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Nascimento M, Piran R, Da Costa RM, Giordani MA, Carneiro FS, Aguiar DH, Dias MC, Sugizaki MM, Luvizotto RA, Nascimento AF, Bomfim GF. Hepatic injury induced by thioacetamide causes aortic endothelial dysfunction by a cyclooxygenase-dependent mechanism. Life Sci 2018; 212:168-175. [PMID: 30292829 DOI: 10.1016/j.lfs.2018.09.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/22/2018] [Accepted: 09/30/2018] [Indexed: 02/07/2023]
Abstract
Liver cirrhosis is associated with a wide range of cardiovascular abnormalities including hyperdynamic circulation and cirrhotic cardiomyopathy. The pathogenic mechanisms of these cardiovascular changes are multifactorial and include vascular dysregulations. AIM The present study tested the hypothesis that the systemic vascular hyporesponsiveness in thioacetamide (TAA)-induced liver injury model is dependent on nitric oxide (NO) and cyclooxygenase (COX) derivatives. MAIN METHODS Wistar rats were treated with TAA for eight weeks to induce liver injury. KEY FINDINGS The maximal contractile response in concentration-effect curves to phenylephrine was decreased in aorta from TAA-treated rats, but no differences were found in aorta without endothelium, suggesting an endothelium-dependent mechanism in decreased contractile response. There was no difference in the contractile response with and without L-NAME (N(ω)-nitro-l-arginine methyl ester) in rats with liver injury, showing that the TAA treatment impairs NO synthesis. Pre-incubation of the aorta with indomethacin, a COX-inhibitor, normalized the reduced contractile response to phenylephrine in arteries from TAA group. Also, COX-2 and iNOS (inducible nitric oxide syntase) protein expression was increased in aorta from TAA group compared to control group. Animals submitted to TAA treatment had a reduction in systolic blood pressure. Our findings demonstrated that liver injury induced by TAA caused a decrease in aortic contractile response by a COX-dependent mechanism but not by NO release. Also, it was demonstrated an inflammatory process in the aorta of TAA-treated rats by increased expression of COX-2 and iNOS. SIGNIFICANCE Therefore, there is an essential contribution of COX-2 activation in extra-hepatic vascular dysfunction and inflammation present in cirrhosis induced by TAA.
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Affiliation(s)
- M Nascimento
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - R Piran
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - R M Da Costa
- Department of Physiology, Institute of Health Sciences, Federal University of Goias, Jatai, Brazil
| | - M A Giordani
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - F S Carneiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - D H Aguiar
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - M C Dias
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - M M Sugizaki
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - R A Luvizotto
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - A F Nascimento
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil
| | - G F Bomfim
- Institute of Health Science, Federal University of Mato Grosso, Sinop, MT, Brazil.
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Sauvet F, Florence G, Van Beers P, Drogou C, Lagrume C, Chaumes C, Ciret S, Leftheriotis G, Chennaoui M. Total sleep deprivation alters endothelial function in rats: a nonsympathetic mechanism. Sleep 2014; 37:465-73. [PMID: 24587568 DOI: 10.5665/sleep.3476] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
STUDY OBJECTIVES Sleep loss is suspected to induce endothelial dysfunction, a key factor in cardiovascular risk. We examined whether sympathetic activity is involved in the endothelial dysfunction caused by total sleep deprivation (TSD). DESIGN TWO GROUPS: TSD (24-h wakefulness), using slowly rotating wheels, and wheel control (WC). PARTICIPANTS Seven-month-old male Wistar rats. INTERVENTIONS Pharmacological sympathectomy (reserpine, 5 mg/kg, intraperitoneal), nitric oxide synthase (NOS) inhibition (N (G)-nitro-L-arginine, 20 mg/kg, intraperitoneally 30 min before experiment) and cyclooxygenase (COX) inhibition (indomethacin, 5 mg/kg, intraperitoneally 30 min before experiment). MEASUREMENTS AND RESULTS In protocol 1, changes in heart rate (HR) and blood pressure were continuously recorded in the sympathectomized and non-sympathectomized rats. Blood pressure and HR increased during TSD in non-sympathectomized rats. In protocol 2, changes in skin blood flow (vasodilation) were assessed in the sympathectomized and non-sympathectomized rats using laser-Doppler flowmetry coupled with iontophoretic delivery of acetylcholine (ACh), sodium nitroprusside (SNP), and anodal and cathodal currents. ACh- and cathodal current-induced vasodilations were significantly attenuated after TSD in non-sympathectomized and sympathectomized rats (51% and 60%, respectively). In protocol 3, ACh-induced vasodilation was attenuated after NOS and COX inhibition (66% and 49%, respectively). Cathodal current-induced vasodilation decreased by 40% after COX inhibition. In TSD compared to WC a decrease in ACh-induced vasodilation was still observed after COX inhibition. No changes in SNP- and anodal current-induced vasodilation were detected. CONCLUSION These results demonstrate that total sleep deprivation induces a reduction in endothelial-dependent vasodilation. This endothelial dysfunction is independent of blood pressure and sympathetic activity but associated with nitric oxide synthase and cyclooxygenase pathway alterations.
