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González-Candia A, Candia AA, Arias PV, Paz AA, Herrera EA, Castillo RL. Chronic intermittent hypobaric hypoxia induces cardiovascular dysfunction in a high-altitude working shift model. Life Sci 2023:121800. [PMID: 37245841 DOI: 10.1016/j.lfs.2023.121800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/17/2023] [Accepted: 05/20/2023] [Indexed: 05/30/2023]
Abstract
AIMS Chronic intermittent hypobaric hypoxia (CIHH) exposure due to shift work occurs mainly in 4 × 4 or 7 × 7 days shifts in mining, astronomy, and customs activities, among other institutions. However, the long-lasting effects of CIHH on cardiovascular structure and function are not well characterized. We aimed to investigate the effects of CIHH on the cardiac and vascular response of adult rats simulating high-altitude (4600 m) x low-altitude (760 m) working shifts. MAIN METHODS We analyzed in vivo cardiac function through echocardiography, ex vivo vascular reactivity by wire myography, and in vitro cardiac morphology by histology and protein expression and immunolocalization by molecular biology and immunohistochemistry techniques in 12 rats, 6 exposed to CIHH in the hypoxic chamber, and respective normobaric normoxic controls (n = 6). KEY FINDINGS CIHH induced cardiac dysfunction with left and right ventricle remodeling, associated with an increased collagen content in the right ventricle. In addition, CIHH increased HIF-1α levels in both ventricles. These changes are associated with decreased antioxidant capacity in cardiac tissue. Conversely, CIHH decreased contractile capacity with a marked decreased in nitric oxide-dependent vasodilation in both, carotid and femoral arteries. SIGNIFICANCE These data suggest that CIHH induces cardiac and vascular dysfunction by ventricular remodeling and impaired vascular vasodilator function. Our findings highlight the impact of CIHH in cardiovascular function and the importance of a periodic cardiovascular evaluation in high-altitude workers.
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Affiliation(s)
| | - Alejandro A Candia
- Institute of Health Sciences, University of O'Higgins, Rancagua, Chile; Department for the Woman and Newborn Health Promotion, Universidad de Chile, Chile
| | - Pamela V Arias
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Adolfo A Paz
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Emilio A Herrera
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile; International Center for Andean Studies (INCAS), University of Chile, Putre, Chile.
| | - Rodrigo L Castillo
- Departamento de Medicina Interna Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Unidad de Paciente Crítico, Hospital del Salvador, Santiago, Chile.
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Candia AA, Jiménez T, Navarrete Á, Beñaldo F, Silva P, García-Herrera C, Sferruzzi-Perri AN, Krause BJ, González-Candia A, Herrera EA. Developmental Ultrasound Characteristics in Guinea Pigs: Similarities with Human Pregnancy. Vet Sci 2023; 10:vetsci10020144. [PMID: 36851448 PMCID: PMC9963037 DOI: 10.3390/vetsci10020144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/27/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND Biometrical and blood flow examinations are fundamental for assessing fetoplacental development during pregnancy. Guinea pigs have been proposed as a good model to study fetal development and related gestational complications; however, longitudinal growth and blood flow changes in utero have not been properly described. This study aimed to describe fetal and placental growth and blood flow of the main intrauterine vascular beds across normal guinea pig pregnancy and to discuss the relevance of this data for human pregnancy. METHODS Pregnant guinea pigs were studied from day 25 of pregnancy until term (day ~70) by ultrasound and Doppler assessment. The results were compared to human data from the literature. RESULTS Measurements of biparietal diameter (BPD), cranial circumference (CC), abdominal circumference, and placental biometry, as well as pulsatility index determination of umbilical artery, middle cerebral artery (MCA), and cerebroplacental ratio (CPR), were feasible to determine across pregnancy, and they could be adjusted to linear or nonlinear functions. In addition, several of these parameters showed a high correlation coefficient and could be used to assess gestational age in guinea pigs. We further compared these data to ultrasound variables from human pregnancy with high similarities. CONCLUSIONS BPD and CC are the most reliable measurements to assess fetal growth in guinea pigs. Furthermore, this is the first report in which the MCA pulsatility index and CPR are described across guinea pig gestation. The guinea pig is a valuable model to assess fetal growth and blood flow distribution, variables that are comparable with human pregnancy.
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Affiliation(s)
- Alejandro A. Candia
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
- Institute of Health Sciences, University of O’Higgins, Rancagua 2841959, Chile
| | - Tamara Jiménez
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
| | - Álvaro Navarrete
- Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Santiago de Chile, Santiago 9170022, Chile
| | - Felipe Beñaldo
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
| | - Pablo Silva
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
| | - Claudio García-Herrera
- Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Santiago de Chile, Santiago 9170022, Chile
| | - Amanda N. Sferruzzi-Perri
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Bernardo J. Krause
- Institute of Health Sciences, University of O’Higgins, Rancagua 2841959, Chile
| | - Alejandro González-Candia
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
- Institute of Health Sciences, University of O’Higgins, Rancagua 2841959, Chile
- Correspondence: (A.G.-C.); (E.A.H.); Tel.: +56-2-3328-6038 (A.G.-C.); +56-2-2977-0543 (E.A.H.)
| | - Emilio A. Herrera
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
- International Center for Andean Studies (INCAS), University of Chile, Putre 1070000, Chile
- Correspondence: (A.G.-C.); (E.A.H.); Tel.: +56-2-3328-6038 (A.G.-C.); +56-2-2977-0543 (E.A.H.)
