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Prischich D, Gomila AMJ, Milla‐Navarro S, Sangüesa G, Diez‐Alarcia R, Preda B, Matera C, Batlle M, Ramírez L, Giralt E, Hernando J, Guasch E, Meana JJ, Villa P, Gorostiza P. Adrenergic Modulation With Photochromic Ligands. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010553] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Davia Prischich
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Alexandre M. J. Gomila
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | | | - Gemma Sangüesa
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Rebeca Diez‐Alarcia
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Beatrice Preda
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Carlo Matera
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Montserrat Batlle
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Laura Ramírez
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
| | - Ernest Giralt
- Department of Inorganic and Organic Chemistry University of Barcelona (UB) Barcelona Spain
- Institute for Research in Biomedicine (IRB) Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Jordi Hernando
- Departament de Química Universitat Autònoma de Barcelona (UAB) Cerdanyola del Vallès Spain
| | - Eduard Guasch
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - J. Javier Meana
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Pedro Villa
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) Madrid Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
- Catalan Institution for Research and Advanced Studies (ICREA) Barcelona Spain
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Prischich D, Gomila AMJ, Milla‐Navarro S, Sangüesa G, Diez‐Alarcia R, Preda B, Matera C, Batlle M, Ramírez L, Giralt E, Hernando J, Guasch E, Meana JJ, Villa P, Gorostiza P. Adrenergic Modulation With Photochromic Ligands. Angew Chem Int Ed Engl 2020; 60:3625-3631. [DOI: 10.1002/anie.202010553] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/21/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Davia Prischich
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Alexandre M. J. Gomila
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | | | - Gemma Sangüesa
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Rebeca Diez‐Alarcia
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Beatrice Preda
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Carlo Matera
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Montserrat Batlle
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Laura Ramírez
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
| | - Ernest Giralt
- Department of Inorganic and Organic Chemistry University of Barcelona (UB) Barcelona Spain
- Institute for Research in Biomedicine (IRB) Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Jordi Hernando
- Departament de Química Universitat Autònoma de Barcelona (UAB) Cerdanyola del Vallès Spain
| | - Eduard Guasch
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - J. Javier Meana
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Pedro Villa
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) Madrid Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
- Catalan Institution for Research and Advanced Studies (ICREA) Barcelona Spain
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An additional physiological role for HSP70: Assistance of vascular reactivity. Life Sci 2020; 256:117986. [PMID: 32585245 DOI: 10.1016/j.lfs.2020.117986] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/09/2020] [Accepted: 06/16/2020] [Indexed: 11/20/2022]
Abstract
AIMS HSP70, a molecular chaperone, helps to maintain proteostasis. In muscle biology, however, evidence suggests HSP70 to have a more versatile range of functions, as genetic deletion of its inducible genes impairs Ca2+ handling, and consequently, cardiac and skeletal muscle contractility. Still, it is unknown whether HSP70 is involved in vascular reactivity, an intrinsic physiological mechanism of blood vessels. Therefore, we designed this study to test the hypothesis that proper vascular reactivity requires the assistance of HSP70. MAIN METHODS We performed functional studies in a wire-myograph using thoracic aorta isolated from male Sprague Dawley rats. Experiments were conducted with and without an HSP70 inhibitor as well as in heat-stressed vessels. The expression levels of HSP70 were evaluated with Western blotting. NO and ROS levels were assessed with fluorescence microscopy. KEY FINDINGS We report that blockade of HSP70 weakens contraction in response to phenylephrine (dose-response) in the aorta. Additionally, we demonstrated that inhibition of HSP70 affects the amplitude of the fast and of the slow components of the time-force curve. Corroborating these findings, we found that inhibition of HSP70, in vessels over-expressing this protein, partly rescues the contractile phenotype of aortic rings. Furthermore, we show that blockade of HSP70 facilitates relaxation in response to acetylcholine and clonidine without affecting the basal levels of NO and ROS. SIGNIFICANCE Our work introduces an additional physiological role for HSP70, the assistance of vascular reactivity, which highlights this protein as a new player in vascular physiology, and therefore, uncovers a promising research avenue for vascular diseases.
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Xu B, Bobek G, Makris A, Hennessy A. Antihypertensive methyldopa, labetalol, hydralazine, and clonidine reversed tumour necrosis factor-α inhibited endothelial nitric oxide synthase expression in endothelial-trophoblast cellular networks. Clin Exp Pharmacol Physiol 2017; 44:421-427. [PMID: 27998008 DOI: 10.1111/1440-1681.12712] [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: 06/23/2016] [Revised: 12/08/2016] [Accepted: 12/11/2016] [Indexed: 11/29/2022]
Abstract
Medications used to control hypertension in pregnancy also improve trophoblast and endothelial cellular interaction in vitro. Tumour necrosis factor-α (TNF-α) inhibits trophoblast and endothelial cellular interactions and simultaneously decreases endothelial nitric oxide synthase (eNOS) expression. This study investigated whether antihypertensive medications improved these cellular interactions by modulating eNOS and inducible nitric oxide synthase (iNOS) expression. Human uterine myometrial microvascular endothelial cells (UtMVECs) were pre-incubated with (or without) low dose TNF-α (0.5 ng/mL) or TNF-α plus soluble fms-like tyrosine kinase-1 (sFlt-1) (100 ng/mL). The endothelial cells were cultured on Matrigel. After endothelial cellular networks appeared, trophoblast derived HTR-8/SVneo cells were co-cultured in the presence of clinically relevant doses of methyldopa, labetalol, hydralazine or clonidine for 24 hours. Cells were retrieved from the Matrigel to extract mRNA and eNOS and iNOS expression were examined by quantitative PCR. Methyldopa, labetalol, hydralazine and clonidine reversed the inhibitory effect of TNF-α on eNOS mRNA expression. After pre-incubating endothelial cells with TNF-α and sFlt-1, all the medications except methyldopa lost their effect on eNOS mRNA expression. In the absence of TNF-α, antihypertensive medications did not change eNOS expression. The mRNA expression of iNOS was not affected by TNF-α or any medications. This study shows that selected antihypertensive medications used in the treatment of hypertension in pregnancy increase eNOS expression in vitro when induced by the inflammatory TNF-α. The anti-angiogenic molecule sFlt-1 may antagonise the potential benefit of these medications by interfering with the NOS pathway.