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Affiliation(s)
- Fabien Sauvet
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Geneviève Florence
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Pascal Van Beers
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Catherine Drogou
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Christophe Lagrume
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Cyrielle Chaumes
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Sylvain Ciret
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Georges Leftheriotis
- University of Angers, Angers, France ; Unité mixte Centre National de la Recherche Scientifique (CNRS) 6214 - Institut National de la Santé et de la Recherche Médicale (INSERM) 771, Angers, France
| | - Mounir Chennaoui
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
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Beraprost sodium attenuates cigarette smoke extract-induced apoptosis in vascular endothelial cells. Mol Biol Rep 2012; 39:10447-57. [PMID: 23053949 DOI: 10.1007/s11033-012-1924-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
Abstract
Apoptosis is now widely recognized as an important part of chronic obstructive pulmonary disease (COPD) pathogenesis. Our previous study demonstrated that a prostacyclin (PGI(2)) analogue (beraprost sodium, BPS) prevented cigarette smoke extract (CSE) induced apoptosis of the pulmonary endothelium in rats. So we determined to clarify the apoptosis of vascular endothelial cells in COPD patient and the role of prostacyclin in the protection against apoptosis in vascular endothelial cells induced by CSE. Surgical specimens were obtained from 12 patients with COPD and 10 controls, and the level of apoptosis, prostacyclin synthase (PGI(2)S) expression and 6-keto-PGF1α (a stable metabolite of PGI(2)) were detected. The apoptotic index (AI), caspase-3 activity, expression of caspase-3 and 6-keto-PGF1α were examined in human umbilical vein endothelial cells (HUVECs) under exposure to varied concentrations of CSE for 24 h as well as under exposure to 2.5 % CSE for varied durations. Then, HUVECs under 2.5 % CSE were exposed to varied concentrations of BPS for 24 h and observed the alteration and the level of cAMP. Increased AI, decreased expression of PGI(2)S and 6-keto-PGF1α, were found in the lungs of patients with COPD compared with controls. Moreover, CSE induced apoptosis in means of both dose-dependent and time-dependent manners, and reduced the level of 6-keto-PGF1α in HUVECs. And with the treatment of BPS, an enhanced level of cAMP and decreased apoptosis were detected. The deficiency of PGI(2) critically contributes to the COPD-associated endothelial dysfunction and apoptosis. And BPS protects against the apoptosis in the vascular endothelial cells induced by CSE.
