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Berna-Erro A, Granados MP, Rosado JA, Redondo PC. Thrombotic Alterations under Perinatal Hypoxic Conditions: HIF and Other Hypoxic Markers. Int J Mol Sci 2023; 24:14541. [PMID: 37833987 PMCID: PMC10572648 DOI: 10.3390/ijms241914541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 10/15/2023] Open
Abstract
Hypoxia is considered to be a stressful physiological condition, which may occur during labor and the later stages of pregnancy as a result of, among other reasons, an aged placenta. Therefore, when gestation or labor is prolonged, low oxygen supply to the tissues may last for minutes, and newborns may present breathing problems and may require resuscitation maneuvers. As a result, poor oxygen supply to tissues and to circulating cells may last for longer periods of time, leading to life-threatening conditions. In contrast to the well-known platelet activation that occurs after reperfusion of the tissues due to an ischemia/reperfusion episode, platelet alterations in response to reduced oxygen exposition following labor have been less frequently investigated. Newborns overcome temporal hypoxic conditions by changing their organ functions or by adaptation of the intracellular molecular pathways. In the present review, we aim to analyze the main platelet modifications that appear at the protein level during hypoxia in order to highlight new platelet markers linked to complications arising from temporal hypoxic conditions during labor. Thus, we demonstrate that hypoxia modifies the expression and activity of hypoxic-response proteins (HRPs), including hypoxia-induced factor (HIF-1), endoplasmic reticulum oxidase 1 (Ero1), and carbonic anhydrase (CIX). Finally, we provide updates on research related to the regulation of platelet function due to HRP activation, as well as the role of HRPs in intracellular Ca2+ homeostasis.
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Affiliation(s)
- Alejandro Berna-Erro
- Department of Physiology (Phycell), University of Extremadura, Avd de la Universidad s/n, 10003 Caceres, Spain; (A.B.-E.); (P.C.R.)
| | | | - Juan Antonio Rosado
- Department of Physiology (Phycell), University of Extremadura, Avd de la Universidad s/n, 10003 Caceres, Spain; (A.B.-E.); (P.C.R.)
| | - Pedro Cosme Redondo
- Department of Physiology (Phycell), University of Extremadura, Avd de la Universidad s/n, 10003 Caceres, Spain; (A.B.-E.); (P.C.R.)
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Chronic obstructive pulmonary disease and atherosclerosis: common mechanisms and novel therapeutics. Clin Sci (Lond) 2022; 136:405-423. [PMID: 35319068 PMCID: PMC8968302 DOI: 10.1042/cs20210835] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/17/2022] [Accepted: 03/07/2022] [Indexed: 12/17/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) and atherosclerosis are chronic irreversible diseases, that share a number of common causative factors including cigarette smoking. Atherosclerosis drastically impairs blood flow and oxygen availability to tissues, leading to life-threatening outcomes including myocardial infarction (MI) and stroke. Patients with COPD are most likely to die as a result of a cardiovascular event, with 30% of all COPD-related deaths being attributed to cardiovascular disease (CVD). Both atherosclerosis and COPD involve significant local (i.e. lung, vasculature) and systemic inflammation and oxidative stress, of which current pharmacological treatments have limited efficacy, hence the urgency for the development of novel life-saving therapeutics. Currently these diseases must be treated individually, with no therapies available that can effectively reduce the likelihood of comorbid CVD other than cessation of cigarette smoking. In this review, the important mechanisms that drive atherosclerosis and CVD in people with COPD are explained and we propose that modulation of both the oxidative stress and the inflammatory burden will provide a novel therapeutic strategy to treat both the pulmonary and systemic manifestations related to these diseases.