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Affiliation(s)
- Bei Xu
- School of Medicine, Western Sydney University, Sydney, NSW, Australia.,Vascular Immunology Research Laboratory, The Heart Research Institute, University of Sydney, Sydney, NSW, Australia
| | - Gabriele Bobek
- School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Angela Makris
- School of Medicine, Western Sydney University, Sydney, NSW, Australia.,Vascular Immunology Research Laboratory, The Heart Research Institute, University of Sydney, Sydney, NSW, Australia.,Renal Unit, Liverpool Hospital, Sydney, NSW, Australia
| | - Annemarie Hennessy
- School of Medicine, Western Sydney University, Sydney, NSW, Australia.,Vascular Immunology Research Laboratory, The Heart Research Institute, University of Sydney, Sydney, NSW, Australia
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Couto GK, Davel AP, Brum PC, Rossoni LV. Double disruption of α2A- and α2C-adrenoceptors induces endothelial dysfunction in mouse small arteries: role of nitric oxide synthase uncoupling. Exp Physiol 2014; 99:1427-38. [DOI: 10.1113/expphysiol.2014.079236] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Gisele K. Couto
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo SP Brazil
| | - Ana P. Davel
- Department of Structural and Functional Biology; Institute of Biology; State University of Campinas; Campinas SP Brazil
| | - Patrícia C. Brum
- School of Physical Education and Sport; University of São Paulo; São Paulo SP Brazil
| | - Luciana V. Rossoni
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo SP Brazil
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6
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Dantas da Silva Júnior E, Palmieri de Souza B, Quintella Dantas Rodrigues J, Caricati-Neto A, Jurkiewicz A, Jurkiewicz NH. Effects of clonidine in the isolated rat testicular capsule. Eur J Pharmacol 2014; 726:16-26. [DOI: 10.1016/j.ejphar.2014.01.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 12/18/2013] [Accepted: 01/12/2014] [Indexed: 11/30/2022]
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7
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Tagashira H, Matsumoto T, Taguchi K, Zhang C, Han F, Ishida K, Nemoto S, Kobayashi T, Fukunaga K. Vascular endothelial σ1-receptor stimulation with SA4503 rescues aortic relaxation via Akt/eNOS signaling in ovariectomized rats with aortic banding. Circ J 2013; 77:2831-40. [PMID: 23965801 DOI: 10.1253/circj.cj-13-0256] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND We previously reported that σ1-receptor (σ1R) expression in the thoracic aorta decreased after pressure overload (PO) induced by abdominal aortic banding in ovariectomized (OVX) rats. Here, we asked whether stimulation of σ1R with the selective agonist SA4503 elicits functional recovery of aortic vasodilation and constriction following vascular injury in OVX rats with PO. METHODS AND RESULTS SA4503 (0.3-1.0mg/kg) and NE-100 (a σ1R antagonist, 1.0mg/kg) were administered orally for 4 weeks (once daily) to OVX-PO rats. Vascular functions of isolated descending aorta were measured following phenylephrine (PE)- or endothelin-1 (ET-1)-induced vasoconstriction and acetylcholine (ACh)- or clonidine-induced vasodilation. SA4503 administration rescued PO-induced σ1R decreases in aortic smooth muscle and endothelial cells. SA4503 treatment also rescued PO-induced impairments in ACh- and clonidine-induced vasodilation without affecting PE- and ET-1-induced vasoconstriction. Ameliorated ACh- and clonidine-induced vasodilation was closely associated with increased Akt activity and in turn endothelial nitric oxide synthase (eNOS) phosphorylation. The SA4503-mediated improvement of vasodilation was blocked by NE-100 treatment. CONCLUSIONS σ1R is downregulated following PO-induced endothelial injury in OVX rats. The selective σ1R agonist SA4503 rescues impaired endothelium-dependent vasodilation in the aorta from OVX-PO rats through σ1R stimulation, enhancing eNOS-cGMP signaling in vascular endothelial cells. These observations encourage development of novel therapeutics targeting σ1R to prevent vascular endothelial injury in vascular diseases.
