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Beñaldo FA, Araya-Quijada C, Ebensperger G, Herrera EA, Reyes RV, Moraga FA, Riquelme A, Gónzalez-Candia A, Castillo-Galán S, Valenzuela GJ, Serón-Ferré M, Llanos AJ. Cinaciguat (BAY-582667) Modifies Cardiopulmonary and Systemic Circulation in Chronically Hypoxic and Pulmonary Hypertensive Neonatal Lambs in the Alto Andino. Front Physiol 2022; 13:864010. [PMID: 35733986 PMCID: PMC9207417 DOI: 10.3389/fphys.2022.864010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/13/2022] [Indexed: 11/13/2022] Open
Abstract
Neonatal pulmonary hypertension (NPHT) is produced by sustained pulmonary vasoconstriction and increased vascular remodeling. Soluble guanylyl cyclase (sGC) participates in signaling pathways that induce vascular vasodilation and reduce vascular remodeling. However, when sGC is oxidized and/or loses its heme group, it does not respond to nitric oxide (NO), losing its vasodilating effects. sGC protein expression and function is reduced in hypertensive neonatal lambs. Currently, NPHT is treated with NO inhalation therapy; however, new treatments are needed for improved outcomes. We used Cinaciguat (BAY-582667), which activates oxidized and/or without heme group sGC in pulmonary hypertensive lambs studied at 3,600 m. Our study included 6 Cinaciguat-treated (35 ug kg−1 day−1x 7 days) and 6 Control neonates. We measured acute and chronic basal cardiovascular variables in pulmonary and systemic circulation, cardiovascular variables during a superimposed episode of acute hypoxia, remodeling of pulmonary arteries and changes in the right ventricle weight, vasoactive functions in small pulmonary arteries, and expression of NO-sGC-cGMP signaling pathway proteins involved in vasodilation. We observed a decrease in pulmonary arterial pressure and vascular resistance during the acute treatment. In contrast, the pulmonary pressure did not change in the chronic study due to increased cardiac output, resulting in lower pulmonary vascular resistance in the last 2 days of chronic study. The latter may have had a role in decreasing right ventricular hypertrophy, although the direct effect of Cinaciguat on the heart should also be considered. During acute hypoxia, the pulmonary vascular resistance remained low compared to the Control lambs. We observed a higher lung artery density, accompanied by reduced smooth muscle and adventitia layers in the pulmonary arteries. Additionally, vasodilator function was increased, and vasoconstrictor function was decreased, with modifications in the expression of proteins linked to pulmonary vasodilation, consistent with low pulmonary vascular resistance. In summary, Cinaciguat, an activator of sGC, induces cardiopulmonary modifications in chronically hypoxic and pulmonary hypertensive newborn lambs. Therefore, Cinaciguat is a potential therapeutic tool for reducing pulmonary vascular remodeling and/or right ventricular hypertrophy in pulmonary arterial hypertension syndrome.