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Araújo AV, Ferezin CZ, Rodrigues GJ, Lunardi CN, Vercesi JA, Grando MD, Bonaventura D, Bendhack LM. Prostacyclin, not only nitric oxide, is a mediator of the vasorelaxation induced by acetylcholine in aortas from rats submitted to cecal ligation and perforation (CLP). Vascul Pharmacol 2011; 54:44-51. [DOI: 10.1016/j.vph.2010.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 11/06/2010] [Accepted: 12/09/2010] [Indexed: 10/18/2022]
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What Can Current Stimulation Tell Us about the Vascular Function of Endogenous Prostacyclin in Healthy Rat Skin In Vivo? J Invest Dermatol 2011; 131:237-44. [DOI: 10.1038/jid.2010.267] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Additive effect of cyclooxygenase and nitric oxide synthase blockade on the cerebrocortical microcirculation. Neuroreport 2009; 20:1027-31. [DOI: 10.1097/wnr.0b013e32832d6a93] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Merkus D, Houweling B, de Beer VJ, Everon Z, Duncker DJ. Alterations in endothelial control of the pulmonary circulation in exercising swine with secondary pulmonary hypertension after myocardial infarction. J Physiol 2007; 580:907-23. [PMID: 17289783 PMCID: PMC2075461 DOI: 10.1113/jphysiol.2006.127118] [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] [Indexed: 11/08/2022] Open
Abstract
Secondary pulmonary hypertension after myocardial infarction (MI) has been associated with endothelial dysfunction and activation of the endothelin (ET) system. Here, we investigated whether an increased ET-mediated pulmonary vasoconstrictor influence contributes to pulmonary hypertension after MI, and whether this increased ET vasoconstriction is caused by impaired nitric oxide (NO) and prostanoid production. For this purpose, chronically instrumented swine with and without MI ran on a treadmill at 0-4 km h(-1). Mixed ET(A)/ET(B) receptor blockade (tezosentan) was performed in the absence and presence of single or combined inhibition of endothelial NO synthase (eNOS, with N(omega)-nitro-l-arginine) and cyclo-oxygenase (COX, with indometacin). In normal swine, mixed ET(A)/ET(B) blockade decreased pulmonary vascular resistance, but only during exercise. In MI swine, an increased ET-mediated vasoconstrictor influence was observed in the pulmonary circulation both at rest and during exercise. Inhibition of COX resulted in pulmonary vasoconstriction at rest in MI, but not in normal swine; this vasoconstriction in MI swine was normalized by ET(A)/ET(B) receptor blockade. Inhibition of eNOS enhanced the vasodilator response to ET(A)/ET(B) blockade, indicating that NO blunts the pulmonary vasoconstrictor influence of ET. However, this vasodilator response was enhanced to a similar degree in MI and normal swine. In summary, swine with a recent MI are characterized by an exaggerated pulmonary vasoconstrictor influence of ET. This increased ET-mediated pulmonary vasoconstrictor influence is not caused by a loss of NO bioavailability, and is blunted by an increased prostanoid-mediated vasodilatation. In conclusion, an increased ET-mediated vasoconstriction, which does not appear to be the result of loss of endothelial vasodilators, contributes to pulmonary hypertension after MI.
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Affiliation(s)
- Daphne Merkus
- Experimental Cardiology, Thoraxcentre, Cardiovascular Research School COEUR, Erasmus MC, University Medical Centre Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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Nana-Sinkam SP, Lee JD, Sotto-Santiago S, Stearman RS, Keith RL, Choudhury Q, Cool C, Parr J, Moore MD, Bull TM, Voelkel NF, Geraci MW. Prostacyclin prevents pulmonary endothelial cell apoptosis induced by cigarette smoke. Am J Respir Crit Care Med 2007; 175:676-85. [PMID: 17255567 PMCID: PMC1899287 DOI: 10.1164/rccm.200605-724oc] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Impaired endothelial cell-dependent vasodilation, inflammation, apoptosis, and proliferation are manifestations of endothelial dysfunction in chronic obstructive pulmonary disease (COPD). Prostacyclin (PGI(2)) is a major product of the cyclooxygenase pathway with potent vasodilatory and antimitogenic properties and may be relevant to endothelial dysfunction in COPD. OBJECTIVES To determine if PGI(2) expression is altered in smoking-related lung disease and if it may be protective in COPD-associated endothelial dysfunction. METHODS We evaluated, by immunohistochemistry, Western blotting, and polymerase chain reaction, human emphysema tissue compared with normal tissue for expression of prostacyclin synthase (PGI(2)S). We examined the effects of cigarette smoke extract (CSE) and aldehyde components on eicosanoid expression in primary human pulmonary microvascular endothelial cells. Finally, we used a murine model of lung-specific PGI(2)S overexpression and in vitro studies to determine if PGI(2) expression has protective effects on cigarette smoke-induced endothelial apoptosis. MEASUREMENTS AND MAIN RESULTS Human emphysema lung tissue exhibited lower PGI(2)S expression within the pulmonary endothelium than in normal lung. In vitro studies demonstrated that CSE, and in particular the alpha,beta unsaturated aldehyde acrolein, suppressed PGI(2)S gene expression, whereas CSE significantly induced the upstream mediators COX-2 and cytosolic phospholipase A2 in human pulmonary microvascular endothelial cells. Mice with lung-specific PGI(2)S overexpression exhibited less endothelial apoptosis after chronic smoke exposure. In vitro, iloprost exhibited protective effects on CSE-induced apoptosis. CONCLUSIONS PGI(2) has protective effects in the pulmonary vasculature after acute and chronic cigarette smoke exposure. An imbalance in eicosanoid expression may be important to COPD-associated endothelial dysfunction.