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MESH Headings
- Adrenergic alpha-1 Receptor Agonists/pharmacology
- Animals
- Anisoles/pharmacology
- Antipsychotic Agents/pharmacology
- Aorta, Abdominal/injuries
- Aorta, Abdominal/metabolism
- Aorta, Abdominal/pathology
- Aortic Diseases/metabolism
- Aortic Diseases/pathology
- Cyclic GMP/metabolism
- Endothelin-1/pharmacology
- Endothelium, Vascular/injuries
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Female
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Nitric Oxide Synthase Type III/metabolism
- Nootropic Agents/pharmacology
- Ovariectomy
- Phenylephrine/pharmacology
- Phosphorylation/drug effects
- Piperazines/pharmacology
- Propylamines/pharmacology
- Proto-Oncogene Proteins c-akt/metabolism
- Rats, Wistar
- Receptors, sigma/agonists
- Receptors, sigma/metabolism
- Vasodilation/drug effects
- Sigma-1 Receptor
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Affiliation(s)
- Hideaki Tagashira
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University
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8
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Enouri S, Monteith G, Johnson R. Functional characteristics of alpha adrenergic and endothelinergic receptors in pressurized rat mesenteric veins. Can J Physiol Pharmacol 2013; 91:538-46. [DOI: 10.1139/cjpp-2012-0079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Increasing transmural pressure can alter the functional role of post-junctional receptor subtypes. Under conditions of changing transmural pressure, we investigated the relative contributions of alpha adrenergic (α-ARs) and endothelinergic receptors to norepinephrine (NE) and endothelin (ET-1) contractile responses, respectively, in third-order rat mesenteric small veins (MSV) and arteries (MSA). NE, phenylephrine (PE), clonidine, and ET-1 concentration–response curves were constructed in the absence and presence of α-adrenergic and ET-1 receptor antagonists, respectively. MSV were more sensitive to NE, PE, and ET-1 compared with MSA. The sensitivity of MSV to NE was higher than that to PE. Phentolamine (α1-AR/α2-AR antagonist) and prazosin (α1-AR antagonist) completely abolished NE responses. Yohimbine (α2-AR antagonist) reduced NE and clonidine contractile responses in MSV. Clonidine contractile responses were reduced by prazosin in MSA. In MSA and MSV, BQ-610 (ETA receptor antagonist) but not BQ-788 (ETB receptor antagonist) reduced ET-1 contractile responses. Combined application of BQ-610 and BQ-788 caused further reduction in ET-1 concentration–response curves obtained in MSV. These results suggest that in addition to α1-ARs and ETA receptors, α2-ARs and ETB receptors also mediate NE and ET-1 contractile responses in MSV, respectively, with no change in the participation of these receptors as transmural pressure is increased.
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Affiliation(s)
- Saad Enouri
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Gabrielle Monteith
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Ron Johnson
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
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Contribution of α-Adrenoceptor Stimulation by Phenylephrine to Basal Nitric Oxide Production in the Isolated Mouse Aorta. J Cardiovasc Pharmacol 2013; 61:318-23. [DOI: 10.1097/fjc.0b013e318281fa2d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Interaminense LDFL, dos Ramos-Alves FE, de Siqueira RJB, Xavier FE, Duarte GP, Magalhães PJC, Maia JGS, Sousa PJDC, Lahlou S. Vasorelaxant effects of 1-nitro-2-phenylethane, the main constituent of the essential oil of Aniba canelilla, in superior mesenteric arteries from spontaneously hypertensive rats. Eur J Pharm Sci 2013; 48:709-16. [PMID: 23313621 DOI: 10.1016/j.ejps.2012.12.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 12/25/2012] [Accepted: 12/30/2012] [Indexed: 10/27/2022]
Abstract
The present study investigated the mechanisms underlying the vasorelaxant effects of the essential oil of Aniba canelilla (EOAC) and its main constituent 1-nitro-2-phenylethane (NP) in isolated superior mesenteric artery from spontaneously hypertensive rats (SHRs). At 0.1-1000 μg/mL, EOAC and NP relaxed SMA preparations pre-contracted with 75 mMKCl with IC(50) (geometric mean [95% confidence interval]) values of 294.19 [158.20-94.64] and 501.27 [378.60-624.00] μg/mL, respectively); or with phenylephrine (PHE) (IC(50)s=11.07 [6.40-15.68] and 7.91 [4.08-11.74) μg/mL, respectively). All these effects were reversible and remained unaltered by vascular endothelium removal. In preparations maintained under Ca(2+)-free conditions, EOAC and NP (both at 600 μg/mL) reduced the PHE-, but not the caffeine-induced contraction. In Ca(2+)-free and high K(+) (75 mM) medium, the contractions produced by CaCl(2) or BaCl(2) were reduced or even abolished by EOAC and NP at 100 and 600 μg/mL, respectively. EOAC and NP (both at 10-1000 μg/mL) also relaxed the contraction evoked by phorbol dibutyrate (IC(50)=52.66 [10.82-94.64] and 39.13 [31.55-46.72] μg/mL, respectively). It is concluded that NP has a myogenic endothelium-independent vasorelaxant effects and appears to be the active principle of the EOAC. Vasorelaxant effect induced by both EOAC and NP is preferential to receptor-activated pathways and it appears to occur intracellularly more than a superficial action restricted to the membrane environment such as a simple blocking activity on a given receptor or ion channel.