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Paz AA, González-Candia A. Potential pharmacological target of tight junctions to improve the BBB permeability in neonatal Hypoxic-Ischemic encephalopathy Diseases. Biochem Pharmacol 2023; 207:115356. [PMID: 36455671 DOI: 10.1016/j.bcp.2022.115356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/21/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022]
Abstract
Neonatal encephalopathy (NE) is a pathological condition that describes a neurocognitive malfunction in the newborn that arises from fetal, peripartum, or intrapartum events of multifactorial nature, having a poor prognosis and accounting for an incidence of 5-8 per 1000 live births. Neonatal hypoxic-ischemic encephalopathy (HIE) is one of the most studied paradigms of NE, caused by a scarce cerebral perfusion and oxygen supply during perinatal life. The cerebral hypoxic-ischemic insult promotes a loss of permeability of the blood-brain barrier (BBB), an essential structural intermediary of blood-brain communication. This permeability disruption is associated with an increase in inflammatory cytokines, an increase of adhesion molecules, and oxidative stress which disturb the tight junction (TJ) performance and enable transcytosis and paracellular leakage, ultimately leading to death from brain cells. In this context, TJs proteins are essential to preserving the barrier mechanical stability and signaling that modulates the brain-blood vessel multicellular domains, known as neurovascular units (NVU). Recent studies have proposed different strategies with neuroprotective effects that allow for maintaining or restoring the integrity and permeability of the BBB. This review identifies and discusses regulator mechanisms and novel aspects of TJs in the BBB disruption induced by cerebral hypoxic insults during the perinatal period, evaluating potential pharmacological strategies to safeguard BBB integrity.
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Affiliation(s)
- Adolfo A Paz
- Institute of Health Sciences, University O'Higgins, Rancagua, Chile
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Figueroa EG, Caballero-Román A, Ticó JR, Miñarro M, Nardi-Ricart A, González-Candia A. miRNA nanoencapsulation to regulate the programming of the blood-brain barrier permeability by hypoxia. Curr Res Pharmacol Drug Discov 2022; 3:100129. [PMID: 36568262 PMCID: PMC9780061 DOI: 10.1016/j.crphar.2022.100129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 09/11/2022] [Indexed: 12/27/2022] Open
Abstract
Central nervous system (CNS)-related diseases are difficult to treat as most therapeutic agents they cannot reach the brain tissue, mainly due to the blood-brain barrier (BBB), arguably the tightest barrier between the human body and cerebral parenchyma, which routinely excludes most xenobiotic therapeutics compounds. The BBB is a multicellular complex that structurally forms the neurovascular unit (NVU) and is organized by neuro-endothelial and glial cells. BBB breakdown and dysfunction from the cerebrovascular cells lead to leakages of systemic components from the blood into the CNS, contributing to neurological deficits. Understanding the molecular mechanisms that regulate BBB permeability and disruption is essential for establishing future therapeutic strategies to restore permeability and improve cerebrovascular health. MicroRNAs (miRNAs), a type of small non-coding RNAs, are emerging as an important regulator of BBB integrity by modulating gene expression by targeting mRNA transcripts. miRNAs is implicated in the development and progression of various illnesses. Conversely, nanoparticle carriers offer unprecedented opportunities for cell-specific controlled delivery of miRNAs for therapeutic purposes. In this sense, we present in this graphical review critical evidence in the regulation of cell junction expression mediated by miRNAs induced by hypoxia and for the use of nanoparticles for the delivery of miRNA-based therapeutics in the treatment of BBB permeability.
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Affiliation(s)
- Esteban G. Figueroa
- Laboratory of Fetal Neuroprogramming, Institute of Health Sciences, Universidad de O'Higgins, Rancagua, Chile
| | - Aitor Caballero-Román
- Pharmacy and Pharmaceutical Technology, and Physical Chemistry Department, Faculty of Pharmacy and Food Sciences, University of Barcelona, Avinguda Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Josep R. Ticó
- Pharmacy and Pharmaceutical Technology, and Physical Chemistry Department, Faculty of Pharmacy and Food Sciences, University of Barcelona, Avinguda Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Montserrat Miñarro
- Pharmacy and Pharmaceutical Technology, and Physical Chemistry Department, Faculty of Pharmacy and Food Sciences, University of Barcelona, Avinguda Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Anna Nardi-Ricart
- Pharmacy and Pharmaceutical Technology, and Physical Chemistry Department, Faculty of Pharmacy and Food Sciences, University of Barcelona, Avinguda Joan XXIII, 27-31, 08028, Barcelona, Spain
- Corresponding author. Pharmacy and Pharmaceutical Technology, and Physical Chemistry Department, Faculty of Pharmacy and Food Sciences, University of Barcelona. Avda. Joan XXIII 27-31, 08028, Barcelona, Spain.
| | - Alejandro González-Candia
- Laboratory of Fetal Neuroprogramming, Institute of Health Sciences, Universidad de O'Higgins, Rancagua, Chile
- Corresponding author. Libertador Bernardo O'Higgins 611, Rancagua, Chile.
