in aorta from SHRSP incubated with IL-1beta than control. COX or Src-kinase inhibition prevented this. IL-1beta had no effect on the vessels from WKY rats. CONCLUSIONS These novel data suggest that IL-1beta has rapid effects on vascular smooth muscle from hypertensive rats to produce constriction and to enhance phenylephrine-induced constriction. The COX and Src-kinase pathways appear to be involved in this response.
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Affiliation(s)
- Anne M Dorrance
- Department of Physiology, Medical College of Georgia, Augusta, GA 30912-3000, USA.
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13
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Abstract
Studies were carried out to determine the effects of IL-1beta on newborn intestinal hemodynamics. IL-1beta increased the release of ET-1 by primary endothelial cells in a dose-dependent manner; as well, it reduced expression of the endothelin (ET) type B (ET(B)) receptor on endothelial cells and increased expression of the ET type A (ET(A)) receptor on vascular smooth muscle cells. IL-1beta increased endothelial cell endothelial nitric oxide (NO) synthase (eNOS) expression but did not enhance eNOS activity as evidenced by release of NO(x) into conditioned medium in response to acetylcholine or shear stress. The effects of IL-1beta on flow-induced dilation were evaluated in terminal mesenteric arteries in vitro. Pretreatment with IL-1beta (1 ng; 4 h) significantly attenuated vasodilation in response to flow rates of 100 and 200 microl/min. This effect was mediated, in part, by the endothelin ET(A) receptor; thus selective blockade of ET(A) receptors with BQ610 nearly restored flow-induced dilation. In contrast, exogenous ET-1 only shifted the diameter-flow curve downward without altering the percent vasodilation in response to flow. The effects of IL-1beta on ileal oxygenation were then studied using in vivo gut loops. Intramesenteric artery infusion of IL-1beta upstream of the gut loop caused ileal vasoconstriction and reduced the arterial-venous O(2) difference across the gut loop; consequently, it reduced ileal oxygenation by 60%. This effect was significantly attenuated by pretreatment with BQ610. These data support a linkage between the proinflammatory cytokine IL-1beta and vascular dysfunction within the intestinal circulation, mediated, at least in part, by the ET system.
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Affiliation(s)
- Philip T Nowicki
- Columbus Children's Research Institute, Children's Hospital, 700 Children's Dr., Columbus, OH 43205, USA.
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14
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Lee DL, Sturgis LC, Labazi H, Osborne JB, Fleming C, Pollock JS, Manhiani M, Imig JD, Brands MW. Angiotensin II hypertension is attenuated in interleukin-6 knockout mice. Am J Physiol Heart Circ Physiol 2005; 290:H935-40. [PMID: 16284237 DOI: 10.1152/ajpheart.00708.2005] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Plasma levels of IL-6 correlate with high blood pressure under many circumstances, and ANG II has been shown to stimulate IL-6 production from various cell types. This study tested the role of IL-6 in mediating the hypertension caused by high-dose ANG II and a high-salt diet. Male C57BL6 and IL-6 knockout (IL-6 KO) mice were implanted with biotelemetry devices and placed in metabolic cages to measure mean arterial pressure (MAP), heart rate (HR), sodium balance, and urinary albumin excretion. Baseline MAP during the control period averaged 114 +/- 1 and 109 +/- 1 mmHg for wild-type (WT) and IL-6 KO mice, respectively, and did not change significantly when the mice were placed on a high-salt diet (HS; 4% NaCl). ANG II (90 ng/min sc) caused a rapid increase in MAP in both groups, to 141 +/- 9 and 141 +/- 4 in WT and KO mice, respectively, on day 2. MAP plateaued at this level in KO mice (134 +/- 2 mmHg on day 14 of ANG II) but began to increase further in WT mice by day 4, reaching an average of 160 +/- 4 mmHg from days 10 to 14 of ANG II. Urinary albumin excretion on day 4 of ANG II was not different between groups (9.18 +/- 4.34 and 8.53 +/- 2.85 microg/2 days for WT and KO mice). By day 14, albumin excretion was nearly fourfold greater in WT mice, but MAP dropped rapidly back to control levels in both groups when the ANG II was stopped after 14 days. Thus the approximately 30 mmHg greater ANG II hypertension in the WT mice suggests that IL-6 contributes significantly to ANG II-salt hypertension. In addition, the early separation in MAP, the albumin excretion data, and the rapid, post-ANG II recovery of MAP suggest an IL-6-dependent mechanism that is independent of renal injury.
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Affiliation(s)
- Dexter L Lee
- Department of Physiology, Medical College of Georgia, Augusta, Georgia 30912-3000, USA.