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11
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Chalkiadis GA, Abdullah F, Bjorksten AR, Clarke A, Cortinez LI, Udayasiri S, Anderson BJ. Absorption characteristics of epidural levobupivacaine with adrenaline and clonidine in children. Paediatr Anaesth 2013; 23:58-67. [PMID: 23167288 DOI: 10.1111/pan.12074] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/27/2012] [Indexed: 01/24/2023]
Abstract
AIM To determine if the addition of adrenaline, clonidine, or their combination altered the pharmacokinetic profile of levobupivacaine administered via the caudal epidural route in children. METHODS Children aged <18 years old scheduled to undergo sub-umbilical surgery were administered caudal levobupivacaine plain 2.5 mg · ml(-1) or with adjuvants adrenaline 5 mcg · ml(-1) or clonidine 2 mcg · ml(-1) or their combination. Covariate analysis included weight and postnatal age (PNA). Time-concentration profile analysis was undertaken using nonlinear mixed effects models. A one-compartment linear disposition model with first-order input and first-order elimination was used to describe the data. The effect of either clonidine or adrenaline on absorption was investigated using a scaling parameter (Fabs(CLON), Fabs(ADR)) applied to the absorption half-life (Tabs). RESULTS There were 240 children (median weight 11.0, range 1.9-56.1 kg; median postnatal age 16.7, range 0.6-167.6 months). Absorption of levobupivacaine was faster when mixed with clonidine (Fabs(CLON) 0.60; 95%CI 0.44, 0.83) but slower when mixed with adrenaline (Fabs(ADR) 2.12; 95%CI 1.45, 3.08). The addition of adrenaline to levobupivacaine resulted in a bifid absorption pattern. While initial absorption was unchanged (Tabs 0.15 h 95%CI 0.12, 0.18 h), there was a late absorption peak characterized by a Tabs(LATE) 2.34 h (95%CI 1.44, 4.97 h). The additional use of clonidine with adrenaline had minimal effect on the bifid absorption profile observed with adrenaline alone. Neither clonidine nor adrenaline had any effect on clearance. The population parameter estimate for volume of distribution was 157 l 70 kg(-1). Clearance was 6.5 l · h(-1) 70 kg(-1) at 1-month PNA and increased with a maturation half-time of 1.6 months to reach 90% of the mature value (18.5 l · h(-1) 70 kg(-1)) by 5 months PNA. CONCLUSIONS The addition of adrenaline decreases the rate of levobupivacaine systemic absorption, reducing peak concentration by half. Levobupivacaine concentrations with adrenaline adjuvant were reduced compared to plain levobupivacaine for up to 3.5 hours. Clonidine as an adjuvant results in faster systemic absorption of levobupivacaine and similar concentration time profile to levobupivacaine alone. Adding adrenaline with clonidine does not alter the concentration profile observed with adrenaline alone.
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Affiliation(s)
- George A Chalkiadis
- Department of Paediatric Anaesthesia and Pain Management, Royal Children's Hospital, Parkville, Victoria, Australia.
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12
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Gourdin M, Dubois P, Mullier F, Chatelain B, Dogné JM, Marchandise B, Jamart J, De Kock M. The Effect of Clonidine, an Alpha-2 Adrenergic Receptor Agonist, on Inflammatory Response and Postischemic Endothelium Function During Early Reperfusion in Healthy Volunteers. J Cardiovasc Pharmacol 2012; 60:553-60. [DOI: 10.1097/fjc.0b013e31827303fa] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Abstract
Anaesthesia dosing in infants (0-2 years) should be based on pharmacokinetic-pharmacodynamic considerations and adverse effects profiles. Disease processes and treatments in this group are distinct from those in adults. Absorption, distribution and clearance change dramatically during this period because of maturation of anatomical and physiological processes as well as behavioural changes. Pharmacogenomic expression also matures in this period. Population-based and physiological-based pharmacokinetic modelling has improved the understanding of maturation and subsequent dose approximation. Postmenstrual, rather than postnatal, age is a reasonable measure for maturation. There remains a need for clinically applicable tools to assess pharmacodynamics which can provide response feedback; this has been achieved for neuromuscular monitoring, but not yet fully for depth of anaesthesia, sedation or pain. Morbidity and mortality associated with paediatric anaesthesia have historically been highest in this age group and continue to be so. Some of this morbidity was attributable to a poor understanding of developmental pharmacology; this facet continues to plague the specialty.
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14
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Kim JG, Sung HJ, Ok SH, Kwon SC, Cheon KS, Kim HJ, Chang KC, Shin IW, Lee HK, Chung YK, Sohn JT. Calcium sensitization involved in dexmedetomidine-induced contraction of isolated rat aorta. Can J Physiol Pharmacol 2011; 89:681-9. [DOI: 10.1139/y11-065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Dexmedetomidine, a full agonist of the α2B-adrenoceptor that is mainly involved in vascular smooth muscle contraction, is primarily used for analgesia and sedation in intensive care units. High-dose dexmedetomidine produces hypertension in children and adults. The goal of this in vitro study was to investigate the role of the calcium (Ca2+) sensitization mechanism involving Rho-kinase, protein kinase C (PKC), and phosphoinositide 3-kinase (PI3-K) in mediating contraction of isolated rat aortic smooth muscle in response to dexmedetomidine. The effect of dexmedetomidine on the intracellular Ca2+ level ([Ca2+]i) and tension was measured simultaneously. Dexmedetomidine concentration–response curves were generated in the presence or absence of the following antagonists: rauwolscine, Y 27632, LY 294002, GF 109203X, and verapamil. Dexmedetomidine-induced phosphorylation of PKC and membrane translocation of Rho-kinase were detected with Western blotting. Rauwolscine, Y 27632, GF 109203X, LY 294002, and verapamil attenuated dexmedetomidine-induced contraction. The slope of the [Ca2+]i–tension curve for dexmedetomidine was higher than that for KCl. Dexmedetomidine induced phosphorylation of PKC and membrane translocation of Rho-kinase. These results suggest that dexmedetomidine-induced contraction involves a Ca2+ sensitization mechanism mediated by Rho-kinase, PKC, and PI3-K that is secondary to α2-adrenoceptor stimulation in rat aortic smooth muscle.