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Affiliation(s)
- S Patrick Nana-Sinkam
- The Ohio State University, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, 201 Davis Heart and Lung Research Institute, 473 West 12th Avenue, Columbus, OH 43210, USA.
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Hortobágyi L, Kis B, Hrabák A, Horváth B, Huszty G, Schweer H, Benyó B, Sándor P, Busija DW, Benyó Z. Adaptation of the hypothalamic blood flow to chronic nitric oxide deficiency is independent of vasodilator prostanoids. Brain Res 2006; 1131:129-37. [PMID: 17161389 PMCID: PMC1820619 DOI: 10.1016/j.brainres.2006.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 10/25/2006] [Accepted: 11/05/2006] [Indexed: 01/21/2023]
Abstract
The aim of our study was to investigate the adaptation of the hypothalamic circulation to chronic nitric oxide (NO) deficiency in rats. Hypothalamic blood flow (HBF) remained unaltered during chronic oral administration of the NO synthase (NOS) inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME, 1 mg/ml drinking water) although acute NOS blockade by intravenous l-NAME injection (50 mg/kg) induced a dramatic HBF decrease. In chronically NOS blocked animals, however, acute l-NAME administration failed to influence the HBF. Reversal of chronic NOS blockade by intravenous l-arginine infusion evoked significant hypothalamic hyperemia suggesting the appearance of a compensatory vasodilator mechanism in the absence of NO. In order to clarify the potential involvement of vasodilator prostanoids in this adaptation, cyclooxygenase (COX) mRNA and protein levels were determined in the hypothalamus, but none of the known isoenzymes (COX-1, COX-2, COX-3) showed upregulation after chronic NOS blockade. Furthermore, levels of vasodilator prostanoid (PGI(2), PGE(2) and PGD(2)) metabolites were also not elevated. Interestingly, however, hypothalamic levels of vasoconstrictor prostanoids (TXA(2) and PGF(2alpha)) decreased after chronic NOS blockade. COX inhibition by indomethacin but not by diclofenac decreased the HBF in control animals. However, neither indomethacin nor diclofenac induced an altered HBF-response after chronic l-NAME treatment. Although urinary excretion of PGI(2) and PGE(2) metabolites markedly increased during chronic NOS blockade, indicating COX activation in the systemic circulation, we conclude that the adaptation of the hypothalamic circulation to the reduction of NO synthesis is independent of vasodilator prostanoids. Reduced release of vasoconstrictor prostanoids, however, may contribute to the normalization of HBF after chronic loss of NO.
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Affiliation(s)
- László Hortobágyi
- Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary
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Abstract
Major advances have been made over the last decade towards the elucidation of the molecular mechanisms involved in the endothelium-dependent regulation of vascular tone and blood flow. While the primary endothelium-derived vasodilator autacoid is nitric oxide, it is clear that epoxyeicosatrienoic acids and other endothelium-derived hyperpolarising factors, as well as endothelin-1 and reactive oxygen species, play a significant role in the regulation of vascular tone and gene expression. This review is intended as an overview of the signalling mechanisms that link haemodynamic stimuli (such as shear stress and cyclic stretch) and endothelial cell perturbation to the activation of enzymes generating vasoactive autacoids.