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15
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Jiménez-Altayó F, Briones AM, Giraldo J, Planas AM, Salaices M, Vila E. Increased Superoxide Anion Production by Interleukin-1β Impairs Nitric Oxide-Mediated Relaxation in Resistance Arteries. J Pharmacol Exp Ther 2005; 316:42-52. [PMID: 16183707 DOI: 10.1124/jpet.105.088435] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The present study was designed to analyze the effect of long-term incubation with interleukin-1beta (IL-1beta) on endothelium-dependent relaxation in rat mesenteric resistance arteries. Vessels were incubated in culture medium with or without IL-1beta (10 ng/ml, 14 h). Changes in lumen diameter were recorded in a pressure myograph. Protein expression, nitrite, and superoxide anion (O(2)(.)) production were evaluated by either Western blot or immunofluorescence, Griess reaction, and ethidium fluorescence, respectively. IL-1beta impaired acetylcholine (ACh) and sodium nitroprusside (SNP) vasodilation and increased nitrite and O(2)(.) production and inducible nitric-oxide synthase (iNOS), xanthine oxidase, and p22(phox) expression. However, neither endothelial nitric-oxide synthase (NOS) nor soluble guanylate cyclase protein expression were affected by IL-1beta treatment. Polyethylene glycol superoxide dismutase partially reversed the impairment of ACh relaxation and abolished the O(2)(.) production observed in IL-1beta-treated arteries. The impairment of ACh relaxation induced by IL-1beta was also partially reversed by the xanthine oxidase inhibitor allopurinol (1 mM) but not by either the NADPH oxidase inhibitor apocynin (0.3 mM) or the inducible NOS inhibitor N-3-aminomethylbenzylacetamidine (1 microM). However, all these inhibitors improved the impaired SNP response. The results of the present study demonstrate that long-term incubation with IL-1beta induces an impairment of the nitric oxide-mediated relaxation in mesenteric resistance arteries through the production of O(2)(.), mainly from xanthine oxidase.
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Affiliation(s)
- Francesc Jiménez-Altayó
- Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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16
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Piepoli AL, De Salvatore G, De Salvia MA, Mitolo CI, Siro-Brigiani G, Marzullo A, Grattagliano I, Mitolo-Chieppa D, Palasciano G, Portincasa P. Indomethacin-induced ileitis is associated with tensiometric, vascular and oxidative changes in the experimental rat model. Eur J Clin Invest 2005; 35:271-8. [PMID: 15816997 DOI: 10.1111/j.1365-2362.2005.01489.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Indomethacin-induced enteritis is a model of inflammatory bowel disease. MATERIALS AND METHODS To further characterize this model, rats received two injections of indomethacin (7.5 mg kg(-1)) 24 h apart and histological damage of intestinal mucosa, oxidative stress, alterations of intestinal motility and mesenteric vascular bed (MVB) reactivity were investigated after 5 days. RESULTS The results show that indomethacin caused several histological and functional changes at the ileal level. In particular, response to carbachol as well as the nonadrenergic-noncholinergic inhibitory response to electrical field stimulation (EFS) was lower in the treated than control rats. Moreover, nitric oxide (NO)-component of the inhibitory response was higher in the treated than control rats. Mesenteric vessels preparations from the treated rats showed increased noradrenaline (NA)-induced perfusion pressure, whereas relaxant responses to acetylcholine, although not significantly reduced in the treated rats, had a higher nitrergic component. This finding suggests that vascular dysfunction may contribute to chronic inflammation. Indomethacin injection also determined acute and severe oxidative stress in ileum mucosa. CONCLUSIONS In conclusion, our study contributes to further characterize the rat model of indomethacin-induced enteritis and suggests that it is suitable for drug screening in rats, as this model can be obtained in a very short period and is simple and reproducible.
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17
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Abstract
Cytokine levels are elevated in many cardiovascular diseases and seem to be implicated in the associated disturbances in vascular reactivity reported in these diseases. Arterial blood pressure is maintained within a normal range by changes in peripheral resistance and cardiac output. Peripheral resistance is mainly determined by small resistance arteries and arterioles. This review focuses on the effects of cytokines, mainly TNF-α, IL-1β, and IL-6, on the reactivity of resistance arteries. The vascular effects of cytokines depend on the balance between the vasoactive mediators released under their influence in the different vascular beds. Cytokines may induce a vasodilatation and hyporesponsiveness to vasoconstrictors that may be relevant to the pathogenesis of septic shock. Cytokines may also induce vasoconstriction or increase the response to vasoconstrictor agents and impair endothelium-dependent vasodilatation. These effects may help predispose to vessel spasm, thrombosis, and atherogenesis and reinforce the link between inflammation and vascular disease.