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Affiliation(s)
- Jae-Gak Kim
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju 660-702, Korea
| | - Hui-Jin Sung
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju 660-702, Korea
| | - Seong-Ho Ok
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju 660-702, Korea
| | - Seong-Chun Kwon
- Department of Physiology, Kwandong University College of Medicine, Kangneung 201-701, Korea
| | - Kwang Seong Cheon
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju 660-702, Korea
| | - Hye Jung Kim
- Department of Pharmacology, Gyeongsang National University School of Medicine, Jinju 660-772, Korea
| | - Ki Churl Chang
- Department of Pharmacology, Gyeongsang National University School of Medicine, Jinju 660-772, Korea
| | - Il-Woo Shin
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju 660-702, Korea
| | - Heon-Keun Lee
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju 660-702, Korea
| | - Young-Kyun Chung
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju 660-702, Korea
| | - Ju-Tae Sohn
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju 660-702, Korea
- Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 660-702, Korea
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15
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Fonseca-Magalhães PA, Sousa DF, de Siqueira RJB, Jorge RJB, Meneses GC, Alves RS, Monteiro HSA, Magalhães PJC, Martins AMC. Inhibitory effects of sertraline in rat isolated perfused kidneys and in isolated ring preparations of rat arteries. J Pharm Pharmacol 2011; 63:1186-94. [DOI: 10.1111/j.2042-7158.2011.01317.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Abstract
Objectives
Sertraline is often prescribed to patients suffering with end stage renal disease, but its action on kidney has not been investigated. We aimed to investigate the pharmacological action of sertraline on rat kidney with emphasis on the underlying mechanisms involved in the vascular actions of the drug.
Methods
The effects of sertraline were evaluated in rat isolated perfused kidneys and on ring preparations of mesenteric or segmental rat renal artery.
Key findings
In kidneys, sertraline prevented the effects of phenylephrine on perfusion pressure, glomerular filtration rate, urinary flow and renal vascular resistance. In mesenteric rings sertraline inhibited phenylephrine-induced contractions with potency 30-times lower than verapamil. Sertraline reversed sustained contractions induced by phenylephrine or 60 mm K+ within a similar concentration range. In segmental isolated rings, sertraline also reversed contractions induced by phenylephrine or 60 mm K+ with the same concentration range, but with higher potency compared with mesenteric preparations. Under Ca2+-free conditions, sertraline did not change the intracellularly-mediated phasic contractions induced by phenylephrine or caffeine. Sertraline was ineffective against contractions induced by extracellular Ca2+ restoration after thapsigargin treatment and Ca2+ store depletion with phenylephrine. Conversely, sertraline decreased the contractions induced by Ca2+ addition in tissues under high K+ solution or phenylephrine plus verapamil.
Conclusions
In rat isolated kidneys and in rat ring preparations of mesenteric or renal vessels, sertraline had antispasmodic effects that appeared to be caused by a direct action on vascular smooth muscle cells. Its actions were ineffective against Ca2+-releasing intracellular pathways, but appeared to interfere with sarcolemmal Ca2+ influx with reduced permeability of both receptor- and voltage-gated Ca2+ channels.
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Affiliation(s)
| | - Daniel F Sousa
- Departamento de Fisiologia e Farmacologia, Ceará, Brasil
| | | | | | - Gdayllon C Meneses
- Análises Clínicas e Toxicológicas, Universidade Federal do Ceará, Ceará, Brasil
| | - Renata S Alves
- Análises Clínicas e Toxicológicas, Universidade Federal do Ceará, Ceará, Brasil
| | | | | | - Alice M C Martins
- Análises Clínicas e Toxicológicas, Universidade Federal do Ceará, Ceará, Brasil
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16
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Ok SH, Jeong YS, Kim JG, Lee SM, Sung HJ, Kim HJ, Chang KC, Kwon SC, Sohn JT. c-Jun NH₂-terminal kinase contributes to dexmedetomidine-induced contraction in isolated rat aortic smooth muscle. Yonsei Med J 2011; 52:420-8. [PMID: 21488184 PMCID: PMC3101051 DOI: 10.3349/ymj.2011.52.3.420] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PURPOSE Dexmedetomidine, a full agonist of α2B-adrenoceptors, is used for analgesia and sedation in the intensive care units. Dexmedetomidine produces an initial transient hypertension due to the activation of post-junctional α2B-adrenoceptors on vascular smooth muscle cells (SMCs). The aims of this in vitro study were to identify mitogen-activated protein kinase (MAPK) isoforms that are primarily involved in full, α2B-adrenoceptor agonist, dexmedetomidine-induced contraction of isolated rat aortic SMCs. MATERIALS AND METHODS Rat thoracic aortic rings without endothelium were isolated and suspended for isometric tension recording. Cumulative dexmedetomidine (10⁻⁹ to 10⁻⁶ M) dose-response curves were generated in the presence or absence of extracellular signal-regulated kinase (ERK) inhibitor PD 98059, p38 MAPK inhibitor SB 203580, c-Jun NH₂-terminal kinase (JNK) inhibitor SP 600125, L-type calcium channel blocker (verapamil and nifedipine), and α₂-adrenoceptor inhibitor atipamezole. Dexmedetomidine-induced phosphorylation of ERK, JNK, and p38 MAPK in rat aortic SMCs was detected using Western blotting. RESULTS SP 600125 (10⁻⁶ to 10⁻⁵ M) attenuated dexmedetomidine-evoked contraction in a concentration- dependent manner, whereas PD 98059 had no effect on dexmedetomidine- induced contraction. SB 203580 (10⁻⁵ M) attenuated dexmedetomidine-induced contraction. Dexmedetomidine-evoked contractions were both abolished by atipamezole and attenuated by verapamil and nifedipine. Dexmedetomidine induced phosphorylation of JNK and p38 MAPK in rat aortic SMCs, but did not induce phosphorylation of ERK. CONCLUSION Dexmedetomidine-induced contraction involves a JNK- and p38 MAPK-mediated pathway downstream of α₂-adrenoceptor stimulation in rat aortic SMCs. In addition, dexmedetomidine-induced contractions are primarily dependent on calcium influx via L-type calcium channels.