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González-Candia A, Candia AA, Paz A, Mobarec F, Urbina-Varela R, del Campo A, Herrera EA, Castillo RL. Cardioprotective Antioxidant and Anti-Inflammatory Mechanisms Induced by Intermittent Hypobaric Hypoxia. Antioxidants (Basel) 2022; 11:antiox11061043. [PMID: 35739940 PMCID: PMC9220055 DOI: 10.3390/antiox11061043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/25/2022] Open
Abstract
More than 80 million people live and work (in a chronic or intermittent form) above 2500 masl, and 35 million live in the Andean Mountains. Furthermore, in Chile, it is estimated that 100,000 people work in high-altitude shifts, where stays in the lowlands are interspersed with working visits in the highlands. Acute exposure to high altitude has been shown to induce oxidative stress in healthy human lowlanders due to increased free radical formation and decreased antioxidant capacity. However, intermittent hypoxia (IH) induces preconditioning in animal models, generating cardioprotection. Here, we aim to describe the responses of a cardiac function to four cycles of intermittent hypobaric hypoxia (IHH) in a rat model. The twelve adult Wistar rats were randomly divided into two equal groups, a four-cycle of IHH and a normobaric hypoxic control. Intermittent hypoxia was induced in a hypobaric chamber in four continuous cycles (1 cycle = 4 days of hypoxia + 4 days of normoxia), reaching a barometric pressure equivalent to 4600 m of altitude (428 Torr). At the end of the fourth cycle, cardiac structural and functional variables were also determined by echocardiography; furthermore, cardiac oxidative stress biomarkers (4-Hydroxynonenal, HNE; nitrotyrosine, NT), antioxidant enzymes, and NLRP3 inflammasome panel expression are also determined. Our results show a higher ejection and a shortening fraction of the left ventricle function by the end of the fourth cycle. Furthermore, cardiac tissue presented a decreased expression of antioxidant proteins. However, a decrease in IL-1β, TNF-αn, and oxidative stress markers is observed in IHH compared to normobaric hypoxic controls. Non-significant differences were found in protein levels of NLRP3 and caspase-1. IHH exposure determines structural and functional heart changes. These findings suggest that initial states of IHH are beneficial for cardiovascular function and protection.
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Affiliation(s)
| | - Alejandro A. Candia
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago 7500922, Chile; (A.A.C.); (A.P.); (F.M.)
- Department for the Woman and Newborn Health Promotion, Universidad de Chile, Santiago 7500922, Chile
| | - Adolfo Paz
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago 7500922, Chile; (A.A.C.); (A.P.); (F.M.)
| | - Fuad Mobarec
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago 7500922, Chile; (A.A.C.); (A.P.); (F.M.)
| | - Rodrigo Urbina-Varela
- Laboratorio de Fisiología y Bioenergética Celular, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile; (R.U.-V.); (A.d.C.)
| | - Andrea del Campo
- Laboratorio de Fisiología y Bioenergética Celular, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile; (R.U.-V.); (A.d.C.)
| | - Emilio A. Herrera
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago 7500922, Chile; (A.A.C.); (A.P.); (F.M.)
- International Center for Andean Studies (INCAS), University of Chile, Putre 1070000, Chile
- Correspondence: (E.A.H.); or (R.L.C.); Tel.: +56-982-337-566 (R.L.C.)
| | - Rodrigo L. Castillo
- Departamento de Medicina Interna Oriente, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
- Unidad de Paciente Crítico, Hospital del Salvador, Santiago 7500922, Chile
- Correspondence: (E.A.H.); or (R.L.C.); Tel.: +56-982-337-566 (R.L.C.)
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Castillo RL, González-Candia A, Carrasco R. Editorial: Mechanisms of Ischemia-Reperfusion Injury in Animal Models and Clinical Conditions: Current Concepts of Pharmacological Strategies. Front Physiol 2022; 13:880543. [PMID: 35480034 PMCID: PMC9037684 DOI: 10.3389/fphys.2022.880543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Rodrigo L Castillo
- Department of Internal Medicine, East Division, Faculty of Medicine, University of Chile, Santiago, Chile.,Critical Patient Unit, Hospital Salvador, Santiago, Chile
| | | | - Rodrigo Carrasco
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada
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Utrera A, Navarrete Á, González-Candia A, García-Herrera C, Herrera EA. Biomechanical and structural responses of the aorta to intermittent hypobaric hypoxia in a rat model. Sci Rep 2022; 12:3790. [PMID: 35260626 PMCID: PMC8904842 DOI: 10.1038/s41598-022-07616-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 02/14/2022] [Indexed: 02/07/2023] Open
Abstract
High altitude hypoxia is a condition experienced by diverse populations worldwide. In addition, several jobs require working shifts where workers are exposed to repetitive cycles of hypobaric hypoxia and normobaric normoxia. Currently, few is known about the biomechanical cardiovascular responses of this condition. In the present study, we investigate the cycle-dependent biomechanical effects of intermittent hypobaric hypoxia (IHH) on the thoracic aorta artery, in terms of both structure and function. To determine the vascular effects of IHH, functional, mechanical and histological approaches were carried out in the thoracic aorta artery, using uniaxial, pre-stretch, ring opening, myography, and histological tests. Three groups of rats were established: control (normobaric normoxia, NN), 4-cycles of intermittent hypoxia (short-term intermittent hypobaric hypoxia, STH), and 10-cycles of intermittent hypoxia (long-term intermittent hypobaric hypoxia, LTH). The pre-stretch and ring opening tests, aimed at quantifying residual strains of the tissues in longitudinal and circumferential directions, showed that the hypoxia condition leads to an increase in the longitudinal stretch and a marked decrease of the circumferential residual strain. The uniaxial mechanical tests were used to determine the elastic properties of the tissues, showing that a general stiffening process occurs during the early stages of the IH (STH group), specially leading to a significative increase in the high strain elastic modulus ([Formula: see text]) and an increasing trend of low strain elastic modulus ([Formula: see text]). In contrast, the LTH group showed a more control-like mechanical behavior. Myography test, used to assess the vasoactive function, revealed that IH induces a high sensitivity to vasoconstrictor agents as a function of hypoxic cycles. In addition, the aorta showed an increased muscle-dependent vasorelaxation on the LTH group. Histological tests, used to quantify the elastic fiber, nuclei, and geometrical properties, showed that the STH group presents a state of vascular fibrosis, with a significant increase in elastin content, and a tendency towards an increase in collagen fibers. In addition, advanced stages of IH (LTH), showed a vascular remodeling effect with a significant increase of internal and external diameters. Considering all the multidimensional vascular effects, we propose the existence of a long-term passive adaptation mechanism and vascular dysfunction as cycle-dependent effects of intermittent exposures to hypobaric hypoxia.