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Affiliation(s)
- R Busse
- Vascular Signalling Group, Institut für Kardiovaskuläre Physiologie, Klinikum der J.W. Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
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Ohlmann P, Tesse A, Loichot C, Ralay Ranaivo H, Roul G, Philippe C, Watterson DM, Haiech J, Andriantsitohaina R. Deletion of MLCK210 induces subtle changes in vascular reactivity but does not affect cardiac function. Am J Physiol Heart Circ Physiol 2005; 289:H2342-9. [PMID: 16055522 DOI: 10.1152/ajpheart.00511.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myosin light chain kinase (MLCK) plays a key role in the regulation of actomyosin contraction in a large variety of cells. Two isoforms have been described: a short isoform, widely expressed in smooth muscle cells; and a long isoform (MLCK210), mainly localized in the endothelium. This study investigated the consequences on different cardiovascular parameters of MLCK210 gene deletion using MLCK210 knockout mice and of pharmacological inhibition of the kinase using a specific MLCK inhibitor. Deletion of MLCK210 did not affect systolic blood pressure and heart rate or echocardiographic measurements. Electrocardiographic analysis showed neither atrio- nor intraventricular conduction or repolarization defects. Ex vivo responses of aortic rings to vasoconstrictor and vasodilator agonists were not modified in MLCK210 null mice. However, deletion of MLCK210 attenuated shear stress-induced dilation and produced changes in the balance of endothelial-relaxing factors of small mesenteric arteries (SMA). In particular, a reduced flow-mediated NO-dependent dilation was observed. However, it was partially compensated by enhanced indomethacin-sensitive dilation. No significant changes were detected in the endothelium-derived hyperpolarizing component of the vasodilator response. The above effects of MLCK210 gene deletion were confirmed in SMA from wild-type mice by the use of the MLCK enzymatic inhibitor MMZ-10-057. In summary, deletion of MLCK210 was not associated with abnormalities of main in vivo cardiovascular parameters in mice. This study demonstrates a role for MLCK210 in the regulation of flow-dependent dilation in SMA.
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Affiliation(s)
- Patrick Ohlmann
- UMR CNRS 7034, Faculté de Pharmacie, 74, route du Rhin, 67401 Illkirch, France
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Holowatz LA, Thompson CS, Minson CT, Kenney WL. Mechanisms of acetylcholine-mediated vasodilatation in young and aged human skin. J Physiol 2005; 563:965-73. [PMID: 15661816 PMCID: PMC1665610 DOI: 10.1113/jphysiol.2004.080952] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Thermoregulatory cutaneous vasodilatation (VD) is attenuated in aged skin. While acetylcholine (ACh) plays a role in thermally mediated VD, the precise mechanisms through which ACh-mediated VD acts and whether those downstream mechanisms change with ageing are unclear. We tested the hypotheses that both nitric oxide (NO)- and prostanoid-mediated pathways contribute to exogenous ACh-mediated VD, and that both are attenuated with advanced age. Twelve young (Y: 23 +/- 1 years) and 10 older (O: 69 +/- 1 years) subjects underwent infusions of 137.5 mum ACh at four intradermal microdialysis sites: control (C, Ringer solution), NO synthase inhibited (NOS-I, 10 mm l-NAME), cyclooxygenase inhibited (COX-I, 10 mm ketorolac) and NOS-I + COX-I. Red blood cell flux was monitored using laser-Doppler flowmetry, and cutaneous vascular conductance (CVC) was calculated (laser-Doppler flux/mean arterial pressure) and normalized to maximal CVC (%CVC(max)) (28 mm sodium nitroprusside + local heating to 43 degrees C). Baseline %CVC(max) was increased in the O at COX-I sites (COX-I 16 +/- 1, NOS-I + COX-I 16 +/- 2 versus C 10 +/- 1%CVC(max); P < 0.001) but not in the young, suggesting an age-related shift toward COX vasoconstrictors contributing to basal cutaneous vasomotor tone. There was no difference in peak %CVC(max) during ACh infusion between age groups, and the response was unchanged by NOS-I (O: NOS-I 35 +/- 5 versus C 38 +/- 5%CVC(max); P = 0.84) (Y: NOS-I 41 +/- 4 versus C 39 +/- 4%CVC(max); P = 0.67). COX-I and NOS-I + COX-I attenuated the peak CVC response to ACh in both groups (COX-I O: 29 +/- 3, Y: 22 +/- 2%CVC(max) versus C; P < 0.001 both groups; NOS-I + COX-I O: 32 +/- 3 versus Y: 29 +/- 2%CVC(max); versus C; P < 0.001 both groups). ACh mediates cutaneous VD through prostanoid and non-NO-, non-prostanoid-dependent pathways. Further, older subjects have a diminished prostanoid contribution to ACh-mediated VD.