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Affiliation(s)
- Seong-Ho Ok
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju, Korea
| | - Young Seok Jeong
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju, Korea
| | - Jae-Gak Kim
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju, Korea
| | - Seung-Min Lee
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju, Korea
| | - Hui-Jin Sung
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju, Korea
| | - Hye Jung Kim
- Department of Pharmacology, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Ki Churl Chang
- Department of Pharmacology, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Seong-Chun Kwon
- Department of Physiology, Kwandong University College of Medicine, Kangneung, Korea
| | - Ju-Tae Sohn
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University School of Medicine, Jinju, Korea
- Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
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17
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Prehypoxic clonidine administration improves vasomotricity of isolated rat aorta during reoxygenation. Eur J Anaesthesiol 2010; 27:965-72. [DOI: 10.1097/eja.0b013e32833b001c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Cankar K, Finderle Ž, Štrucl M. The effect of α-adrenoceptor agonists and L-NMMA on cutaneous postocclusive reactive hyperemia. Microvasc Res 2009; 77:198-203. [DOI: 10.1016/j.mvr.2008.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Revised: 09/29/2008] [Accepted: 10/27/2008] [Indexed: 11/17/2022]
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19
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Analysis of the mechanisms underlying the endothelium-dependent antivasoconstriction of puerarin in rat aorta. Naunyn Schmiedebergs Arch Pharmacol 2009; 379:587-97. [DOI: 10.1007/s00210-008-0388-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Accepted: 12/21/2008] [Indexed: 11/25/2022]
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20
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Kim HJ, Sohn JT, Jeong YS, Cho MS, Kim HJ, Chang KC, Shin MK, Park CS, Chung YK. Direct effect of dexmedetomidine on rat isolated aorta involves endothelial nitric oxide synthesis and activation of the lipoxygenase pathway. Clin Exp Pharmacol Physiol 2008; 36:406-12. [PMID: 19018801 DOI: 10.1111/j.1440-1681.2008.05082.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1. The aims of the present in vitro study were to examine the roles of pathways associated with arachidonic acid metabolism in dexmedetomidine-induced contraction and to determine which endothelium-derived vasodilators are involved in the endothelium-dependent attenuation of vasoconstriction elicited by dexmedetomidine. 2. Dexmedetomidine (10(-9)-10(-6) mol/L) concentration-response curves were constructed in: (i) aortic rings with no drug pretreatment; (ii) endothelium-denuded aortic rings pretreated with either 2 x 10(-5) mol/L quinacrine dihydrochloride, 10(-5) mol/L nordihydroguaiaretic acid (NDGA), 3 x 10(-5) mol/L indomethacin or 10(-5) mol/L fluconazole; and (iii) endothelium-intact aortic rings pretreated with either 5 x 10(-5) mol/L N(G)-nitro-l-arginine methyl ester (l-NAME), 10(-5) mol/L fluconazole, 10(-5) mol/L indomethacin, 10(-5) mol/L glibenclamide, 5 x 10(-3) mol/L tetraethylammonium or 5 x 10(-5) mol/L l-NAME plus rauwolscine (10(-5), 10(-6) mol/L). The production of nitric oxide (NO) metabolites was determined in human umbilical vein endothelial cells treated with dexmedetomidine. 3. Quinacrine dihydrochloride, NDGA and indomethacin attenuated the dexmedetomidine-induced contraction of endothelium-denuded rings. Dexmedetomidine (10(-7)-10(-6) mol/L)-induced contractions of endothelium-denuded rings were enhanced compared with those of endothelium-intact rings, as were dexmedetomidine-induced contractions of endothelium-intact rings pretreated with l-NAME or tetraethylammonium. Rauwolscine attenuated dexmedetomidine-induced contractions in endothelium-intact rings pretreated with l-NAME. Dexmedetomidine (10(-6) mol/L) was found to activate NO production. 4. Taken together, the results indicate that dexmedetomidine-induced contraction of aortic rings involves activation of the lipoxygenase and cyclo-oxygenase pathways and is attenuated by increased NO production following stimulation of endothelial alpha(2)-adrenoceptors by dexmedetomidine.