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Affiliation(s)
- Felipe A. Beñaldo
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Claudio Araya-Quijada
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Germán Ebensperger
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Emilio A. Herrera
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - Roberto V. Reyes
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Fernando A. Moraga
- Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
| | - Alexander Riquelme
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | | | - Sebastián Castillo-Galán
- Laboratory of Nano-Regenerative Medicine, Research and Innovation Center Biomedical (CIIB), Faculty of Medicine, University of Los Andes, Santiago, Chile
| | - Guillermo J. Valenzuela
- Department of Women’s Health, Arrowhead Regional Medical Center, San Bernardino, CA, United States
| | - María Serón-Ferré
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Aníbal J. Llanos
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
- *Correspondence: Aníbal J. Llanos,
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Coburn RF. Coronary and cerebral metabolism-blood flow coupling and pulmonary alveolar ventilation-blood flow coupling may be disabled during acute carbon monoxide poisoning. J Appl Physiol (1985) 2020; 129:1039-1050. [PMID: 32853110 DOI: 10.1152/japplphysiol.00172.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Current evidence indicates that the toxicity of carbon monoxide (CO) poisoning results from increases in reactive oxygen species (ROS) generation plus tissue hypoxia resulting from decreases in capillary Po2 evoked by effects of increases in blood [carboxyhemoglobin] on the oxyhemoglobin dissociation curve. There has not been consideration of how increases in Pco could influence metabolism-blood flow coupling, a physiological mechanism that regulates the uniformity of tissue Po2, and alveolar ventilation-blood flow coupling, a mechanism that increases the efficiency of pulmonary O2 uptake. Using published data, I consider hypotheses that these coupling mechanisms, triggered by O2 and CO sensors located in arterial and arteriolar vessels in the coronary and cerebral circulations and in lung intralobar arteries, are disrupted during acute CO poisoning. These hypotheses are supported by calculations that show that the Pco in these vessels can reach levels during CO poisoning that would exert effects on signal transduction molecules involved in these coupling mechanisms.NEW & NOTEWORTHY This article introduces and supports a postulate that the tissue hypoxia component of carbon monoxide poisoning results in part from impairment of physiological adaptation mechanisms whereby tissues can match regional blood flow to O2 uptake, and the lung can match regional blood flow to alveolar ventilation.
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Affiliation(s)
- Ronald F Coburn
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Reyes RV, Herrera EA, Ebensperger G, Sanhueza EM, Giussani DA, Llanos AJ. Perinatal cardiopulmonary adaptation to the thin air of the Alto Andino by a native Altiplano dweller, the llama. J Appl Physiol (1985) 2020; 129:152-161. [PMID: 32584666 DOI: 10.1152/japplphysiol.00800.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Most mammals have a poor tolerance to hypoxia, and prolonged O2 restriction can lead to organ injury, particularly during fetal and early postnatal life. Nevertheless, the llama (Lama Glama) has evolved efficient mechanisms to adapt to acute and chronic perinatal hypoxia. One striking adaptation is the marked peripheral vasoconstriction measured in the llama fetus in response to acute hypoxia, which allows efficient redistribution of cardiac output toward the fetal heart and adrenal glands. This strong peripheral vasoconstrictor tone is triggered by a carotid body reflex and critically depends on α-adrenergic signaling. A second adaptation is the ability of the llama fetus to protect its brain against hypoxic damage. During hypoxia, in the llama fetus there is no significant increase in brain blood flow. Instead, there is a fall in brain O2 consumption and temperature, together with a decrease of Na+-K+-ATPase activity and Na+ channels expression, protecting against seizures and neuronal death. Finally, the newborn llama does not develop pulmonary hypertension in response to chronic hypoxia. In addition to maintaining basal pulmonary arterial pressure at normal levels the pulmonary arterial pressor response to acute hypoxia is lower in highland than in lowland llamas. The protection against hypoxic pulmonary arterial hypertension and pulmonary contractile hyperreactivity is partly due to increased hemoxygenase-carbon monoxide signaling and decreased Ca2+ sensitization in the newborn llama pulmonary vasculature. These three striking physiological adaptations of the llama allow this species to live and thrive under the chronic influence of the hypobaric hypoxia of life at high altitude.
