scholarly journals Melatonin Reduces Oxidative Stress in the Right Ventricle of Newborn Sheep Gestated under Chronic Hypoxia

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1658
Author(s):  
Alejandro Gonzaléz-Candia ◽  
Pamela V. Arias ◽  
Simón A. Aguilar ◽  
Esteban G. Figueroa ◽  
Roberto V. Reyes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Right Ventricle ◽  
Manganese Superoxide Dismutase ◽  
Cardiac Tissue ◽  
Chronic Hypoxia ◽  
Experimental Period ◽  
Health Concern ◽  
Right Ventricle Dysfunction ◽  
Beneficial Effects ◽  
Pulmonary Arterial

Pulmonary arterial hypertension of newborns (PAHN) constitutes a critical condition involving both severe cardiac remodeling and right ventricle dysfunction. One main cause of this condition is perinatal hypoxia and oxidative stress. Thus, it is a public health concern for populations living above 2500 m and in cases of intrauterine chronic hypoxia in lowlands. Still, pulmonary and cardiac impairments in PAHN lack effective treatments. Previously we have shown the beneficial effects of neonatal melatonin treatment on pulmonary circulation. However, the cardiac effects of this treatment are unknown. In this study, we assessed whether melatonin improves cardiac function and modulates right ventricle (RV) oxidative stress. Ten lambs were gestated, born, and raised at 3600 m. Lambs were divided in two groups. One received daily vehicle as control, and another received daily melatonin (1 mg·kg−1·d−1) for 21 days. Daily cardiovascular measurements were recorded and, at 29 days old, cardiac tissue was collected. Melatonin decreased pulmonary arterial pressure at the end of the experimental period. In addition, melatonin enhanced manganese superoxide dismutase and catalase (CAT) expression, while increasing CAT activity in RV. This was associated with a decrease in superoxide anion generation at the mitochondria and NADPH oxidases in RV. Finally, these effects were associated with a marked decrease of oxidative stress markers in RV. These findings support the cardioprotective effects of an oral administration of melatonin in newborns that suffer from developmental chronic hypoxia.

scholarly journals Effects of Apocynin on Heart Muscle Oxidative Stress of Rats with Experimental Diabetes: Implications for Mitochondria

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 335
Author(s):  
Estefanía Bravo-Sánchez ◽  
Donovan Peña-Montes ◽  
Sarai Sánchez-Duarte ◽  
Alfredo Saavedra-Molina ◽  
Elizabeth Sánchez-Duarte ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Sensitivity ◽  
Cardiac Tissue ◽  
Diabetic Rats ◽  
Oxidase Inhibitor ◽  
Beneficial Effects ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Transport Chain ◽  
Male Wistar Rats

Diabetes mellitus (DM) constitutes one of the public health problems today. It is characterized by hyperglycemia through a defect in the β-cells function and/or decreased insulin sensitivity. Apocynin has been tasted acting directly as an NADPH oxidase inhibitor and reactive oxygen species (ROS) scavenger, exhibiting beneficial effects against diabetic complications. Hence, the present study’s goal was to dissect the possible mechanisms by which apocynin could mediate its cardioprotective effect against DM-induced oxidative stress. Male Wistar rats were assigned into 4 groups: Control (C), control + apocynin (C+A), diabetes (D), diabetes + apocynin (D+A). DM was induced with streptozotocin. Apocynin treatment (3 mg/kg/day) was applied for 5 weeks. Treatment significantly decreased blood glucose levels and insulin resistance in diabetic rats. In cardiac tissue, ROS levels were higher, and catalase enzyme activity was reduced in the D group compared to the C group; the apocynin treatment significantly attenuated these responses. In heart mitochondria, Complexes I and II of the electron transport chain (ETC) were significantly enhanced in the D+A group. Total glutathione, the level of reduced glutathione (GSH) and the GSH/ oxidized glutathione (GSSG) ratio were increased in the D+A group. Superoxide dismutase (SOD) and the glutathione peroxidase (GSH-Px) activities were without change. Apocynin enhances glucose uptake and insulin sensitivity, preserving the antioxidant defense and mitochondrial function.