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Spears JR. Reperfusion Microvascular Ischemia After Prolonged Coronary Occlusion: Implications And Treatment With Local Supersaturated Oxygen Delivery. HYPOXIA 2019; 7:65-79. [PMID: 31696129 PMCID: PMC6814765 DOI: 10.2147/hp.s217955] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/20/2019] [Indexed: 12/16/2022]
Abstract
Following a prolonged coronary arterial occlusion, heterogeneously scattered, focal regions of low erythrocyte flow are commonly found throughout the reperfused myocardium. Experimental studies have also demonstrated the presence of widespread, focally patchy regions of microvascular ischemia during reperfusion (RMI). However, the potential contribution of RMI to tissue viability and function has received little attention in the absence of practical clinical methods for its detection. In this review, the anatomic/functional basis of RMI is summarized, along with the evidence for its presence in reperfused myocardium. Advances in microcirculation research related to obstructive responses of vascular endothelial cells and blood elements to the effects of hypoxia and low shear stress are discussed, and a potential cycle of intensification of RMI from such responses and progressive loss of functional capillary density is presented. In capillaries with impaired erythrocyte flow, compensatory increases in the delivery of oxygen, because of its low solubility in plasma, are effective only at high partial pressures. As discussed herein, attenuation of the cycle with oxygen at hyperbaric levels in plasma is, very likely, responsible for improved tissue level perfusion noted experimentally. Observed clinical benefits from intracoronary SuperSaturated oxygen (SSO2) delivery, including infarct size reduction, can be attributed to attenuation of RMI with improvement in microvascular blood flow.
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Affiliation(s)
- James Richard Spears
- Cardiovascular Research Laboratory, Department of Medicine, Division of Cardiology, Beaumont Heart & Vascular Center, Dearborn, MI 48124, USA
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Liu D, Pei D, Hu H, Gu G, Cui W. Effects and Mechanisms of Vitamin C Post-Conditioning on Platelet Activation after Hypoxia/Reoxygenation. Transfus Med Hemother 2019; 47:110-118. [PMID: 32355470 DOI: 10.1159/000500492] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 04/17/2019] [Indexed: 12/11/2022] Open
Abstract
Background Platelet activation occurs upon ischemia/reperfusion and is related to the generation of reactive oxygen species (ROS) during this process. Vitamin C (VC) is a powerful antioxidant. VC scavenges ROS, reduces platelet activation, and attenuates reperfusion injury. However, the effects of VC on platelets undergoing hypoxia/reoxygenation (H/R) remain unclear. Objectives Herein, we evaluated the effects of VC on platelets in vitro following H/R and the related mechanisms. Method Fresh platelets were collected from 67 volunteers at the Blood Center of Hebei Province. Platelets were diluted with saline to a concentration of 2.00 × 10<sup>11</sup>/L. Aggregation and the curve slope were evaluated within 4 h with a whole-blood impedance analyzer. To determine the optimal experimental time, platelets were treated with hypoxia or reoxygenation for different times, and impedance aggregometry was carried out by measuring changes in electrical impedance induced by arachidonic acid (0.5 mM) and adenosine diphosphate (10 µM), thereby establishing the H/R model. Three antioxidants (VC, melatonin, and probucol) were used to treat platelets after H/R, and impedance aggregometry was used to determine their effects on platelet aggregation. The influence of VC on apoptosis-related indicators was detected. ROS and the mitochondrial membrane potential were observed by inverted fluorescence microscopy and flow cytometry, respectively. Related protein levels were detected by Western blotting. Results ROS scavengers inhibited platelet activation and aggregation in a concentration-dependent manner. VC post-conditioning scavenged ROS, downregulated cytochrome C, Bax, and caspase-9 proteins, and upregulated Bcl-2 protein. These effects collectively blocked platelet apoptosis and inhibited platelet aggregation. Conclusions VC inhibited platelet aggregation by blocking apoptosis. Thus, VC may have applications in the treatment of platelet-related diseases.