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Affiliation(s)
- Andrés Utrera
- Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, Santiago, Chile
| | - Álvaro Navarrete
- Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, Santiago, Chile
| | | | | | - Emilio A Herrera
- Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile. .,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile.
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Candia AA, Arias PV, González-Candia C, Navarrete A, Ebensperger G, Reyes RV, Llanos AJ, González-Candia A, Herrera EA. Melatonin treatment during chronic hypoxic gestation improves neonatal cerebrovascular function. Vascul Pharmacol 2022; 144:106971. [PMID: 35150933 DOI: 10.1016/j.vph.2022.106971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/13/2022] [Accepted: 02/06/2022] [Indexed: 01/20/2023]
Abstract
BACKGROUND Fetal chronic hypoxia is associated with blood flow redistribution and oxidative damage in the brain, leading to increased perinatal morbimortality. Melatonin reduces oxidative stress, improves vascular function, and has neuroprotective effects. OBJECTIVES This study aimed to determine the effects of an oral melatonin treatment to pregnant ewes at high-altitude, on the cerebrovascular function of their neonates. STUDY DESIGN Ten high-altitude pregnant sheep received either vehicle or melatonin (10 mg/d) during the last third of gestation until delivery. Postnatal daily hemodynamic measurements were recorded from lambs until 12 days old. In addition, lambs were submitted to a graded oxygenation protocol to assess cerebrovascular responses. Subsequently, lambs were euthanized, and middle cerebral arteries (MCA) were collected for vascular function, protein levels, and morphostructural analyses. RESULTS Antenatal treatment doubled plasma levels of melatonin in pregnant ewes. Melatonin increased carotid flow and decreased carotid vascular resistance in the lambs by the end of the first week. Furthermore, melatonin increased MCA's maximal vasoconstrictor and vasodilator responses, associated with nitric oxide-dependent and independent mechanisms. CONCLUSIONS An oral treatment with melatonin during pregnancy promotes postnatal cerebral perfusion in chronically hypoxic neonates. Melatonin is a potential treatment for cerebrovascular dysfunction due to perinatal chronic hypoxia.
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Affiliation(s)
- Alejandro A Candia
- Vascular Function & Reactivity Lab, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Chile; Department for the Woman and Newborn Health Promotion, Universidad de Chile, Santiago, Chile
| | - Pamela V Arias
- Vascular Function & Reactivity Lab, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Chile
| | - Cristopher González-Candia
- Vascular Function & Reactivity Lab, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Chile
| | - Alvaro Navarrete
- Department of Mechanical Engineering, Faculty of Engineering, Universidad de Santiago de, Chile, Chile
| | - Germán Ebensperger
- Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile
| | - Roberto V Reyes
- Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile
| | - Aníbal J Llanos
- Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile; International Center for Andean Studies (INCAS), Universidad de Chile, Chile
| | | | - Emilio A Herrera
- Vascular Function & Reactivity Lab, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Chile; International Center for Andean Studies (INCAS), Universidad de Chile, Chile.
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Herrera EA, González-Candia A. Gestational Hypoxia and Blood-Brain Barrier Permeability: Early Origins of Cerebrovascular Dysfunction Induced by Epigenetic Mechanisms. Front Physiol 2021; 12:717550. [PMID: 34489733 PMCID: PMC8418233 DOI: 10.3389/fphys.2021.717550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/19/2021] [Indexed: 01/25/2023] Open
Abstract
Fetal chronic hypoxia leads to intrauterine growth restriction (IUGR), which is likely to reduce oxygen delivery to the brain and induce long-term neurological impairments. These indicate a modulatory role for oxygen in cerebrovascular development. During intrauterine hypoxia, the fetal circulation suffers marked adaptations in the fetal cardiac output to maintain oxygen and nutrient delivery to vital organs, known as the "brain-sparing phenotype." This is a well-characterized response; however, little is known about the postnatal course and outcomes of this fetal cerebrovascular adaptation. In addition, several neurodevelopmental disorders have their origins during gestation. Still, few studies have focused on how intrauterine fetal hypoxia modulates the normal brain development of the blood-brain barrier (BBB) in the IUGR neonate. The BBB is a cellular structure formed by the neurovascular unit (NVU) and is organized by a monolayer of endothelial and mural cells. The BBB regulates the entry of plasma cells and molecules from the systemic circulation to the brain. A highly selective permeability system achieves this through integral membrane proteins in brain endothelial cells. BBB breakdown and dysfunction in cerebrovascular diseases lead to leakage of blood components into the brain parenchyma, contributing to neurological deficits. The fetal brain circulation is particularly susceptible in IUGR and is proposed to be one of the main pathological processes deriving BBB disruption. In the last decade, several epigenetic mechanisms activated by IU hypoxia have been proposed to regulate the postnatal BBB permeability. However, few mechanistic studies about this topic are available, and little evidence shows controversy. Therefore, in this mini-review, we analyze the BBB permeability-associated epigenetic mechanisms in the brain exposed to chronic intrauterine hypoxia.