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Affiliation(s)
- Lacy A Holowatz
- The Pennsylvania State University, Noll Laboratory, University Park, PA 16802, USA.
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Bratz IN, Kanagy NL. Nitric oxide synthase-inhibition hypertension is associated with altered endothelial cyclooxygenase function. Am J Physiol Heart Circ Physiol 2004; 287:H2394-401. [PMID: 15319202 DOI: 10.1152/ajpheart.00628.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We reported previously that endothelium-intact superior mesenteric arteries (SMA) from Nω-nitro-l-arginine (l-NNA)-treated hypertensive rats (LHR) contract more to norepinephrine (NE) than SMA from control rats. Others have shown that nitric oxide (NO) synthase (NOS) inhibition increases cyclooxygenase (COX) function and expression. We hypothesized that augmented vascular sensitivity to NE in LHR arteries is caused by decreased NOS-induced dilation and increased COX product-induced constriction. We observed that the EC50 for NE is lower in LHR SMA compared with control SMA (control −6.37 ± 0.04, LHR −7.89 ± 0.09 log mol/l; P < 0.05). Endothelium removal lowered the EC50 (control −7.95 ± 0.11, LHR −8.44 ± 0.13 log mol/l; P < 0.05) and increased maximum tension in control (control 1,036 ± 38 vs. 893 ± 21 mg; P < 0.05) but not LHR (928 ± 30 vs. 1,066 ± 31 mg) SMA. Thus augmented NE sensitivity in LHR SMA depends largely on decreased endothelial dilation. NOS inhibition (l-NNA, 10−4 mol/l) increased maximum tension and EC50 in control arteries but not in LHR arteries. In contrast, COX inhibition decreased maximum tension in control arteries, suggesting that COX products augment contraction. Indomethacin did not affect NE-induced contraction in l-NNA-treated or denuded arteries. In control SMA loaded with the fluorescent NO indicator 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate, indomethacin increased and l-NNA decreased NO release. Therefore, COX products appear to inhibit NO production to augment NE-induced contraction. With chronic NOS inhibition, this modulating influence is greatly diminished. Thus, in NOS-inhibition hypertension, decreased activity of both COX and NOS pathways profoundly disrupts endothelial modulation of contraction.
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Affiliation(s)
- Ian N Bratz
- Vascular Physiology Research Group, MSC 08-4750, Dept. of Cell Biology and Physiology, 1 Univ. of New Mexico Health Sciences Center, Albuquerque, NM 87131-0218, USA
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Li X, Geary GG, Gonzales RJ, Krause DN, Duckles SP. Effect of estrogen on cerebrovascular prostaglandins is amplified in mice with dysfunctional NOS. Am J Physiol Heart Circ Physiol 2004; 287:H588-94. [PMID: 15277199 DOI: 10.1152/ajpheart.01176.2003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic estrogen treatment increases endothelial vasodilator function in cerebral arteries. Endothelial nitric oxide (NO) synthase (eNOS) is a primary target of the hormone, but other endothelial factors may be modulated as well. In light of possible interactions between NO and prostaglandins, we tested the hypothesis that estrogen treatment increases prostanoid-mediated dilation using NOS-deficient female mouse models, i.e., mice treated with a NOS inhibitor [N(G)-nitro-l-arginine methyl ester (l-NAME)] for 21 days or transgenic mice with the eNOS gene disrupted (eNOS(-/-)). All mice were ovariectomized; some in each group were treated chronically with estrogen. Cerebral blood vessels then were isolated for biochemical and functional analyses. In vessels from control mice, estrogen increased protein levels of eNOS but had no significant effect on cyclooxygenase (COX)-1 protein, prostacyclin production, or constriction of pressurized, middle cerebral arteries to indomethacin, a COX inhibitor. In l-NAME-treated mice, however, cerebrovascular COX-1 levels, prostacyclin production, and constriction to indomethacin, as well as eNOS protein, were all greater in estrogen-treated animals. In vessels from eNOS(-/-) mice, estrogen treatment also increased levels of COX-1 protein and constriction to indomethacin, but no effect on prostacyclin production was detected. Thus cerebral blood vessels of control mice did not exhibit effects of estrogen on the prostacyclin pathway. However, when NO production was dysfunctional, the impact of estrogen on a COX-sensitive vasodilator was revealed. Estrogen has multiple endothelial targets; estrogen effects may be modified by interactions among these factors.