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Affiliation(s)
- Demin Liu
- Department of Cardiology, Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Dongguo Pei
- Department of Cardiology, Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Haijuan Hu
- Department of Cardiology, Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Guoqiang Gu
- Department of Cardiology, Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Wei Cui
- Department of Cardiology, Second Hospital of Hebei Medical University, Shijiazhuang, China
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5
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Platelets redox balance assessment: Current evidence and methodological considerations. Vascul Pharmacol 2017; 93-95:6-13. [DOI: 10.1016/j.vph.2017.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/10/2017] [Accepted: 06/28/2017] [Indexed: 01/22/2023]
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Abstract
The role of platelets as inflammatory cells is now well established. Given the peculiar characteristics of the lung circulation, with a broad capillary bed, platelets are especially involved with the physiology of the lungs and play a key role in a number of inflammatory lung disorders. The platelet precursors, megakaryocytes, are detected in the lung microcirculation; moreover platelets with their endothelium-protective and vascular reparative activities contribute to the lung capillary blood barrier integrity. Given the function of the lungs as first wall against pathogen invasion, platelets participate in immune defence of the normal lung. On the other hand, platelets may turn into effectors of the inflammatory reaction of the lungs to allergens, to infectious agents, to chemical agents and may contribute strongly to the perpetuation of chronic inflammatory reactions, largely by their ability to interact with other inflammatory cells and the endothelium. In this chapter we provide an overview of the role of platelets in several inflammatory lung disorders discussing the pathophysiologic bases of platelet involvement in these conditions and the experimental and clinical evidence for a role of platelets in lung diseases.
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Malerba M, Clini E, Malagola M, Avanzi GC. Platelet activation as a novel mechanism of atherothrombotic risk in chronic obstructive pulmonary disease. Expert Rev Hematol 2014; 6:475-83. [PMID: 23991933 DOI: 10.1586/17474086.2013.814835] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) is characterized by pulmonary and systemic inflammation. In particular, the clinical course of this disease typically leads to periodic exacerbation involving inflammatory response and both respiratory and cardiovascular symptoms. Even though the exact mechanisms underlying the pathogenesis of COPD and its chronic and acute inflammation have not yet been fully understood, many studies have been highlighting the role of the endothelium, platelets (PTL) and other circulating blood cells. PLT are crucial for hemostasis and, once activated by a number of different factors, will mediate endothelium adhesion, and the rolling and activation of other circulating cells, such as neutrophils, which become a cause of tissue damage during the inflammatory process. The aim of this review is to highlight the onset of activation, thrombus formation and inflammatory amplification with particular regard to the COPD patients and the course of their acute exacerbations.
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Affiliation(s)
- Mario Malerba
- Dipartimento di Medicina Interna--Az. Spedali Civili di Brescia e Università di Brescia.
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Clini EM, Beghé B, Fabbri LM. Chronic obstructive pulmonary disease is just one component of the complex multimorbidities in patients with COPD. Am J Respir Crit Care Med 2013; 187:668-71. [PMID: 23540872 DOI: 10.1164/rccm.201302-0230ed] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Clinical value of mean platelet volume for impaired cardiopulmonary function in very old male patients with chronic obstructive pulmonary disease. Arch Gerontol Geriatr 2012; 54:e109-12. [DOI: 10.1016/j.archger.2011.09.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 09/22/2011] [Accepted: 09/25/2011] [Indexed: 10/16/2022]
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Fimognari FL, Scarlata S, Conte ME, Incalzi RA. Mechanisms of atherothrombosis in chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis 2008; 3:89-96. [PMID: 18488431 PMCID: PMC2528208 DOI: 10.2147/copd.s1401] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Patients affected by chronic obstructive pulmonary disease (COPD) have an increased risk of atherothrombotic acute events, independent of smoking and other cardiovascular risk factors. As a consequence, myocardial ischemia is a relevant cause of death in these patients. We reviewed studies concerning the potential mechanisms of atherothrombosis in COPD. Bronchial inflammation spreads to the systemic circulation and is known to play a key role in plaque formation and rupture. In fact, C-reactive protein blood levels increase in COPD and provide independent prognostic information. Systemic inflammation is the first cause of the hypercoagulable state commonly observed in COPD. Furthermore, hypoxia is supposed to activate platelets, thus accounting for the increased urinary excretion of platelet-derived thromboxane in COPD. The potential metabolic risk in COPD is still debated, in that recent studies do not support an association between COPD and diabetes mellitus. Finally, oxidative stress contributes to the pathogenesis of COPD and may promote oxidation of low-density-lipoproteins with foam cells formation. Retrospective observations suggest that inhaled corticosteroids may reduce atherothrombotic mortality by attenuating systemic inflammation, but this benefit needs confirmation in ongoing randomized controlled trials. Physicians approaching COPD patients should always be aware of the systemic vascular implications of this disease.