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Affiliation(s)
- Emilio A Herrera
- Laboratory of Vascular Function and Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
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Figueroa EG, González-Candia A, Caballero-Román A, Fornaguera C, Escribano-Ferrer E, García-Celma MJ, Herrera EA. Blood-brain barrier dysfunction in hemorrhagic transformation: a therapeutic opportunity for nanoparticles and melatonin. J Neurophysiol 2021; 125:2025-2033. [PMID: 33909508 DOI: 10.1152/jn.00638.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Stroke is the second leading cause of death worldwide, estimated that one-sixth of the world population will suffer it once in their life. The most common type of this medical condition is the ischemic stroke (IS), produced by a thrombotic or embolic occlusion of a major cerebral artery or its branches, leading to the formation of a complex infarct region caused by oxidative stress, excitotoxicity, and endothelial dysfunction. Nowadays, the immediate treatment for IS involves thrombolytic agents or mechanical thrombectomy, depending on the integrity of the blood-brain barrier (BBB). A common stroke complication is the hemorrhagic transformation (HT), which consists of bleeding into the ischemic brain area. Currently, better treatments for IS are urgently needed. As such, the neurohormone melatonin has been proposed as a good candidate due to its antioxidant, anti-inflammatory, and neuroprotective effects, particularly against lipid peroxidation and oxidative stress during brain ischemia. Here, we proposed to develop intravenous or intranasal melatonin nanoformulation to specifically target the brain in patients with stroke. Nowadays, the challenge is to find a formulation able to cross the barriers and reach the target organ in an effective dose to generate the pharmacological effect. In this review, we discuss the current literature about stroke pathophysiology, melatonin properties, and its potential use in nanoformulations as a novel therapeutic approach for ischemic stroke.
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Affiliation(s)
- Esteban G Figueroa
- Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry, R+D Associated Unit to Consejo Superior de Investigaciones Científicas (CSIC), Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain.,Institute of Nanoscience and Nanotechnology, University of Barcelona, Barcelona, Spain
| | - Alejandro González-Candia
- Institute of Health Sciences, University of O'Higgins, Rancagua, Chile.,Laboratory of Vascular Function and Reactivity, Pathophysiology Program, Instituto de Ciencias Biomédicas (ICBM), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Aitor Caballero-Román
- Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry, R+D Associated Unit to Consejo Superior de Investigaciones Científicas (CSIC), Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain
| | - Cristina Fornaguera
- Grup d'Enginyeria de Materials, Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Elvira Escribano-Ferrer
- Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry, R+D Associated Unit to Consejo Superior de Investigaciones Científicas (CSIC), Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain.,Institute of Nanoscience and Nanotechnology, University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red (CIBER) Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain
| | - María José García-Celma
- Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry, R+D Associated Unit to Consejo Superior de Investigaciones Científicas (CSIC), Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain.,Institute of Nanoscience and Nanotechnology, University of Barcelona, Barcelona, Spain.,Center for Biomedical Research Network in Bioengineering, Biomaterials and Nanomedicine, Barcelona, Spain
| | - Emilio A Herrera
- Laboratory of Vascular Function and Reactivity, Pathophysiology Program, Instituto de Ciencias Biomédicas (ICBM), Faculty of Medicine, University of Chile, Santiago, Chile.,International Center for Andean Studies, University of Chile, Putre, Chile
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Rivera E, García-Herrera C, González-Candia A, Celentano DJ, Herrera EA. Effects of melatonin on the passive mechanical response of arteries in chronic hypoxic newborn lambs. J Mech Behav Biomed Mater 2020; 112:104013. [PMID: 32846285 DOI: 10.1016/j.jmbbm.2020.104013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 04/15/2020] [Accepted: 07/26/2020] [Indexed: 02/07/2023]
Abstract
Chronic hypoxia is a condition that increases the cardiovascular complications of newborns gestated and born at high altitude (HA), over 2500 m above sea level (masl). A particularly complex pathology is pulmonary arterial hypertension of the neonate (PHN), which is increased at HA due to hypobaric hypoxia. Basic and clinical research have recognized that new treatments are needed, because current ones are, in general, palliative and with low effectiveness. Therefore, recently we have proposed melatonin as a potential adjuvant treatment to improve cardiopulmonary function. However, melatonin effects on the mechanical response of the arteries and their microstructure are not known. This study assesses the effects of a neonatal treatment with daily low doses of melatonin on the passive biomechanical behavior of the aorta artery and main pulmonary artery of PHN lambs born in chronic hypobaric hypoxia (at 3600 masl). With this purpose, ex-vivo measurements were made on axial stretch, tensile and opening ring tests together with a histological analysis to explore the morphometry and microstructure of the arteries. Our results show that the passive mechanical properties of the aorta artery and main pulmonary artery of lambs do not seem to be affected by a treatment based on low melatonin doses. However, we found evidence that melatonin has microstructural effects, particularly, diminishing cell proliferation, which is an indicator of antiremodeling capacity. Therefore, the use of melatonin as an adjuvant against pathologies like PHN would present antiproliferative effect at the microstructural level, keeping the macroscopic properties of the aorta artery and main pulmonary artery.