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Affiliation(s)
- Xiangduan Li
- Department of Pharmacology, College of Medicine, Univ. of California, Irvine, CA 92697-4625, USA
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Merkus D, Houweling B, Zarbanoui A, Duncker DJ. Interaction between prostanoids and nitric oxide in regulation of systemic, pulmonary, and coronary vascular tone in exercising swine. Am J Physiol Heart Circ Physiol 2003; 286:H1114-23. [PMID: 14563663 DOI: 10.1152/ajpheart.00477.2003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prostacyclin and nitric oxide (NO) are produced by the endothelium in response to physical forces such as shear stress. Consequently, both NO and prostacyclin may increase during exercise and contribute to metabolic vasodilation. Conversely, NO has been hypothesized to inhibit prostacyclin production. We therefore investigated the effect of cyclooxygenase (COX) inhibition on exercise-induced vasodilation of the porcine systemic, pulmonary, and coronary beds before and after inhibition of NO production. Swine were studied at rest and during treadmill exercise at 1-5 km/h, before and after COX inhibition with indomethacin (10 mg/kg iv), and in the absence and presence of NO synthase inhibition with N(omega)-nitro-l-arginine (l-NNA; 20 mg/kg iv). COX inhibition produced systemic vasoconstriction at rest, which waned during exercise. The systemic vasoconstriction by COX inhibition was enhanced after l-NNA, particularly at rest. In the coronary circulation, COX inhibition also resulted in vasoconstriction at rest and during exercise. However, vasoconstriction was not modified by pretreatment with l-NNA. In contrast, COX inhibition had no effect on the pulmonary circulation, either at rest or during exercise. Moreover, a prostanoid influence in the pulmonary circulation could not be detected after l-NNA. In conclusion, endogenous prostanoids contribute importantly to systemic and coronary tone in awake swine at rest but are not mandatory for exercise-induced vasodilation in these beds. Endogenous prostanoids are not mandatory for the regulation of pulmonary resistance vessel tone. Finally, NO blunts the contribution of prostanoids to vascular tone regulation in the systemic but not in the coronary and pulmonary beds.
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Affiliation(s)
- Daphne Merkus
- Experimental Cardiology, Thoraxcenter, Erasmus MC, Univ. Medical Center Rotterdam, Box 1738, 3000 DR Rotterdam, The Netherlands.
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Busse R, Fleming I. Regulation of endothelium-derived vasoactive autacoid production by hemodynamic forces. Trends Pharmacol Sci 2003; 24:24-9. [PMID: 12498727 DOI: 10.1016/s0165-6147(02)00005-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Endothelial cells, which are situated at the interface between blood and the vessel wall, have a crucial role in controlling vascular tone and homeostasis, particularly in determining the expression of pro-atherosclerotic and anti-atherosclerotic genes. Many of these effects are mediated by changes in the generation and release of endothelium-derived autacoids [from the Greek autos (self) and akos (remedy)], which are generally short-lived and locally acting. In vivo, endothelial cells are constantly subjected to mechanical stimulation, which in turn determines the acute production of autacoids and the levels of autacoid-producing enzymes.
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Affiliation(s)
- Rudi Busse
- Institut für Kardiovaskuläre Physiologie, Klinikum der J.W.Goethe.-Universität, Theodor-Stern-Kai 7, D-60590, Frankfurt am Main, Germany
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