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Affiliation(s)
- Filippo Luca Fimognari
- Health Centre for Elderly, Chair of Geriatrics, University Campus Bio Medico, Rome, Italy
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11
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Cheung PY, Stevens JP, Haase E, Stang L, Bigam DL, Etches W, Radomski MW. Platelet dysfunction in asphyxiated newborn piglets resuscitated with 21% and 100% oxygen. Pediatr Res 2006; 59:636-40. [PMID: 16627873 DOI: 10.1203/01.pdr.0000214894.18097.c4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Hemostatic disturbances are common in asphyxiated newborns after resuscitation. We compared platelet function in hypoxic newborn piglets reoxygenated with 21% or 100% oxygen. Piglets (1-3 d, 1.5-2.1 kg) were anesthetized and acutely instrumented for hemodynamic monitoring. After stabilization, normocapnic hypoxia was induced with an inspired oxygen concentration of 10-15% for 2 h. Piglets were then resuscitated for 1 h with 21% or 100% oxygen, followed by 3 h with 21% oxygen. Platelet counts and collagen (2, 5, and 10 microg/mL)-stimulated whole blood aggregation were studied before hypoxia and at 4 h of post-hypoxia/reoxygenation. Platelet function was studied using transmission electron microscopy and by measuring plasma thromboxane B2 (TxB2) and matrix metalloproteinase (MMP)-2 and -9 levels. Control piglets were sham-operated without hypoxia/reoxygenation. The hypoxemic (PaO2 33 mm Hg) piglets developed hypotension with metabolic acidosis (pH 7.02-7.05). Upon reoxygenation, piglets recovered and blood gases gradually normalized. At 4 h reoxygenation, platelet aggregation ex vivo was impaired as evidenced by a rightward-downward shifting of the concentration-response curves. Electron microscopy showed features of platelet activation. Plasma MMP-9 but not MMP-2 activity significantly increased. Resuscitation with 100% but not 21% oxygen increased plasma TxB2 levels. Platelet counts decreased after hypoxia/reoxygenation but were not different between groups during the experiment. Resuscitation of hypoxic newborn piglets caused platelet activation with significant deterioration of platelet aggregation ex vivo and increased plasma MMP-9 levels. High oxygen concentrations may aggravate the activation of prostaglandin-thromboxane mechanistic pathway.
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Affiliation(s)
- Po-Yin Cheung
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada, T6G 2S2.
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Miñambres E, González AM, Mayorga M, Zurbano F, Díaz-Regañón G. Nonbacterial thrombotic endocarditis after lung transplantation. Heart Lung 2005; 34:433-6. [PMID: 16324964 DOI: 10.1016/j.hrtlng.2005.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 04/26/2004] [Accepted: 03/04/2005] [Indexed: 11/18/2022]
Abstract
Bacteria-free verrucae has been recognized as a condition associated with several clinical conditions such as bone marrow transplantation, malignant tumors, autoimmune disorders, and acquired immunodeficiency syndrome, but it has not been reported in relation to lung transplantation. We report the case of a patient who underwent bilateral lung transplant and died 3 days later. Histologic examination revealed, among other lesions, the presence of nonbacterial thrombotic endocarditis in the right atrium and mitral and tricuspid valves that was not present in the preoperative echocardiographic studies. Even with transesophageal echocardiography, a reliable detection of vegetations may not be possible. Hypoxigenic pulmonary states developed in the course of lung transplant could be the factor that triggers the interaction between the coagulation system, platelets, and endothelial cells that induce the formation of bacteria-free verrucae.