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Affiliation(s)
- R V Reyes
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - E A Herrera
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - G Ebensperger
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - E M Sanhueza
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - D A Giussani
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - A J Llanos
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
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Deng X, Yasuda H, Sasaki T, Yamaya M. Low-Dose Carbon Monoxide Inhibits Rhinovirus Replication in Human Alveolar and Airway Epithelial Cells. TOHOKU J EXP MED 2019; 247:215-222. [PMID: 30971638 DOI: 10.1620/tjem.247.215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Carbon monoxide (CO) and nitric oxide (NO) exhibit physiological properties that include the activation of guanylate cyclase. NO inhibits replication of rhinovirus (RV), a major cause of the common cold and exacerbation of bronchial asthma and chronic obstructive pulmonary disease. However, the anti-rhinoviral effects of CO remain unclear. This study investigated whether the exogenous application of low-dose CO could inhibit RV replication in human alveolar and airway epithelial cells. A549 human lung carcinoma cells with alveolar epithelial features and primary cultures of human tracheal epithelial (HTE) cells were pretreated with CO (100 ppm) and infected with a major group RV, type 14 RV (RV14). CO exposure reduced RV14 titers in the supernatants and RV RNA levels in A549 and HTE cells. The treatment with a guanylate cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, reversed the inhibitory effects of CO exposure on RV14 replication in A549 cells. Pretreatment of A549 cells with 8-Br-cGMP, a cell-permeable cGMP analog, caused the decrease in RV14 replication, while CO exposure increased cGMP production. CO exposure also increased the expression levels of interferon (IFN)-γ mRNA and protein. In contrast, pretreatment with CO did not increase DNA fragmentation and did not reduce the expression of intercellular adhesion molecule-1, the RV14 receptor, or the number of acidic endosomes, through which RV RNA enters the cytoplasm. These findings suggest that low-dose CO may decrease RV14 replication in alveolar and airway epithelial cells. IFN-γ production, which is induced by CO exposure via guanylate cyclase activation-mediated cGMP production, may be involved in RV14 replication inhibition.
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Affiliation(s)
- Xue Deng
- Department of Advanced Preventive Medicine for Infectious Disease, Tohoku University Graduate School of Medicine
| | | | | | - Mutsuo Yamaya
- Department of Advanced Preventive Medicine for Infectious Disease, Tohoku University Graduate School of Medicine
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Otterbein LE, Foresti R, Motterlini R. Heme Oxygenase-1 and Carbon Monoxide in the Heart: The Balancing Act Between Danger Signaling and Pro-Survival. Circ Res 2017; 118:1940-1959. [PMID: 27283533 DOI: 10.1161/circresaha.116.306588] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/02/2016] [Indexed: 12/22/2022]
Abstract
Understanding the processes governing the ability of the heart to repair and regenerate after injury is crucial for developing translational medical solutions. New avenues of exploration include cardiac cell therapy and cellular reprogramming targeting cell death and regeneration. An attractive possibility is the exploitation of cytoprotective genes that exist solely for self-preservation processes and serve to promote and support cell survival. Although the antioxidant and heat-shock proteins are included in this category, one enzyme that has received a great deal of attention as a master protective sentinel is heme oxygenase-1 (HO-1), the rate-limiting step in the catabolism of heme into the bioactive signaling molecules carbon monoxide, biliverdin, and iron. The remarkable cardioprotective effects ascribed to heme oxygenase-1 are best evidenced by its ability to regulate inflammatory processes, cellular signaling, and mitochondrial function ultimately mitigating myocardial tissue injury and the progression of vascular-proliferative disease. We discuss here new insights into the role of heme oxygenase-1 and heme on cardiovascular health, and importantly, how they might be leveraged to promote heart repair after injury.