scholarly journals Effects of ovariectomy on antioxidant defence systems in the right ventricle of female rats with pulmonary arterial hypertension induced by monocrotaline

2018 ◽  
Vol 96 (3) ◽  
pp. 295-303 ◽  
Author(s):  
Rafaela Siqueira ◽  
Rafael Colombo ◽  
Adriana Conzatti ◽  
Alexandre Luz de Castro ◽  
Cristina Campos Carraro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pulmonary Arterial Hypertension ◽  
Right Ventricle ◽  
Protein Expression ◽  
Arterial Hypertension ◽  
Female Rats ◽  
Antioxidant Defenses ◽  
Thioredoxin 1 ◽  
Pulmonary Arterial ◽  
The Right

The aim of this study was to evaluate the impact of ovariectomy on oxidative stress in the right ventricle (RV) of female rats with pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). Rats were divided into 4 groups (n = 6 per group): sham (S), sham + MCT (SM), ovariectomized (O), and ovariectomized + MCT (OM). MCT (60 mg·kg−1 i.p.) was injected 1 week after ovariectomy or sham surgery. Three weeks later, echocardiographic analysis and RV catheterisation were performed. RV morphometric, biochemical, and protein expression analysis through Western blotting were done. MCT promoted a slight increase in pulmonary artery pressure, without differences between the SM and OM groups, but did not induce RV hypertrophy. RV hydrogen peroxide increased in the MCT groups, but SOD, CAT, and GPx activities were also enhanced. Non-classical antioxidant defenses diminished in ovariectomized groups, probably due to a decrease in the nuclear factor Nrf2. Hemoxygenase-1 and thioredoxin-1 protein expression was increased in the OM group compared with SM, being accompanied by an elevation in the estrogen receptor β (ER-β). Hemoxygenase-1 and thioredoxin-1 may be involved in the modulation of oxidative stress in the OM group, and this could be responsible for attenuation of PAH and RV remodeling.

scholarly journals Mechanisms of right heart disease in pulmonary hypertension (2017 Grover Conference Series)

2017 ◽  
Vol 8 (1) ◽  
pp. 204589321775312 ◽  
Author(s):  
Kewal Asosingh ◽  
Serpil Erzurum
Keyword(s):  
Heart Disease ◽  
Right Ventricle ◽  
Vascular Remodeling ◽  
Cardiac Tissue ◽  
Direct Consequence ◽  
Right Heart Failure ◽  
Right Heart ◽  
Pulmonary Vascular Remodeling ◽  
Right Ventricle Dysfunction ◽  
The Right

Current dogma is that pathological hypertrophy of the right ventricle is a direct consequence of pulmonary vascular remodeling. However, progression of right ventricle dysfunction is not always lung-dependent. Increased afterload caused by pulmonary vascular remodeling initiates the right ventricle hypertrophy, but determinants leading to adaptive or maladaptive hypertrophy and failure remain unknown. Ischemia in a hypertrophic right ventricle may directly contribute to right heart failure. Rapidly enlarging cardiomyocytes switch from aerobic to anaerobic energy generation resulting in cell growth under relatively hypoxic conditions. Cardiac muscle reacts to an increased afterload by over-activation of the sympathetic system and uncoupling and downregulation of β-adrenergic receptors. Recent studies suggest that β blocker therapy in PH is safe, well tolerated, and preserves right ventricle function and cardiac output by reducing right ventricular glycolysis. Fibrosis, an evolutionary conserved process in host defense and wound healing, is dysregulated in maladaptive cardiac tissue contributing directly to right ventricle failure. Despite several mechanisms having been suggested in right heart disease, the causes of maladaptive cardiac remodeling remain unknown and require further research.