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Affiliation(s)
- Eduardo Miñambres
- Services of Intensive Care, University Hospital Marqués de Valdecilla, 39008 Santander, Spain
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Bozzo J, Hernández MR, Galán AM, Heras M, Ordinas A, Escolar G. Impaired antiplatelet effects of aspirin associated with hypoxia and ATP release from erythrocytes. Studies in a system with flowing human blood. Eur J Clin Invest 1999; 29:438-44. [PMID: 10354201 DOI: 10.1046/j.1365-2362.1999.00483.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND We have explored how hypoxic conditions may affect the antiplatelet effects of aspirin. MATERIALS AND METHODS For this purpose, a perfusion system containing a damaged vessel segment was modified in order to induce hypoxia (low Po2) in flowing blood. Blood samples were incubated with 50 mumol L-1 aspirin and divided into two aliquots, one being perfused under standard conditions (normoxic) and the other under hypoxic conditions. The interaction of platelets with the subendothelium was morphometrically evaluated. RESULTS In studies with untreated blood under normoxic conditions, platelet interaction with the subendothelium was 0.3 +/- 0.1% of contact, 5.3 +/- 1.6% of adhesion, 24.3 +/- 3.3% of thrombus and 29.9 +/- 2.7% of total covered surface. Aspirin-treated blood perfused under normoxic conditions showed a marked decrease in thrombus with a concomitant increase in both platelet adhesion and covered surface percentages. However, when aspirin-treated blood was perfused under hypoxic conditions, platelet interaction was not significantly different from that observed in untreated blood. Hypoxia induced a 10-fold increase in ATP release from erythrocytes in the perfusates. If apyrase was added to the perfusates, ATP release was prevented and aspirin effects were evident again. CONCLUSION Our results suggest that, under hypoxic conditions, the presence of aspirin would not help to inhibit further platelet activation.
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Affiliation(s)
- J Bozzo
- Hospital Clínic, Servei d'Hemoteràpia i Hemostàsia, Barcelona, Spain
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Davì G, Basili S, Vieri M, Cipollone F, Santarone S, Alessandri C, Gazzaniga P, Cordova C, Violi F. Enhanced thromboxane biosynthesis in patients with chronic obstructive pulmonary disease. The Chronic Obstructive Bronchitis and Haemostasis Study Group. Am J Respir Crit Care Med 1997; 156:1794-9. [PMID: 9412557 DOI: 10.1164/ajrccm.156.6.9706026] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Thrombotic complications of pulmonary circulation occur in patients with chronic obstructive pulmonary disease (COPD). In the present study, we sought to evaluate in vivo platelet activation through the measurement of 11/dehydro-thromboxane (Tx) B2 TxA2 major metabolite in the urine, in 29 patients with COPD, compared with 29 sex- and age-matched healthy subjects. The urinary excretion of 11-dehydro-TxB2 was significantly higher in patients with COPD than in control subjects: median (range), 753 (277-4,409) and 275 (129-612) pg/mg creatinine, respectively; p < 0.0001). Moreover, 11-dehydro-TxB2 excretion was inversely related with arterial oxygen tension (rho = -0.46; p = 0.0145). In five of the 29 patients a short-term therapeutic course with oxygen supplementation induced a significant decrease of urinary 11-dehydro-TxB2 excretion: median range, 941 (452-2,640) to 445 (166-1,560) pg/mg creatinine. Moreover, selective inhibition of platelet cyclooxygenase activity by low-dose aspirin was associated with more than 90% inhibition of thromboxane metabolite excretion, demonstrating its being of platelet origin. Plasma levels of prothrombin fragment F1 + 2 were higher in patients than in control subjects (2.6 +/- 1.5 versus 0.9 +/- 0.4 nM, p = 0.0001). No relation between 11-dehydro-TxB2 excretion and plasma F1 + 2 levels was found. We conclude that platelet TxA2 biosynthesis is enhanced in patients with COPD and may be influenced by arterial oxygen tension changes.