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18
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Salinthone S, Singer CA, Gerthoffer WT. Inflammatory gene expression by human colonic smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 2004; 287:G627-37. [PMID: 15117678 DOI: 10.1152/ajpgi.00462.2003] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Intestinal mucosal cells and invading leukocytes produce inappropriate levels of cytokines and chemokines in human colitis. However, smooth muscle cells of the airway and vasculature also synthesize cytokines and chemokines. To determine whether human colonic myocytes can synthesize proinflammatory mediators, strips of circular smooth muscle and smooth muscle cells were isolated from human colon. Myocytes and muscle strips were stimulated with 10 ng/ml of IL-1beta, TNF-alpha, and IFN-gamma, respectively. Expression of mRNA for IL-1beta, IL-6, IL-8, and cyclooxygenase-2 (COX-2) was induced within 2 h and continued to increase for 8-12 h. Regulated on activation, normal T cell-expressed and -secreted (RANTES) mRNA expression was slower, appearing at 8 h and increasing linearly through 20 h. Expression of all five mRNAs was inhibited by 0.1 microM MG-132, a proteosome inhibitor that blocks NF-kappaB activation. Expression of IL-1beta, IL-6, IL-8, and COX-2 mRNA was reduced by 30 microM PP1, an Src family tyrosine kinase inhibitor, and by 25 microM SB-203580, a p38 MAPK inhibitor. MAPK/extracellular regulated kinase-1 inhibitor PD-98059 (25 microM) was much less effective. In conclusion, human colonic smooth muscle cells can synthesize and secrete interleukins (IL-1beta and IL-6) and chemokines (IL-8 and RANTES) and upregulate expression of COX-2. Regulation of cytokine, chemokine, and COX-2 mRNA depends on multiple signaling pathways, including Src-family kinases, extracellular regulated kinase, p38 MAPKs, and NF-kappaB. SB-203580 was a consistent, efficacious inhibitor of inflammatory gene expression, suggesting an important role of p38 MAPK in synthetic functions of human colonic smooth muscle.
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Affiliation(s)
- Sonemany Salinthone
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada 89557-0270, USA
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19
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De Salvatore G, Desaphy JF, Piepoli AL, Natale L, De Salvia MA, Mitolo CI, Renna G, Conte-Camerino D, Mitolo-Chieppa D. Functional alterations of mesenteric vascular bed, vas deferens and intestinal tracts in a rat hindlimb unloading model of microgravity. ACTA ACUST UNITED AC 2004; 24:45-54. [PMID: 15458543 DOI: 10.1111/j.1474-8673.2004.00315.x] [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: 12/21/2022]
Abstract
1. Prolonged bed rest or exposure to microgravity may cause several alterations in autonomic nervous system response (ANSR). 2. Hindlimb unloading (HU) rats were used as an animal model of simulated microgravity to investigate ANSR changes. The experiments were carried out to investigate the effects of simulated microgravity on the autonomic nervous response of the perfused mesenteric vascular bed (MVB), vas deferens and the colon and duodenum from 2-week HU rats. 3. In MVB preparations of HU rats, the frequency-dependent increases in perfusion pressure with perivascular nerve stimulation (PNS; 8-40 Hz) were inhibited, whereas the noradrenaline (NA) concentration-dependent (1-100 microM) perfusion pressure increases were potentiated. The latter most probably reflected up-regulation of alpha-adrenergic receptor function. Relaxant responses of NA-precontracted MVB to PNS (4-30 Hz) or isoprenaline were not different between control and HU preparations, while vasodilation induced by the endothelial agonist ACh was reduced. 4. Transmural stimulation (2-40 Hz) induced frequency-dependent twitches of the vas deferens which were reduced in vas deferens of HU rats, while the sensitivity to NA-induced contraction was significantly increased. 5. In the gastroenteric system of HU rat, direct contractile responses to carbachol or tachykinin as well as relaxant or contractile responses to nervous stimulation appeared unchanged both in the proximal colon rings and in duodenal longitudinal strips. 6. In conclusion, HU treatment affects peripheral tissues in which the main contractile mediators are the adrenergic ones such as resistance vessels and vas deferens, probably by reducing the release of neuromediator. This study validates NA signalling impairment as a widespread process in microgravity, which may most dramatically result in the clinical phenotype of orthostatic intolerance.
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Affiliation(s)
- G De Salvatore
- Dipartimento di Farmacologia e Fisiologia Umana, Facoltà di Medicine e Chirurgia, Bari, Italy
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