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Affiliation(s)
- Eugenio Rivera
- Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, Av. Bernardo O'Higgins, 3363, Santiago de Chile, Chile
| | - Claudio García-Herrera
- Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, Av. Bernardo O'Higgins, 3363, Santiago de Chile, Chile.
| | - Alejandro González-Candia
- International Center for Andean Studies (INCAS), Universidad de Chile, Baquedano S/n, Putre, Chile; Institute of Health Sciences, University of O'Higgins, Libertador Bernardo O'Higgins 611, Rancagua, Chile
| | - Diego J Celentano
- Departamento de Ingeniería Mecánica y Metalúrgica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago de Chile, Chile
| | - Emilio A Herrera
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, ICBM, Universidad de Chile, Av. Salvador 486, Santiago de Chile, Chile; International Center for Andean Studies (INCAS), Universidad de Chile, Baquedano S/n, Putre, Chile
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12
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Aguilar SA, Arias PV, Canquil I, Ebensperger G, Llanos AJ, Reyes RV, González-Candia A, Herrera EA. [Melatonin modulates the expression of pulmonary prostanoids]. Rev Med Chil 2019; 147:281-288. [PMID: 31344164 DOI: 10.4067/s0034-98872019000300281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/01/2019] [Indexed: 11/17/2022]
Abstract
BACKGROUND Living above 2,500 meters in hypobaric conditions induces pulmonary arterial hypertension of the neonate (PAHN), a syndrome whose main features are: pathological remodeling of the pulmonary vessels, abnormal vascular reactivity and increased oxidative stress. Melatonin could have pulmonary antioxidant, anti-remodeling and vasodilating properties for this condition. AIM To determine the effect of melatonin at the transcript level of prostanoid pathways in the lung of neonatal lambs gestated and born under hypobaric hypoxia. MATERIAL AND METHODS Vehicle (1.4% of ethanol, n = 6) or melatonin (1 mg * kg1, n = 5) were administered from the postnatal day 4 to 21 to lambs gestated and born at 3,600 meters above sea level. After one week of treatment completion, lung tissue was obtained, the transcript and protein levels of prostanoid synthases and receptors were assessed by RT-PCR and Western Blot. RESULTS Melatonin induced the expression of prostacyclin synthase transcript and increased protein expression of the prostacyclin receptor. In addition, the treatment decreased the expression of transcript and protein of cyclooxygenase-2, without changes in the expression of the prostanoid vasoconstrictor (thromboxane) pathway. CONCLUSIONS Postnatal treatment with melatonin increases the expression of the prostacyclin-vasodilator pathway without changing the vasoconstrictor thromboxane pathway. Further, the decreased COX-2 induced by melatonin could be an index of lesser oxidative stress and inflammation in the lung.
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Affiliation(s)
- Simón A Aguilar
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Pamela V Arias
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ignacio Canquil
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Germán Ebensperger
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Aníbal J Llanos
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Roberto V Reyes
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | | | - Emilio A Herrera
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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13
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Astorga CR, González-Candia A, Candia AA, Figueroa EG, Cañas D, Ebensperger G, Reyes RV, Llanos AJ, Herrera EA. Melatonin Decreases Pulmonary Vascular Remodeling and Oxygen Sensitivity in Pulmonary Hypertensive Newborn Lambs. Front Physiol 2018; 9:185. [PMID: 29559926 PMCID: PMC5845624 DOI: 10.3389/fphys.2018.00185] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/20/2018] [Indexed: 12/16/2022] Open
Abstract
Background: Chronic hypoxia and oxidative stress during gestation lead to pulmonary hypertension of the neonate (PHN), a condition characterized by abnormal pulmonary arterial reactivity and remodeling. Melatonin has strong antioxidant properties and improves pulmonary vascular function. Here, we aimed to study the effects of melatonin on the function and structure of pulmonary arteries from PHN lambs. Methods: Twelve lambs (Ovis aries) gestated and born at highlands (3,600 m) were instrumented with systemic and pulmonary catheters. Six of them were assigned to the control group (CN, oral vehicle) and 6 were treated with melatonin (MN, 1 mg.kg−1.d−1) during 10 days. At the end of treatment, we performed a graded oxygenation protocol to assess cardiopulmonary responses to inspired oxygen variations. Further, we obtained lung and pulmonary trunk samples for histology, molecular biology, and immunohistochemistry determinations. Results: Melatonin reduced the in vivo pulmonary pressor response to oxygenation changes. In addition, melatonin decreased cellular density of the media and diminished the proliferation marker KI67 in resistance vessels and pulmonary trunk (p < 0.05). This was associated with a decreased in the remodeling markers α-actin (CN 1.28 ± 0.18 vs. MN 0.77 ± 0.04, p < 0.05) and smoothelin-B (CN 2.13 ± 0.31 vs. MN 0.88 ± 0.27, p < 0.05). Further, melatonin increased vascular density by 134% and vascular luminal surface by 173% (p < 0.05). Finally, melatonin decreased nitrotyrosine, an oxidative stress marker, in small pulmonary vessels (CN 5.12 ± 0.84 vs. MN 1.14 ± 0.34, p < 0.05). Conclusion: Postnatal administration of melatonin blunts the cardiopulmonary response to hypoxia, reduces the pathological vascular remodeling, and increases angiogenesis in pulmonary hypertensive neonatal lambs.These effects improve the pulmonary vascular structure and function in the neonatal period under chronic hypoxia.