Dietary restriction and fibre supplementation: oxidative stress and metabolic shifting for cardiac health

2003 ◽  
Vol 81 (11) ◽  
pp. 1042-1048 ◽  
Author(s):  
Yeda S Diniz ◽  
Antonio C Cicogna ◽  
Carlos R Padovani ◽  
Maeli D.P Silva ◽  
Luciane A Faine ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dietary Restriction ◽  
Dietary Fibre ◽  
Cardiac Tissue ◽  
Citrate Synthase ◽  
Lipid Hydroperoxide ◽  
Hdl Cholesterol ◽  
Main Process ◽  
Beneficial Effects ◽  
Male Wistar Rats

Dietary modification ought to be the first line of strategy in prevention of the development of cardiac disease. The purpose of this study was to investigate whether dietary restriction, dietary-fibre-enriched diet, and their interactions might affect antioxidant capacity and oxidative stress in cardiac tissue. Male Wistar rats (180–200 g; n = 10) were divided into four groups: control ad libitum diet (C), 50% restricted diet (DR), fed with fibre-enriched diet (F), and 50% restricted fibre-enriched diet (DR-F). After 35 days of the treatments, F, DR, and DR-F rats showed low cholesterol, LDL-cholesterol, and triacylglycerol, and high HDL-cholesterol in serum. The DR, DR-F, and F groups had decreased myocardial lipoperoxide and lipid hydroperoxide. The DR-F and F treatments increased superoxide dismutase and glutatione peroxidase (GSH-Px). The DR treatment increased GSH-Px and catalase activities. Dietary fibre beneficial effects were related to metabolic alterations. The F and DR-F groups showed high cardiac glycogen and low lactate dehydrogenase/citrate synthase ratios, indicating diminished anaerobic and elevated aerobic myocardial metabolism in these animals. There was no synergistic effect between dietary restriction and dietary fibre addition, since no differences were observed in markers of oxidative stress in the F and DR-F groups. Dietary fibre supplementation, rather than energy intake and dietary restriction, appears to be the main process retarding oxidative stress in cardiac tissue.Key words: dietary fibre, dietary restriction, cardiac tissue, oxidative stress.

scholarly journals Improved reproductive performance achieved in tropical dairy cows by dietary beta-carotene supplementation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soparak Khemarach ◽  
Saowaluck Yammuen-art ◽  
Veerasak Punyapornwithaya ◽  
Sutichai Nithithanasilp ◽  
Narongrit Jaipolsaen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heat Stress ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Proportional Hazards ◽  
Beta Carotene ◽  
Experimental Period ◽  
Control Treatment ◽  
Beneficial Effects ◽  
Humidity Index

AbstractDairy farming in tropical climates is challenging as heat stress can impair reproduction in cows. Previous studies have demonstrated the beneficial effects of beta-carotene supplementation on bovine reproductive performance. This study was performed in Thailand, where the temperature-humidity index (THI) during the experimental periods was measured to range from 78.4 to 86.1. Lactating Holstein cows classified as repeat breeders (previous artificial insemination [AI] failures) were randomly assigned into two treatments, control treatment (T1; received placebo, n = 200) and test treatment (T2; received 400 mg/h/day of beta-carotene, n = 200). All cows were subjected to a protocol for synchronization of ovulation and timed artificial insemination (TAI). The day of the 1st ovulation synchronized protocol was defined as day 0, and the total experimental period was 160 days. Daily placebo or beta-carotene supplements were given orally on day 0 and each subsequent day of the experiment. Diagnosis of pregnancy was performed using ultrasound on day 30 after insemination. Non-pregnant cows were subjected to further ovulation synchronizations (maximum of four) and TAI over a period of 160 days. Milk samples were collected every ten days throughout the experiment. The samples were analyzed for beta-carotene concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. The pregnancies per AI of the cows in T2 were significantly greater than that of T1 from the 2nd to 4th TAI. During the entire experimental period, the pregnancies in T2 were significantly greater than that of T1. Cox's proportional hazards regression model data indicated a 44% greater probability of pregnancy for cows receiving beta-carotene. The concentrations of milk beta-carotene in T2 were significantly greater than T1 from the 2nd to 4th TAI. Significantly greater SOD and GPx activities were observed in T2 than T1, suggesting a reduction of oxidative stress in cows treated with beta-carotene. Dietary supplementation with beta-carotene thus improves the reproductive performance of repeat breeders exposed to heat stress, possibly by reducing oxidative stress.

scholarly journals EXPRESSION OF APELIN IS RELATED TO OXIDATIVE DAMAGE IN HEART TISSUE OF RATS DURING CHRONIC SYSTEMIC HYPOXIA