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Affiliation(s)
- Hee-Jin Kim
- Department of Anaesthesiology and Pain Medicine, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
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21
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The effects of nitric oxide donors on the sporulation of Eimeria tenella oocysts. Vet Parasitol 2008; 154:336-40. [DOI: 10.1016/j.vetpar.2008.03.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Revised: 03/20/2008] [Accepted: 03/27/2008] [Indexed: 12/27/2022]
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22
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Endothelial nitric oxide attenuates Na+/Ca2+ exchanger-mediated vasoconstriction in rat aorta. Br J Pharmacol 2008; 154:982-90. [PMID: 18469841 DOI: 10.1038/bjp.2008.178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE The Na+/Ca2+ exchanger (NCX) may be an important modulator of Ca2+ entry and exit. The present study investigated whether NCX was affected by prostacyclin and nitric oxide (NO) released from the vascular endothelium, as NCX contains phosphorylation sites for PKA and PKG. EXPERIMENTAL APPROACH Rat aortic rings were set up in organ baths. Tension was measured across the ring with a force transducer. KEY RESULTS Lowering extracellular [Na+] ([Na+]o) to 1.18 mM induced vasoconstriction in rat endothelium-denuded aortic rings. This effect was blocked by the NCX inhibitor KB-R7943 (2-2-[4-(4-nitrobenzyloxy)phenyl] ethyl isothiourea methanesulphonate; 1 microM). In endothelium-intact aortic rings, decreasing [Na+]o did not constrict the aortic rings significantly, but after treatment with the guanylate cyclase inhibitor ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one; 1 microM) or the NOS inhibitor L-NAME (N(omega)-nitro-L-arginine methyl ester; 50 microM), a vasoconstriction that was similar in size to that in endothelium-denuded preparations was evident. The vasorelaxation induced by the NO donor sodium nitroprusside sodium nitroprusside dihydrate (30 nM) was the same in the endothelium-denuded aortic rings preconstricted with either low Na+ (1.18 mM), the thromboxane A2 agonist U46619 (9,11-dideoxy-9alpha, 11alpha-methanoepoxy prostaglandin F(2alpha); 0.1 microM) or high K+ (80 mM). CONCLUSIONS AND IMPLICATIONS The results suggest that the endothelium inhibits NCX operation via guanylate cyclase/NO. This is stronger than for other constrictors such as phenylephrine and may relate to concomitant NCX-stimulated NO release from the endothelium. This finding may be important where NCX operates in reverse mode, such as during ischaemia, and highlights a new mechanism whereby the endothelium modulates Ca2+ homoeostasis in vascular smooth muscle.
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23
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Pimentel AML, Costa CA, Carvalho LCRM, Brandão RM, Rangel BM, Tano T, Soares de Moura R, Resende AC. The role of NO-cGMP pathway and potassium channels on the relaxation induced by clonidine in the rat mesenteric arterial bed. Vascul Pharmacol 2006; 46:353-9. [PMID: 17258511 DOI: 10.1016/j.vph.2006.12.003] [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: 11/25/2006] [Revised: 11/25/2006] [Accepted: 12/05/2006] [Indexed: 10/23/2022]
Abstract
The mechanisms involved in the vasodilation action of clonidine have not yet been completely elucidated. We investigated the potential mechanisms that seem to be involved in the clonidine vasodilator effect using rat isolated mesenteric arterial bed (MAB). In precontracted MAB, clonidine (10-300 pmol) induced a dose-dependent relaxation, that was inhibited by endothelium removal (deoxycholic acid - 2.5 mM) and reduced by the alpha(2) adrenoceptor inhibitors yohimbine (1-3 microM) and rauwolscine (1 microM). The endothelium-dependent vasodilation induced by clonidine was reduced by the nitric oxide (NO) synthase inhibitor L-NAME (0.3 mM) and guanylyl cyclase inhibitor ODQ (10 microM) but was not affected by indomethacin (3-10 microM) alone. High K+ (25 mM) solution reduced the vasodilator effect of clonidine that was further attenuated by L-NAME. In the presence of high K+ plus L-NAME, the residual vasodilator effect of clonidine was further reduced by indomethacin (3 microM). The Ca(2+)-dependent K+ channel (K+(Ca2+)) inhibitors, charybdotoxin (ChTx; 0.1 microM) plus apamin (0.1 microM), also reduced the vasodilation induced by clonidine, however this response was not further reduced in the presence of L-NAME as observed with acetylcholine (10 pmol). In the presence of ATP-dependent K+ channel (K+(ATP)) blocker, glibenclamide (10 microM), the inhibitory effect of ChTx plus apamin plus L-NAME was increased. In contrast, the vasodilation induced by clonidine was not affected by voltage-dependent K+ channels (K(V)) blocker, 4-aminopyridine (4-AP, 1 mM). In conclusion, our results demonstrate that clonidine activates alpha(2)-adrenoceptors in rat MAB and that the endothelium-dependent vasodilation is mediated by activation of NO-cGMP pathway, hyperpolarization due to activation of K+(Ca) and K+(ATP) channels. Prostaglandins might participate in the vasodilator effect of clonidine when NO and EDHF mechanisms are blunted.