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Affiliation(s)
- Leo E Otterbein
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215
| | - Roberta Foresti
- Inserm, U955, Equipe 12, Créteil, 94000, France.,University Paris Est, Faculty of Medicine, Créteil, 94000, France
| | - Roberto Motterlini
- Inserm, U955, Equipe 12, Créteil, 94000, France.,University Paris Est, Faculty of Medicine, Créteil, 94000, France
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Duke JW, Davis JT, Ryan BJ, Elliott JE, Beasley KM, Hawn JA, Byrnes WC, Lovering AT. Decreased arterial PO2, not O2 content, increases blood flow through intrapulmonary arteriovenous anastomoses at rest. J Physiol 2016; 594:4981-96. [PMID: 27062157 DOI: 10.1113/jp272211] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/23/2016] [Indexed: 12/25/2022] Open
Abstract
KEY POINTS The mechanism(s) that regulate hypoxia-induced blood flow through intrapulmonary arteriovenous anastomoses (QIPAVA ) are currently unknown. Our previous work has demonstrated that the mechanism of hypoxia-induced QIPAVA is not simply increased cardiac output, pulmonary artery systolic pressure or sympathetic nervous system activity and, instead, it may be a result of hypoxaemia directly. To determine whether it is reduced arterial PO2 (PaO2) or O2 content (CaO2) that causes hypoxia-induced QIPAVA , individuals were instructed to breathe room air and three levels of hypoxic gas at rest before (control) and after CaO2 was reduced by 10% by lowering the haemoglobin concentration (isovolaemic haemodilution; Low [Hb]). QIPAVA , assessed by transthoracic saline contrast echocardiography, significantly increased as PaO2 decreased and, despite reduced CaO2 (via isovolaemic haemodilution), was similar at iso-PaO2. These data suggest that, with alveolar hypoxia, low PaO2 causes the hypoxia-induced increase in QIPAVA , although where and how this is detected remains unknown. ABSTRACT Alveolar hypoxia causes increased blood flow through intrapulmonary arteriovenous anastomoses (QIPAVA ) in healthy humans at rest. However, it is unknown whether the stimulus regulating hypoxia-induced QIPAVA is decreased arterial PO2 (PaO2) or O2 content (CaO2). CaO2 is known to regulate blood flow in the systemic circulation and it is suggested that IPAVA may be regulated similar to the systemic vasculature. Thus, we hypothesized that reduced CaO2 would be the stimulus for hypoxia-induced QIPAVA . Blood volume (BV) was measured using the optimized carbon monoxide rebreathing method in 10 individuals. Less than 5 days later, subjects breathed room air, as well as 18%, 14% and 12.5% O2 , for 30 min each, in a randomized order, before (CON) and after isovolaemic haemodilution (10% of BV withdrawn and replaced with an equal volume of 5% human serum albumin-saline mixture) to reduce [Hb] (Low [Hb]). PaO2 was measured at the end of each condition and QIPAVA was assessed using transthoracic saline contrast echocardiography. [Hb] was reduced from 14.2 ± 0.8 to 12.8 ± 0.7 g dl(-1) (10 ± 2% reduction) from CON to Low [Hb] conditions. PaO2 was no different between CON and Low [Hb], although CaO2 was 10.4%, 9.2% and 9.8% lower at 18%, 14% and 12.5% O2 , respectively. QIPAVA significantly increased as PaO2 decreased and, despite reduced CaO2, was similar at iso-PaO2. These data suggest that, with alveolar hypoxia, low PaO2 causes the hypoxia-induced increase in QIPAVA . Whether the low PO2 is detected at the carotid body, airway and/or the vasculature remains unknown.
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Affiliation(s)
- Joseph W Duke
- Ohio University, Division of Exercise Physiology, Athens, OH, USA
| | - James T Davis
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
| | - Benjamin J Ryan
- University of Colorado at Boulder, Department of Integrative Physiology, Boulder, CO, USA
| | | | - Kara M Beasley
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
| | - Jerold A Hawn
- Oregon Heart and Vascular Institute, Springfield, OR, USA
| | - William C Byrnes
- University of Colorado at Boulder, Department of Integrative Physiology, Boulder, CO, USA
| | - Andrew T Lovering
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
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Papamatheakis DG, Blood AB, Kim JH, Wilson SM. Antenatal hypoxia and pulmonary vascular function and remodeling. Curr Vasc Pharmacol 2014; 11:616-40. [PMID: 24063380 DOI: 10.2174/1570161111311050006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 06/25/2012] [Accepted: 07/12/2012] [Indexed: 01/02/2023]
Abstract
This review provides evidence that antenatal hypoxia, which represents a significant and worldwide problem, causes prenatal programming of the lung. A general overview of lung development is provided along with some background regarding transcriptional and signaling systems of the lung. The review illustrates that antenatal hypoxic stress can induce a continuum of responses depending on the species examined. Fetuses and newborns of certain species and specific human populations are well acclimated to antenatal hypoxia. However, antenatal hypoxia causes pulmonary vascular disease in fetuses and newborns of most mammalian species and humans. Disease can range from mild pulmonary hypertension, to severe vascular remodeling and dangerous elevations in pressure. The timing, length, and magnitude of the intrauterine hypoxic stress are important to disease development, however there is also a genetic-environmental relationship that is not yet completely understood. Determining the origins of pulmonary vascular remodeling and pulmonary hypertension and their associated effects is a challenging task, but is necessary in order to develop targeted therapies for pulmonary hypertension in the newborn due to antenatal hypoxia that can both treat the symptoms and curtail or reverse disease progression.
