effects of hyperoxia in body

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease among neonates, with increasing morbidity and mortality. This study aims to investigate the effect and mechanism of lysine demethylase 3A (KDM3A) on hyperoxia-induced BPD. Hyperoxia-induced BPD mouse and alveolar epithelial cell models were constructed. The effects of hyperoxia on lung development were evaluated by histological and morphological analysis. The levels of KDM3A, E26 transformation specific-1 (ETS1), H3 lysine 9 dimethylation (H3K9me2), and endoplasmic reticulum (ER) stress-related indexes were quantified by RT-qPCR, Western blot, and IF staining...

BACKGROUND: Pulmonary vasodilators, including oxygen, have not shown consistent beneficial effects on pulmonary hypertension due to valvular heart disease (PH-VHD). Therefore, the study aimed to assess the effect of 100% fractional inspiration of oxygen (FiO2 ) on pulmonary and systemic hemodynamics in patients with combined pre- and post-capillary pulmonary hypertension (CpcPH) and isolated post-capillary pulmonary hypertension (IpcPH) due to PH-VHD. METHODS: This prospective study was conducted among patients with PH-VHD undergoing mitral or aortic valve replacement or repair...

Oxygen level is a key regulator of organogenesis and its modification in postnatal life alters the maturation process of organs, including the intestine, which do not completely develop in utero. The β3-adrenoreceptor (β3-AR) is expressed in the colon and has an oxygen-dependent regulatory mechanism. This study shows the effects of the β3-AR agonist BRL37344 in a neonatal model of hyperoxia-driven colonic injury. For the first 14 days after birth, Sprague-Dawley rat pups were exposed to ambient oxygen levels (21%) or hyperoxia (85%) and treated daily with BRL37344 at 1, 3, 6 mg/kg or untreated...

Acute hyperbaric O2 (HBO) therapy after spinal cord injury (SCI) can reduce inflammation and increase neuronal survival. To our knowledge, it is unknown if these benefits of HBO require hyperbaric vs. normobaric hyperoxia. We used a C4 lateralized contusion SCI in adult male and female rats to test the hypothesis that the combination of hyperbaria and 100% O2 (i.e. HBO) more effectively mitigates spinal inflammation and neuronal loss, and enhances respiratory recovery, as compared to normobaric 100% O2 . Experimental groups included spinal intact, SCI no O2 therapy, and SCI + 100% O2 delivered at normobaric pressure (1 atmosphere, ATA), or at 2- or 3 ATA...

Oxygen deprivation and excess are both toxic. Thus, the body's ability to adapt to varying oxygen tensions is critical for survival. While the hypoxia transcriptional response has been well studied, the post-translational effects of oxygen have been underexplored. In this study, we systematically investigate protein turnover rates in mouse heart, lung, and brain under different inhaled oxygen tensions. We find that the lung proteome is the most responsive to varying oxygen tensions. In particular, several extracellular matrix (ECM) proteins are stabilized in the lung under both hypoxia and hyperoxia...

We tested the hypotheses that self-paced aerobic exercise performance is reduced following four hours of cold-water immersion when breathing air and further reduced when breathing 100% oxygen (O2). Nine healthy adults (four women; age 24 ± 3 years; body fat 17.9 ± 6.4%; VO2max 48±9 mL • kg • minute⁻¹) completed three visits: a no-immersion control trial and two experimental trials consisting of a four-hour cold-water immersion (20.1±0.3°C) either breathing air (FIO2 = 0...

BACKGROUND: Despite the possible clinical benefit of high intraoperative oxygen therapy on surgical site infection, the effect on postoperative respiratory function is debatable. However, it remains yet to be elucidated whether hyperoxia due to a high fraction of inspired oxygen used in conjunction with lung protective ventilation can lead to increased incidence of postoperative pulmonary complications. METHODS: In this noninferiority randomized trial, an intraoperative high fraction of inspired oxygen of 0...

Rationale: Although sleep apnea occurs in over 50% of individuals with Alzheimer's Disease (AD) or related tauopathies, little is known concerning the potential role of tauopathy in the pathogenesis of sleep apnea. Here, we tested the hypotheses that, during presumptive sleep, a murine model of tauopathy (rTg4510) exhibits: 1) increased breathing instability; 2) impaired chemoreflex function; and 3) exacerbation of these effects with tauopathy progression. Methods: rTg4510 mice initially develop robust tauopathy in the hippocampus and cortex, and eventually progresses to the brainstem...

Asphyxiated newborns often require both therapeutic hypothermia (TH) and mechanical ventilation (MV) and the complex interrelationship between these two therapeutic interventions is very interesting, which could not only have several synergistic positive effects but also some risks. Perinatal asphyxia is the leading cause of neonatal hypoxic-ischemic encephalopathy (HIE) and TH is the only approved neuroprotective treatment to limit brain injury, improving the mortality rate and long-term neurological outcomes...

BACKGROUND: Supplemental oxygen impairs lung development in newborn infants with respiratory distress. Lactobacillus johnsonii supplementation attenuates respiratory viral infection in mice and exhibits anti-inflammatory effects. This study investigated the protective effects of intranasal administration of L. johnsonii on lung development in hyperoxia-exposed neonatal mice. METHODS: Neonatal C57BL/6N mice were reared in either room air (RA) or hyperoxia condition (85% O2 )...