2019 ◽  
Vol 1 (2) ◽  
pp. 68-75
Author(s):  
H R Helmi ◽  
Frans Ferdinal ◽  
Ani Retno Prijanti ◽  
Sri Widia A Jusman ◽  
Frans D Suyatna
Keyword(s):  
Oxidative Stress ◽  
Cardiac Tissue ◽  
Heart Tissue ◽  
Male Rats ◽  
Heart Weight ◽  
Control Group ◽  
Sprague Dawley ◽  
Relative Expression ◽  
Beneficial Effects ◽  
Systemic Hypoxia

Background: Chronic systemic hypoxia is severe environmental stress for the heart and might lead to the development of heart failure. Apelin is an endogenous peptide that has been shown to have various beneficial effects on cardiac function. Apelin appears to have a role to play in the ventricular dysfunction and maintaining the performance of the heart.Objectives: In the present study we want to investigate the adaptive response of heart tissue to chronic systemic hypoxia and the correlation with apelin expression and oxidative stress in rat. Methods: An experimental study was performed using 28 Sprague-Dawley male rats, 8 weeks of age. Rats were divided into 7 groups 4 each, namely control group; normoxia (O2 atmosphere) and the treatment group of hypoxia (8% O2) for 6 hours; 1;3;5;7 and 14 days respectively. Body weight and heart weight were measured at each treatment. Ventricular thickness was measured by caliper, Apelin mRNA was measured using real-time qRT-PCR with Livak formula and malondialdehyde (MDA) level was used to assess oxidative stress due to cardiac tissue hypoxia.Results: Macroscopic exams showed hypertrophy at day 7th. The relative expression of Apelin mRNA in hypoxic heart is decreased at the beginning and then increased, starting from day-7 to day-14. The MDA levels were significantly increased from day-7 and were strongly correlated with relative expression Apelin.Conclusion:  It is concluded that the increase of Apelin expression is related to oxidative stress in heart tissue of rats during chronic systemic hypoxia.

Therapeutic hypercapnia prevents chronic hypoxia-induced pulmonary hypertension in the newborn rat

2006 ◽  
Vol 291 (5) ◽  
pp. L912-L922 ◽  
Author(s):  
Crystal Kantores ◽  
Patrick J. McNamara ◽  
Lilian Teixeira ◽  
Doreen Engelberts ◽  
Prashanth Murthy ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Vascular Remodeling ◽  
Chronic Hypoxia ◽  
Antioxidant Properties ◽  
Ventricular Performance ◽  
Pulmonary Vascular Remodeling ◽  
Beneficial Effects ◽  
Arterial Resistance ◽  
Pulmonary Arterial

Induction of hypercapnia by breathing high concentrations of carbon dioxide (CO2) may have beneficial effects on the pulmonary circulation. We tested the hypothesis that exposure to CO2 would protect against chronic pulmonary hypertension in newborn rats. Atmospheric CO2 was maintained at <0.5% (normocapnia), 5.5%, or 10% during exposure from birth for 14 days to normoxia (21% O2) or moderate hypoxia (13% O2). Pulmonary vascular and hemodynamic abnormalities in animals exposed to chronic hypoxia included increased pulmonary arterial resistance, right ventricular hypertrophy and dysfunction, medial thickening of pulmonary resistance arteries, and distal arterial muscularization. Exposure to 10% CO2 (but not to 5.5% CO2) significantly attenuated pulmonary vascular remodeling and increased pulmonary arterial resistance in hypoxia-exposed animals ( P < 0.05), whereas both concentrations of CO2 normalized right ventricular performance. Exposure to 10% CO2 attenuated increased oxidant stress induced by hypoxia, as quantified by 8-isoprostane content in the lung, and prevented upregulation of endothelin-1, a critical mediator of pulmonary vascular remodeling. We conclude that hypercapnic acidosis has beneficial effects on pulmonary hypertension and vascular remodeling induced by chronic hypoxia, which we speculate derives from antioxidant properties of CO2 on the lung and consequent modulating effects on the endothelin pathway.