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Affiliation(s)
- G Davì
- Dipartimento di Medicina Sperimentale e Patologia, Università di Roma La Sapienza, Italy
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Abstract
Nitric oxide (NO) is a mediator that modulates vessel wall tone and hemostatic-thrombotic balance. Platelet function is regulated by NO generated from platelets, endothelial cells and leukocytes. Nitric oxide has been shown to inhibit platelet adhesion, aggregation, and stimulate disaggregation of preformed platelet aggregates. Many of the effects of NO are mediated by its stimulation of guanylate cyclase and the formation of cyclic GMP and its subsequent transduction mechanism. In vivo, NO is likely to interact with prostacyclin, metabolites of ecto-nucleotidase, and lipoxygenase to modulate platelet function in a synergistic manner. An imbalance of NO production (deficiency or overproduction) has been implicated in the pathogenesis of various vascular disorders including thrombosis, atherosclerosis, septicemia, and ischemia-reperfusion injury. It is likely that some of detrimental effects of NO are mediated through its reaction with superoxide anion to form the potent oxidant, peroxynitrite. Nitric oxide gas and NO donors are used for the pharmacological treatment of various vascular disorders. Because inhaled NO has been documented to improve systemic oxygenation and reduce the need for extracorporeal membrane oxygenation, it has been widely used in neonates with severe hypoxemia. An inhibition of platelet function, resulting in a prolonged bleeding time, has been shown in adults receiving inhaled NO. Because bleeding complications may occur in high-risk infants, it is important to evaluate the effect of inhaled NO on platelet function and its correlation with clinical consequences such as intracranial hemorrhage. For these reasons, hemostasis should be carefully monitored during the administration of inhaled NO to critically ill neonates.
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Affiliation(s)
- P Y Cheung
- Department of Pharmacology, Pediatrics, and Obstetrics and Gynecology, University of Alberta, Edmonton, Canada
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Rautanen M, Gullichsen E, Riutta A, Kuttila K, Mucha I, Nelimarkka O, Niinikoski J. Experimental fat embolism induces urine 2,3-dinor-6-ketoprostaglandin F1alpha and 11-dehydrothromboxane B2 excretion in pigs. Crit Care Med 1997; 25:1215-21. [PMID: 9233750 DOI: 10.1097/00003246-199707000-00025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To evaluate the in vivo production of prostacyclin and thromboxane A2 during the initial phase of experimental fat embolism as assessed, respectively, by determinations of urine 2,3-dinor-6-ketoprostaglandin F1alpha and 11-dehydrothromboxane B2 excretion. DESIGN Randomized, controlled trial. SETTING Animal laboratory. SUBJECTS Twenty seven domestic pigs, weighing 24 to 31 kg. INTERVENTIONS All pigs were anesthetized and mechanically ventilated during the experiment. Eighteen pigs were subjected to an intracaval infusion of 10% allogeneic bone marrow suspension at a dose of 100 mg/kg over 5 mins. Nine pigs received only bone marrow suspension (fat embolism group). Nine pigs were given an intravenous bolus of aspirin (300 mg) 1 hr before the bone marrow suspension infusion. After the induction of fat embolism, intravenous aspirin was administered at a dose of 150 mg/hr for 2 hrs (aspirin-treated group). Nine pigs were infused with saline (control group). MEASUREMENTS AND MAIN RESULTS In the fat embolism group, cardiac index decreased within 30 mins, while mean arterial pressure remained unchanged. Central venous pressure and pulmonary artery occlusion pressure remained relatively stable over time in the animals with fat embolism. Mean pulmonary arterial pressure and pulmonary vascular resistance increased immediately after the