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Affiliation(s)
- Demosthenes G Papamatheakis
- Center for Perinatal Biology, Loma Linda University School of Medicine, 11234 Anderson Street, Loma Linda, 92350 CA, USA.
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8
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Llanos AJ, Ebensperger G, Herrera EA, Reyes RV, Moraga FA, Parer JT, Giussani DA. Counterpoint: high altitude is not for the birds! J Appl Physiol (1985) 2012; 111:1515-8. [PMID: 22096208 DOI: 10.1152/japplphysiol.00821.2011a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Aníbal J Llanos
- Laboratorio de Fisiología y Fisiopatología del Desarrollo Programa de Fisiopatología Instituto de Ciencias Biomédicas (ICBM)Facultad de Medicina, Chile
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Llanos AJ, Ebensperger G, Herrera EA, Reyes RV, Cabello G, Díaz M, Giussani DA, Parer JT. The heme oxygenase-carbon monoxide system in the regulation of cardiorespiratory function at high altitude. Respir Physiol Neurobiol 2012; 184:186-91. [PMID: 22595369 DOI: 10.1016/j.resp.2012.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/13/2012] [Accepted: 05/02/2012] [Indexed: 12/01/2022]
Abstract
Pulmonary arterial hypertension is one of the most serious pathologies that can affect the 140 million people living at altitudes over 2500 m. The primary emphasis of this review is pulmonary artery hypertension in mammals (sheep and llamas) at high altitude, with specific focus on the heme oxygenase and carbon monoxide (HO-CO) system. We highlight the fact that the neonatal llama has neither pulmonary artery hypertension nor pulmonary vascular remodeling in the Andean altiplano. These neonates have an enhanced HO-CO system function, increasing the HO-1 protein expression and CO production by the pulmonary vessels, when compared to llamas raised at low altitude, or neonatal sheep raised at high altitude. The neonatal sheep has high altitude pulmonary artery hypertension in spite of enhancement of the NO system, with high eNOS protein expression and NO production by the lung. The gasotransmitters NO and CO are important in the regulation of the pulmonary vascular function at high altitudes in both high altitude acclimatized species, such as the sheep, and high altitude adapted species, such as the llama.