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Affiliation(s)
- Cristian R Astorga
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Alejandro González-Candia
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Alejandro A Candia
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Department for the Woman and Newborn Health Promotion, Universidad de Chile, Santiago, Chile
| | - Esteban G Figueroa
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Daniel Cañas
- Department of Mechanical Engineering, Faculty of Engineering, Universidad de Santiago de Chile, Santiago, Chile
| | - Germán Ebensperger
- Perinatal Physiology and Pathophysiology Unit, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies, Universidad de Chile, Santiago, Chile
| | - Roberto V Reyes
- Perinatal Physiology and Pathophysiology Unit, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies, Universidad de Chile, Santiago, Chile
| | - Aníbal J Llanos
- Perinatal Physiology and Pathophysiology Unit, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies, Universidad de Chile, Santiago, Chile
| | - Emilio A Herrera
- Laboratory of Vascular Function & Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Perinatal Physiology and Pathophysiology Unit, Pathophysiology Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies, Universidad de Chile, Santiago, Chile
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14
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Aguilar M, González-Candia A, Rodríguez J, Carrasco-Pozo C, Cañas D, García-Herrera C, Herrera EA, Castillo RL. Mechanisms of Cardiovascular Protection Associated with Intermittent Hypobaric Hypoxia Exposure in a Rat Model: Role of Oxidative Stress. Int J Mol Sci 2018; 19:ijms19020366. [PMID: 29373484 PMCID: PMC5855588 DOI: 10.3390/ijms19020366] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 12/25/2022] Open
Abstract
More than 140 million people live and works (in a chronic or intermittent form) above 2500 m worldwide and 35 million live in the Andean Mountains. Furthermore, in Chile, it is estimated that 55,000 persons work in high altitude shifts, where stays at lowlands and interspersed with working stays at highlands. Acute exposure to high altitude has been shown to induce oxidative stress in healthy human lowlanders, due to an increase in free radical formation and a decrease in antioxidant capacity. However, in animal models, intermittent hypoxia (IH) induce preconditioning, like responses and cardioprotection. Here, we aimed to describe in a rat model the responses on cardiac and vascular function to 4 cycles of intermittent hypobaric hypoxia (IHH). Twelve adult Wistar rats were randomly divided into two equal groups, a four-cycle of IHH, and a normobaric hypoxic control. Intermittent hypoxia was induced in a hypobaric chamber in four continuous cycles (1 cycle = 4 days hypoxia + 4 days normoxia), reaching a barometric pressure equivalent to 4600 m of altitude (428 Torr). At the end of the first and fourth cycle, cardiac structural, and functional variables were determined by echocardiography. Thereafter, ex vivo vascular function and biomechanical properties were determined in femoral arteries by wire myography. We further measured cardiac oxidative stress biomarkers (4-Hydroxy-nonenal, HNE; nytrotirosine, NT), reactive oxygen species (ROS) sources (NADPH and mitochondrial), and antioxidant enzymes activity (catalase, CAT; glutathione peroxidase, GPx, and superoxide dismutase, SOD). Our results show a higher ejection and shortening fraction of the left ventricle function by the end of the 4th cycle. Further, femoral vessels showed an improvement of vasodilator capacity and diminished stiffening. Cardiac tissue presented a higher expression of antioxidant enzymes and mitochondrial ROS formation in IHH, as compared with normobaric hypoxic controls. IHH exposure determines a preconditioning effect on the heart and femoral artery, both at structural and functional levels, associated with the induction of antioxidant defence mechanisms. However, mitochondrial ROS generation was increased in cardiac tissue. These findings suggest that initial states of IHH are beneficial for cardiovascular function and protection.
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Affiliation(s)
- Miguel Aguilar
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
| | - Alejandro González-Candia
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
| | - Jorge Rodríguez
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
- Departamento de Kinesiología, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
| | - Catalina Carrasco-Pozo
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4222, Australia.
- Departamento de Nutrición, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
| | - Daniel Cañas
- Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Santiago de Chile, Santiago 9170125, Chile.
| | - Claudio García-Herrera
- Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Santiago de Chile, Santiago 9170125, Chile.
| | - Emilio A Herrera
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
- International Center for Andean Studies, Universidad de Chile, Putre, Chile.
| | - Rodrigo L Castillo
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile.