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MESH Headings
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic alpha-Antagonists/pharmacology
- Animals
- Biological Factors/metabolism
- Clonidine/pharmacology
- Cyclic GMP/metabolism
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Enzyme Inhibitors/pharmacology
- Guanylate Cyclase/antagonists & inhibitors
- Guanylate Cyclase/metabolism
- In Vitro Techniques
- Male
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Synthase/antagonists & inhibitors
- Nitric Oxide Synthase/metabolism
- Potassium/metabolism
- Potassium Channel Blockers/pharmacology
- Potassium Channels/drug effects
- Potassium Channels/metabolism
- Potassium Channels, Calcium-Activated/drug effects
- Potassium Channels, Calcium-Activated/metabolism
- Prostaglandins/metabolism
- Rats
- Rats, Wistar
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Vasodilation/drug effects
- Vasodilator Agents/pharmacology
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Affiliation(s)
- A M L Pimentel
- Departamento de Farmacologia e Psicobiologia, Instituto de Biologia, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Av. 28 de Setembro 87, Rio de Janeiro, Brazil
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24
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Vidrio H, Carrasco OF, Rodríguez R. Antivasoconstrictor effect of the neuroprotective agent dexrazoxane in rat aorta. Life Sci 2006; 80:98-104. [PMID: 17007888 DOI: 10.1016/j.lfs.2006.08.025] [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] [Received: 05/04/2006] [Revised: 08/17/2006] [Accepted: 08/21/2006] [Indexed: 12/01/2022]
Abstract
Dexrazoxane is used clinically to reduce the cardiotoxicity of anthracycline cancer chemotherapeutic agents, acting by an iron-chelating antioxidant mechanism. In a study designed to explore the possible mechanism of the recently described neuroprotective effect of the drug in cerebral ischemia, its influence on vascular reactivity was determined in rat aortic rings. Dexrazoxane was found to be devoid of direct contractile or relaxant activity and to have no influence on responses to acetylcholine or histamine (relaxation), or to angiotensin or serotonin (contraction). In contrast, it decreased contractions to norepinephrine, as evidenced by rightward displacement of the concentration-response curves. The effect was prevented by the removal of the endothelium and by the alpha(2)-adrenoceptor antagonist yohimbine; it was partially antagonized by the endothelium-derived depolarizing factor inhibitor clotrimazole, but was not affected by L-NAME or indomethacin, inhibitors of endothelial nitric oxide and prostacyclin production. The anti-contractile effect did not occur in rings stimulated with the alpha(1)-adrenoceptor agonist phenylephrine. It was concluded that dexrazoxane opposes norepinephrine vascular contraction by enhancing endothelial alpha(2)-adrenoceptor-mediated release of relaxing factor(s). The drug could thus offset the deleterious vasoconstriction elicited by the increased circulating catecholamines present during cerebral ischemia, and by this mechanism produce neuroprotection.
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MESH Headings
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/physiology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiology
- In Vitro Techniques
- Male
- Molecular Structure
- Neuroprotective Agents/chemistry
- Neuroprotective Agents/pharmacology
- Rats
- Rats, Wistar
- Razoxane/chemistry
- Razoxane/pharmacology
- Receptors, Adrenergic, alpha-2/metabolism
- Vasoconstriction/drug effects
- Vasoconstrictor Agents/pharmacology
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Horacio Vidrio
- Department of Pharmacology, School of Medicine, Universidad Nacional Autónoma de México, Apartado Postal 70297, México City 04510, Mexico, D.F., México.
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25
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Kennedy WB, Crane L, Gonzalez RR, George OK, Edwards LP. Centrally Acting Imidazolines Stimulate Vascular Alpha 1A-Adrenergic Receptors in Rat-Tail Artery. Cell Mol Neurobiol 2006; 26:645-57. [PMID: 16897362 DOI: 10.1007/s10571-006-9109-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Accepted: 06/26/2006] [Indexed: 01/02/2023]
Abstract
: 1. Centrally acting imidazoline antihypertensive agents clonidine and moxonidine also act peripherally to contract blood vessels. While these agents act at both I(1)-imidazoline and alpha 2 adrenergic receptors centrally, the receptor types by which they mediate contraction require further definition. We therefore characterized the receptor subtype by which these agents mediate contraction of proximal rat-tail artery. 2. Dose-response curves were determined for phenylephrine and for several imidazoline ligands, using endothelium denuded, isolated ring segments, of tail arteries from adult male Sprague-Dawley rats. Ring segments were mounted on a force transducer with platinum wires and immersed in a tissue bath containing Krebs solution, to which drugs could be added. Signals were digitized and recorded by a computer. 3. Tail artery contractions expressed as a percent of contraction to 106 mM potassium were phenylephrine (96%), moxonidine (88%), clonidine (52%), and UK14304 (30%). Neither rilmenidine nor harmane caused contraction. Contraction of tail artery to moxonidine or clonidine could be blocked by alpha 1 antagonist urapidil or prazosin, and also by alpha 1A subtype selective antagonist WB4101. Schild plots were generated and a calculated pA2 value of 9.2 for prazosin in the presence of clonidine confirms clonidine as an agonist at alpha 1A receptors in proximal segments of rat-tail artery. 4. Our work suggests that clonidine and moxonidine are promiscuous compounds at micromolar concentrations and that harmane and rilmenidine are more selective compounds for in vivo imidazoline research.
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Affiliation(s)
- Wentsworth B Kennedy
- Department of Pharmacology/Physiology, Loma Linda University, Risley Hall, 110421 Campus Street, Loma Linda, California 92350, USA
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