bone marrow suspension infusion from 23 +/- 0.8 (SEM) to 34 +/- 1.3 mm Hg and from 305 +/- 28 to 585 +/- 45 dyne x sec/cm5, respectively; these variables remained increased throughout the study period. Simultaneously, pulmonary shunt in the fat embolism group increased persistently from the baseline of 12.3 +/- 2.8%, and reached its maximum of 26.1 +/- 4.8% at the end of the experiment. Instant and gradual decreases in PaO2 (from 95 +/- 4 to 67 +/- 5 torr [12.6 +/- 0.5 to 8.9 +/- 0.7 kPa]), hemoglobin oxygen saturation (from 97.2 +/- 0.4 to 91.8 +/- 1.8%), and oxygen delivery (from 16.3 +/- 1.0 to 12.6 +/- 0.4 mL/min/kg) were observed in the fat embolism group. In the bone marrow suspension-infused animals, urine 2,3-dinor-6-ketoprostaglandin F1alpha excretion increased transiently from 451 +/- 63 up to 1466 +/- 499 pg/micromol creatinine, while urine 11-dehydrothromboxane B2 excretion increased transiently from 385 +/- 36 up to 2307 +/- 685 pg/micromol creatinine. In the aspirin-treated animals, urinary excretion of these prostanoid metabolites was reduced by 81% and 88%, respectively. The changes in mean pulmonary arterial pressure and PaO2 were ameliorated, and the alterations in pulmonary shunt and SaO2 were abolished in the animals with aspirin treatment. CONCLUSIONS Pulmonary hypertension, increased pulmonary vascular tone, and increased pulmonary shunt are hallmarks of the present fat embolism model. These hemodynamic responses may, at least partly, be related to the changed balance between prostacyclin and thromboxane A2 production.
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Affiliation(s)
- M Rautanen
- Department of Surgery, University of Turku, Finland
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Daley JT, Brown ML, Watkins T, Traish AM, Huang YH, Moreland RB, De Tejada IS. Prostanoid production in rabbit corpus cavernosum: I. regulation by oxygen tension. J Urol 1996. [PMID: 8632615 DOI: 10.1016/s0022-5347(01)66311-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE To investigate the effects of oxygen tension on prostanoid synthesis in rabbit penile corpus cavernosum tissue (RCC) in organ culture. MATERIALS AND METHODS Strips of rabbit corpus cavernosum were incubated in organ culture media under varying oxygen conditions (0%, 12% and 21% oxygen), in the presence or absence of acetylcholine and arachidonate stimulation. Prostanoids were measured in collected media by radioimmunoassay. Prostaglandin H synthase (PGHS) protein levels and mRNA PGHS expression were measured under both 0% and 21% oxygen conditions. RESULTS Basal and acetylcholine-stimulated PGI2 release was progressively diminished as a function of diminishing oxygen tension (pO2 from approximately 165 to 25 mm.Hg). The basal and stimulated production of other prostanoids, thromboxane A2, PGF2alpha, and PGE2, was also significantly inhibited under 0% oxygen (approximately 25 mm.Hg) conditions. However, incubation under 0% oxygen did not alter PGHS protein levels nor mRNA PGHS expression. Cavernosal strips incubated under 0% oxygen but supplemented with exogenous arachidonate (10 microM.) maintained significantly lower PGI2 production than tissues exposed to 21% oxygen (approximately 165 mm.Hg). CONCLUSIONS These data demonstrate that oxygen tension regulates prostaglandin production in corporal tissue. The reduction in prostanoid production during hypoxia can be attributed to inhibition of PGHS activity rather than the expression of the enzyme. In view of the role of PGI2 as an inhibitor of platelet aggregation and white cell-endothelial adhesion, our findings may provide mechanistic insight into the alteration in corporal blood homeostasis ischemic-hypoxic priapism.
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Affiliation(s)
- J T Daley
- Department of Urology, Boston University School of Medicine, Massachusetts, USA
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