C-type natriuretic peptide expression and pulmonary vasodilation in hypoxia-adapted rats

1998 ◽  
Vol 275 (4) ◽  
pp. L645-L652 ◽  
Author(s):  
James R. Klinger ◽  
Farjaad M. Siddiq ◽  
Richard A. Swift ◽  
Cynthia Jackson ◽  
Linda Pietras ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricle ◽  
Natriuretic Peptide ◽  
Right Atrium ◽  
Chronic Hypoxia ◽  
Right Atrial ◽  
Mrna Levels ◽  
Hypoxic Pulmonary Hypertension ◽  
Pulmonary Arterial ◽  
The Right

Atrial and brain natriuretic peptides (ANP and BNP, respectively) are potent pulmonary vasodilators that are upregulated in hypoxia-adapted rats and may protect against hypoxic pulmonary hypertension. To test the hypothesis that C-type natriuretic peptide (CNP) also modulates pulmonary vascular responses to hypoxia, we compared the vasodilator effect of CNP with that of ANP on pulmonary arterial rings, thoracic aortic rings, and isolated perfused lungs obtained from normoxic and hypoxia-adapted rats. We also measured CNP and ANP levels in heart, lung, brain, and plasma in normoxic and hypoxia-adapted rats. Steady-state CNP mRNA levels were quantified in the same organs by relative RT-PCR. CNP was a less potent vasodilator than ANP in preconstricted thoracic aortic and pulmonary arterial rings and in isolated lungs from normoxic and hypoxia-adapted rats. Chronic hypoxia increased plasma CNP (15 ± 2 vs. 6 ± 1 pg/ml; P < 0.05) and decreased CNP in the right atrium (35 ± 14 vs. 65 ± 17 pg/mg protein; P < 0.05) and in the lung (3 ± 1 vs. 14 ± 3 pg/mg protein; P < 0.05) but had no effect on CNP in brain or right ventricle. Chronic hypoxia increased ANP levels fivefold in the right ventricle (49 ± 5 vs. 11 ± 2 pg/mg protein; P < 0.05) but had no effect on ANP in lung or brain. There was a trend toward decreased ANP levels in the right atrium (2,009 ± 323 vs. 2,934 ± 397 pg/mg protein; P = not significant). No differences in CNP transcript levels were observed between the two groups of rats except that the right atrial CNP mRNA levels were lower in hypoxia-adapted rats. We conclude that CNP is a less potent pulmonary vasodilator than ANP in normoxic and hypoxia-adapted rats and that hypoxia raises circulating CNP levels without increasing cardiopulmonary CNP expression. These findings suggest that CNP may be less important than ANP or BNP in protecting against hypoxic pulmonary hypertension in rats.

The monocrotaline model of pulmonary hypertension in perspective

2012 ◽  
Vol 302 (4) ◽  
pp. L363-L369 ◽  
Author(s):  
Jose G. Gomez-Arroyo ◽  
Laszlo Farkas ◽  
Aysar A. Alhussaini ◽  
Daniela Farkas ◽  
Donatas Kraskauskas ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arterial Hypertension ◽  
Animal Models ◽  
Right Ventricle ◽  
Vascular Remodeling ◽  
Therapeutic Strategies ◽  
Relevant Model ◽  
Right Ventricle Dysfunction ◽  
Ventricular Afterload ◽  
Pulmonary Arterial

Severe forms of pulmonary arterial hypertension (PAH) are characterized by various degrees of remodeling of the pulmonary arterial vessels, which increases the pulmonary vascular resistance and right ventricular afterload, thus contributing to the development of right ventricle dysfunction and failure. Recent years have seen advances in the understanding of the pathobiology of PAH; however, many important questions remain unanswered. Elucidating the pathobiology of PAH continues to be critical to design new effective therapeutic strategies, and appropriate animal models of PAH are necessary to achieve the task. Although the monocrotaline rat model of PAH has contributed to a better understanding of vascular remodeling in pulmonary hypertension, we question the validity of this model as a preclinically relevant model of severe plexogenic PAH. Here we review pertinent publications that either have been forgotten or ignored, and we reexamine the monocrotaline model in the context of human forms of PAH.

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