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Affiliation(s)
- Aníbal J Llanos
- Unidad de Fisiología y Fisiopatología Perinatal, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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Stec DE, Vera T, Storm MV, McLemore GR, Ryan MJ. Blood pressure and renal blow flow responses in heme oxygenase-2 knockout mice. Am J Physiol Regul Integr Comp Physiol 2009; 297:R1822-8. [PMID: 19846746 DOI: 10.1152/ajpregu.00319.2009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heme oxygenase (HO) is the enzyme responsible for the breakdown of heme-generating carbon monoxide (CO) and biliverdin in this process. HO-2 is the constitutively expressed isoform in most tissues, such as the kidney and vasculature. CO generated by HO is believed to be an important vasodilator in the renal circulation along with another gas, nitric oxide (NO). To determine the importance of HO-2 in the regulation of blood pressure and renal blood flow (RBF), we treated HO-2 knockout (KO) mice chronically with either ANG II or N(G)-nitroarginine methyl ester (l-NAME). Basal blood pressures were not different between wild-type (WT), heterozygous (HET), or KO mice and averaged 113 +/- 3 vs. 115 +/- 2 vs. 116 +/- 2 mmHg. Similar increases in blood pressure to chronic ANG II as well as l-NAME treatment were observed in all groups with blood pressures increasing an average of 30 mmHg in response to ANG II and 15 mmHg in response to l-NAME. Basal RBFs were not different between the groups averaging 6.0 +/- 0.5 (n = 6) vs. 4.8 +/- 0.6 (n = 10) vs. 5.8 +/- 0.7 (n = 6) ml*min(-1)*g(-1) kidney weight in WT, HET, and KO mice. HO-2 KO and HET mice exhibited an attenuated decrease in RBF in response to acute administration of ANG II, while no differences were observed with l-NAME. Our data indicate that blood pressure and RBF responses to increased ANG II or inhibition of nitric oxide are not significantly enhanced in HO-2 KO mice.
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Affiliation(s)
- David E Stec
- Department of Physiology and Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, Mississippi 39215, USA.
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Roth M, Rupp M, Hofmann S, Mittal M, Fuchs B, Sommer N, Parajuli N, Quanz K, Schubert D, Dony E, Schermuly RT, Ghofrani HA, Sausbier U, Rutschmann K, Wilhelm S, Seeger W, Ruth P, Grimminger F, Sausbier M, Weissmann N. Heme Oxygenase-2 and Large-Conductance Ca2+-activated K+Channels. Am J Respir Crit Care Med 2009; 180:353-64. [DOI: 10.1164/rccm.200806-848oc] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Despite modern practices in critical care medicine, sepsis or systemic inflammatory response syndrome remains a leading cause of morbidity and mortality in the intensive care unit. Thus, the need to identify new therapeutic tools for the treatment of sepsis is urgent. In this context, carbon monoxide has become a promising therapeutic molecule that can potentially prevent uncontrolled inflammation in sepsis. In humans, carbon monoxide arises endogenously from the degradation of heme by heme oxygenase enzymes. Both endogenously synthesized and exogenously applied carbon monoxide can exert antiinflammatory and antiapoptotic effects in cells and tissues. Based on these properties, carbon monoxide, when applied at low concentration, conferred protection in a variety of cellular and rodent models of sepsis, and furthermore reduced morbidity and mortality in vivo. Therefore, application of carbon monoxide may have a major impact on the future of sepsis treatment. This review summarizes evidence for salutary effects of carbon monoxide in sepsis of various organs, including lung, heart, kidney, liver, and intestine, and discusses the potential translation of the data into human clinical trials.
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Affiliation(s)
- Alexander Hoetzel
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, The University of Pittsburgh School of Medicine, MUH 628 NW, 3459 Fifth Ave, Pittsburgh, Pennsylvania 15213, USA
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Abstract
Carbon monoxide (CO) is much more than just a toxic gas. Carbon monoxide is produced endogenously by the enzyme heme oxygenase and has important functions under physiological and pathophysiological conditions. Recent studies suggested antioxidative, anti-inflammatory, antiproliferative, anti-apoptotic, and vasodilating characteristics. Regarding clinically-relevant diseases in anesthesiology and critical care medicine, such as adult respiratory distress syndrome (ARDS), sepsis, or during organ transplantation, cytoprotective properties have been demonstrated by low-dose CO in experimental models. In view of a potential CO application in future human studies, this review discusses what is known to date about CO as it relates to functional, protective and toxic aspects.
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Affiliation(s)
- A Hoetzel
- Department of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, W640 Montefiore University Hospital, 3459 Fifth Avenue, Pittsburgh PA 15213, USA.