Individuals born preterm are at higher risk of cardiovascular and metabolic diseases in adulthood, through mechanisms not completely understood. White adipose tissue in humans and rodents is a dynamic endocrine organ and a critical player in the regulation of metabolic homeostasis. However, the impact of preterm birth on white adipose tissue remains unknown. Using a well-established rodent model of preterm birth-related conditions in which newborn rats are exposed during postnatal days 3-10 to 80% of oxygen, we evaluated the impact of transient neonatal hyperoxia on adult perirenal white adipose tissue (pWAT) and liver...

RATIONALE: Xylazine has emerged in recent years as an adulterant in an increasing number of opioid-positive overdose deaths in the United States. Although its exact role in opioid-induced overdose deaths is largely unknown, xylazine is known to depress vital functions and cause hypotension, bradycardia, hypothermia, and respiratory depression. OBJECTIVES: In this study, we examined the brain-specific hypothermic and hypoxic effects of xylazine and its mixtures with fentanyl and heroin in freely moving rats...

The lifetime growth of almost all fishes follows a biphasic relationship - juvenile growth is rapid and adult growth subsequently decelerates. For a trend that is so ubiquitous, there is no general agreement as to the underlying mechanisms causing adult growth to decelerate. Ongoing theories argue that adult growth slows because either the gills fail to supply the body with surplus oxygen needed for continued somatic gain (i.e. oxygen limited), or because sexual maturation induces a switch in energy allocation towards reproduction and away from growth (i...

Transient receptor potential ankyrin 1 (TRPA1), a member of the TRP superfamily of cation channels, is broadly expressed in sensory neural pathways, including the trigeminal neurons innervating the nasal cavity and vagal neurons innervating the trachea and the lung. TRPA1 acts as a detector of various irritant chemicals as well as hypoxia and hyperoxia. For the past 15 years, we have characterised its role in respiratory and behavioural modulation in vivo using Trpa1 knockout (KO) mice and wild-type (WT) littermates...

Glutamine (Gln) is the most widely acting and abundant amino acid in the body and has anti-inflammatory properties, regulates body metabolism, and improves immune function. However, the mechanism of Gln's effect on hyperoxic lung injury in neonatal rats is unclear. Therefore, this work focused on examining Gln's function in lung injury of newborn rats mediated by hyperoxia and the underlying mechanism. We examined body mass and ratio of wet-to-dry lung tissue weights of neonatal rats. Hematoxylin and eosin (HE) staining was performed to examine histopathological alterations of lung tissues...

BACKGROUND: Extensive animal investigation informed clinical practice regarding the harmful effects of high fractional inspired oxygen concentrations (FiO2 s > 0.60). Since questions persist whether lower but still supraphysiologic FiO2  ≤ 0.60 and > 0.21 (FiO2  ≤ 0.60/ > 0.21) are also harmful with inflammatory lung injury in patients, we performed a systematic review examining this question in animal models...

BACKGROUND: Supraphysiologic oxygen administration causes unfavorable clinical outcomes in various diseases, including traumatic brain injury, post-cardiac arrest syndrome, and acute lung injury. Accidental hypothermia is a critical illness that reduces oxygen demands, and excessive oxygen is likely to emerge. This study aimed to determine whether hyperoxia would be associated with increased mortality in patients with accidental hypothermia. METHODS: A post-hoc analysis of a nationwide multicenter prospective observational study (ICE-CRASH study) on patients with accidental hypothermia admitted in 2019-2022 was conducted...

BACKGROUND: Prone position ventilation (PPV) has been recommended for patients with acute respiratory distress syndrome (ARDS) to improve oxygenation. However, whether prolonged prone ventilation will aggravate hyperoxia and whether abdominal compression will aggravate permissive hypercapnia acidosis are topics of concern. We carried out a retrospective analysis to investigate the issues above. METHODS: Clinical data were collected from 97 moderate-to-severe ARDS patients who received PPV as part of their treatment in the intensive care unit (ICU) of the First Affiliated Hospital of Guangzhou Medical University from November 2015 to May 2021...

Background and Objectives : The use of closed-circuit rebreathers (CCRs) in recreational diving is gaining interest. However, data regarding its physiological effects are still scarce. Immersion, cold water, hyperoxia, exercise or the equipment itself could challenge the cardiopulmonary system. The purpose of this study was to examine the impact of CCR diving on lung function and autonomous cardiac activity after a series of CCR dives in cold water. Materials and Methods : Eight CCR divers performed a diving trip (one week) in the Baltic Sea...

Adjunctive therapy for hypertension is in high demand for clinical research. Therefore, several meta-analyses have provided sufficient evidence for meditation as an adjunct therapy, without being anchored on reliable physiological grounds. Meditation modulates the autonomic nervous system. Herein, we propose a hierarchical-dependent effect for the carotid body (CB) in attenuating blood pressure (BP) and ventilatory variability (VV) fine-tuning due to known nerve connections between the CB, prefrontal brain, hypothalamus, and solitary tract nucleus...