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15
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González-Candia A, Veliz M, Araya C, Quezada S, Ebensperger G, Serón-Ferré M, Reyes RV, Llanos AJ, Herrera EA. Potential adverse effects of antenatal melatonin as a treatment for intrauterine growth restriction: findings in pregnant sheep. Am J Obstet Gynecol 2016; 215:245.e1-7. [PMID: 26902986 DOI: 10.1016/j.ajog.2016.02.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 02/05/2016] [Accepted: 02/16/2016] [Indexed: 12/26/2022]
Abstract
BACKGROUND Intrauterine growth restriction is a condition in which the fetus has a birthweight and/or length <10th percentile for the gestational age. Intrauterine growth restriction can be associated with various causes, among which is low uteroplacental perfusion and chronic hypoxia during gestation. Often, intrauterine growth-restricted fetuses have increased oxidative stress; therefore, agents that decrease oxidative stress and increase utero, placental, and umbilical perfusion have been proposed as a beneficial therapeutic strategy. In this scenario, melatonin acts as an umbilical vasodilator and a potent antioxidant that has not been evaluated in pregnancies under chronic hypoxia that induce fetal growth restriction. However, this neurohormone has been proposed as a pharmacologic therapy for complicated pregnancies. OBJECTIVES The aim of this study was to determine the effects of prenatal administration of melatonin during the last trimester of pregnancy on the biometry of the growth-restricted lambs because of developmental hypoxia. Further, we aimed to determine melatonin and cortisol levels and oxidative stress markers in plasma of pregnant ewes during the treatment. STUDY DESIGN High-altitude pregnant sheep received either vehicle (n = 5; 5 mL 1.4% ethanol) or melatonin (n = 7; 10 mg/kg(-1)day(-1) in 5 mL 1.4% ethanol) daily during the last one-third of gestation. Maternal plasma levels of melatonin, cortisol, antioxidant capacity, and oxidative stress were determined along treatment. At birth, neonates were examined, weighed, and measured (biparietal diameter, abdominal diameter, and crown-rump length). RESULTS Antenatal treatment with melatonin markedly decreased neonatal biometry and weight at birth. Additionally, melatonin treatment increased the length of gestation by 7.5% and shifted the time of delivery. Furthermore, the prenatal treatment doubled plasma levels of melatonin and cortisol and significantly improved the antioxidant capacity of the pregnant ewes. CONCLUSIONS Our findings indicate that antenatal melatonin induces further intrauterine growth restriction but improves the maternal plasma antioxidant capacity. Additional studies should address the efficiency and safety of antenatal melatonin before clinical attempts on humans.
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16
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Torres F, González-Candia A, Montt C, Ebensperger G, Chubretovic M, Serón-Ferré M, Reyes RV, Llanos AJ, Herrera EA. Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep. J Pineal Res 2015; 58:362-73. [PMID: 25736256 DOI: 10.1111/jpi.12222] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 02/26/2015] [Indexed: 12/12/2022]
Abstract
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial- and muscular-dependent pathways. This was associated with an enhanced nitric oxide-dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.
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Affiliation(s)
- Flavio Torres
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Providencia, Santiago, Chile
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Herrera EA, Farías JG, González-Candia A, Short SE, Carrasco-Pozo C, Castillo RL. Ω3 Supplementation and intermittent hypobaric hypoxia induce cardioprotection enhancing antioxidant mechanisms in adult rats. Mar Drugs 2015; 13:838-60. [PMID: 25658050 PMCID: PMC4344605 DOI: 10.3390/md13020838] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/13/2015] [Accepted: 01/16/2015] [Indexed: 01/29/2023] Open
Abstract
Intermittent hypobaric hypoxia (IH) is linked with oxidative stress, impairing cardiac function. However, early IH also activate cardio-protective mechanisms. Omega 3 fatty acids (Ω3) induce cardioprotection by reducing infarct size and reinforcing antioxidant defenses. The aim of this work was to determine the combined effects of IH and Ω3 on cardiac function; oxidative balance and inflammatory state. Twenty-eight rats were randomly divided into four groups: normobaric normoxia (N); N + Ω3 (0.3 g·kg−1·day−1); IH; and IH + Ω3. IH was induced by 4 intercalate periods of hypoxia (4 days)—normoxia (4 days) in a hypobaric chamber during 32 days. At the end of the exposure, hearts were mounted in a Langendorff system and subjected to 30 min of ischemia followed by 120 min of reperfusion. In addition, we determined HIF-1α and ATP levels, as well as oxidative stress by malondialdehyde and nitrotyrosine quantification. Further, the expression of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase was determined. NF-kappaB and myeloperoxidase levels were assessed in the hearts. Relative to N hearts, IH improved left ventricular function (Left ventricular developed pressure: N; 21.8 ± 3.4 vs. IH; 42.8 ± 7.1 mmHg; p < 0.05); reduced oxidative stress (Malondialdehyde: N; 14.4 ± 1.8 vs. IH; 7.3 ± 2.1 μmol/mg prot.; p < 0.05); and increased antioxidant enzymes expression. Supplementation with Ω3 induces similar responses as IH group. Our findings suggest that both, IH and Ω3 in an independent manner, induce functional improvement by antioxidant and anti-inflammatory mechanisms, establishing cardio-protection.
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Affiliation(s)
- Emilio A Herrera
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
| | - Jorge G Farías
- Departamento de Ingeniería Química, Facultad de Ingeniería y Ciencias, Universidad de la Frontera, Temuco 4811230, Chile.
| | - Alejandro González-Candia
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
| | - Stefania E Short
- Departamento de Ingeniería Química, Facultad de Ingeniería y Ciencias, Universidad de la Frontera, Temuco 4811230, Chile.
| | - Catalina Carrasco-Pozo
- Departamento de Nutrición, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
| | - Rodrigo L Castillo
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
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