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Sun B, Sun H, Liu C, Shen J, Chen Z, Chen X. Role of CO-releasing molecules liberated CO in attenuating leukocytes sequestration and inflammatory responses in the lung of thermally injured mice. J Surg Res 2007; 139:128-35. [PMID: 17292406 DOI: 10.1016/j.jss.2006.08.032] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2006] [Revised: 08/07/2006] [Accepted: 08/29/2006] [Indexed: 12/27/2022]
Abstract
BACKGROUND Acute lung injury and pulmonary inflammatory responses are important complications most frequently encountered in severely burned patients. Polymorphonuclear leukocyte (PMN) sequestration and the subsequent generation of oxidants and inflammatory mediators play the key roles in the pathogenesis of acute lung injury. In this study, we used CO-releasing molecules (CORM-2) to determine whether the CO-releasing molecules-liberated CO could attenuate leukocytes sequestration and the inflammatory response in the lung of thermally injured mice. MATERIALS AND METHODS Fifty-four mice were assigned to three groups in three respective experiments. In each experiment, mice in sham group (n=6) underwent sham thermal injury, whereas mice in the burn group (n=6) received 15% total body surface area (TBSA) full-thickness thermal injury and mice in CORM-2 group (n=6) underwent the same thermal injury with immediate administration of CORM-2 (8 mg/kg, i.v.). PMN accumulation (MPO assay) in mice lungs and tumor necrosis factor-alpha and interleukin-1beta in BAL fluid, pulmonary edema formation, and wet/dry weight ratios of lung were determined. Activation of NF-kappaB and expression level of ICAM-1 in the lung was assessed. In in vitro experiment, PMN adhesion to experimental mice serum-stimulated mouse lung endothelial cells (MLEC) was assessed. RESULTS Treatment of thermally injured mice with CORM-2 attenuated PMN accumulation and prevented activation of NF-kappaB in the lung. This was accompanied by a decrease of the expression of ICAM-1. In parallel, PMN adhesion to MLEC stimulated by CORM-2-treated thermally injured mice serum was markedly decreased. Also, CORM-2 markedly decreased the production of inflammatory mediators in BAL fluid without suppressing the permeability of pulmonary microcirculation. CONCLUSIONS CORM-released CO attenuates the inflammatory response in the lung of thermally injured mice by decreasing leukocyte sequestration and interfering with NF-kappaB activation, protein expression of ICAM-1, and therefore, suppressing endothelial cells' pro-adhesive phenotype.
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Affiliation(s)
- Bingwei Sun
- Department of Burns and Plastic Surgery, Affiliated Hospital, Jiangsu University, Zhenjiang, Jiangsu Province, People's Republic of China.
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Kinobe RT, Vlahakis JZ, Soong JM, Szarek WA, Brien JF, Longo LD, Nakatsu K. Heme oxygenase activity in fetal and adult sheep is not altered by acclimatization to high altitude hypoxia. Can J Physiol Pharmacol 2006; 84:893-901. [PMID: 17111034 DOI: 10.1139/y06-034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxic stress has been reported to induce the expression of stress proteins such as heme oxygenase (HO), which catalyze the breakdown of heme to generate biliverdin, ferrous iron, and carbon monoxide. These degradation products play a role in the regulation of a variety of processes such as vascular tone, inflammation, and central nervous system function. In mammals, there are 2 catalytically functional HO isozymes, HO-1 (inducible) and HO-2 (constitutive). HO-1 expression is regulated by an array of nonphysiological and physiological stimuli including acute hypoxemia. As relatively little is known of the HO response to prolonged hypoxia in whole animals other than small laboratory rodents, the aim of this work was to examine the effect of long-term hypoxia on total HO activity in fetal and adult ovine tissue. Sheep were maintained at high altitude (3820 m), after which the following tissues were harvested from near-term fetal and non-pregnant ewes for in vitro measurement of HO activity: left ventricle, renal papilla, lung apex, pulmonary artery, carotid artery, mesenteric artery, placental cotyledon, spleen, and brain frontal cortex. There were no significant differences between HO activities in tissues from hypoxic fetal and adult sheep compared with their normoxic controls. Fetal heart HO activities were higher than those of adult tissue (p < 0.05), whereas adult spleen HO activity was significantly higher than that of fetal tissue (p < 0.05). In conclusion, these data indicate that long-term exposure to high altitude hypoxia does not have a persistent effect on HO activity in ovine tissues. Also, except for the spleen where there is a high expression of HO-1 under normal conditions, tissue HO activity is correlated with the expression of HO-2, the constitutive isozyme.
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Affiliation(s)
- Robert T Kinobe
- Department of Pharmacology and Toxicology, Queen's University, Kingston, Ontario K7L 3N6, Canada
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Aberg AM, Hultin M, Abrahamsson P, Larsson JE. Circulatory effects and kinetics following acute administration of carbon monoxide in a porcine model. Life Sci 2004; 75:1029-39. [PMID: 15207651 DOI: 10.1016/j.lfs.2003.12.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2003] [Accepted: 12/12/2003] [Indexed: 10/26/2022]
Abstract
Carbon monoxide is produced in the endothelial cells and has possible vasodilator activity through three different pathways. The aim of this study was to demonstrate circulatory effects after administration of saturated carbon monoxide blood and to describe the pharmacokinetics of carbon monoxide. Six pigs were anesthetized and 150 ml blood was removed. This blood was bubbled with carbon monoxide until the carboxyhemoglobin (COHb) levels were 90-99%. A specific amount of this blood was then injected back to the animal. At predetermined times; arterial and mixed venous blood was drawn and analyzed for carbon monoxide. Systemic and pulmonary vascular resistance index (SVRi and PVRi) were measured and exhaled air was sampled and measured for carbon monoxide. Blood samples were gathered over 300 minutes along with measurements of invasive pressures, heart rate, cardiac output, oxygen saturation (SpO2), Hb, temperature and blood gases. We conclude that this type of exposure to carbon monoxide appears to have little or no effect on general vasomotor tone and, after correcting for basal levels of carbon monoxide, elimination occurs through the lungs as predicted by a single compartment model. The half-life of carbon monoxide was determined to be 60.5 minutes (SEM 4.7).
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Affiliation(s)
- Anna-Maja Aberg
- Department of Surgical and Perioperative Sciences, Division of Anesthesiology and Intensive Care, Umea University Hospital, SE-901 85 Umea, Sweden.
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17
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Westphal M, Morita N, Enkhbaatar P, Murakami K, Traber L, Traber DL. Carboxyhemoglobin formation following smoke inhalation injury in sheep is interrelated with pulmonary shunt fraction. Biochem Biophys Res Commun 2004; 311:754-8. [PMID: 14623337 DOI: 10.1016/j.bbrc.2003.10.063] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Carboxyhemoglobin (COHb) formation is triggered by the inducible isoform of heme oxygenase (HO-1) catalyzing carbon monoxide (CO) production through breakdown of heme molecules, exposure to CO or both. In the setting of CO poisoning, COHb is regarded as a reliable marker characterizing both severity of injury and efficacy of treatment strategies. This study was designed as a prospective laboratory experiment to elucidate potential interdependencies between COHb generation, oxygenation, and pulmonary shunt fraction (Qs/Qt) in an ovine model of smoke inhalation injury. Chronically instrumented ewes (n=15) were repeatedly subjected to cotton smoke (4 x 12 breaths) according to an established protocol. This approach resulted in a progressive increase in COHb formation that was interrelated with the degree of Qs/Qt (P<0.001) and inversely correlated with both arterial and mixed venous HbO(2) saturation (r=-0.96 and -0.93). Although the arteriovenous COHb gradient successively decreased over time, COHb determined in venous blood underestimated the arterial content.
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Affiliation(s)
- Martin Westphal
- Department of Investigational Intensive Care Unit and Shriners Hospital for Children, University of Texas Medical Branch, Galveston, TX, USA.
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