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Perrin David - - 2004
In order to determine the influence of long-term prenatal hypoxia on the maturation of the brain catecholaminergic structures involved in motor and cognitive functions, pregnant rats were subjected to hypoxia (10% O2) from the 5th to 20th day of gestation. The in vivo activity of tyrosine hydroxylase (TH), the rate-limiting ...
Shin Bo Hee - - 2004
Previous studies have demonstrated that thiamine (vitamin B1) has a cytoprotective effect against ischemic damage to the heart, and that heat shock protein 70 (Hsp70) is capable of protecting cardiac cells from lethal ischemia/hypoxia. We show here that thiamine has a cytoprotective effect on cultured neonatal rat cardiomyocytes under hypoxic ...
Govindaraju Vasanthi - - 2005
The aim of this study was to determine whether increased expression of heme oxygenase (HO) contributes to impairment of aortic contractile responses after hypoxia through effects on reactivity to endothelin-1 (ET-1). Thoracic aortas from normoxic rats and rats exposed to hypoxia (10% O2) for 16 or 48 h were mounted ...
Marczak M - - 2004
In the present study we investigated whether hypocapnia that accompanies hypoxic hyperventilation might affect the biphasic, stimulatory/depressant, ventilatory response to hypoxia. The experiments were carried out in anesthetized, vagotomized, spontaneously breathing, and poikilocapnic rats. The animals were subjected to acute steady-state hypoxia consisting of 12% O(2) in N(2) in inspiratory ...
Nucci Tatiane B - - 2004
Nucleus raphe magnus (NRM) is one of the cellular groups of the brainstem that is involved in the physiologic responses to hypoxia and contains nitric oxide (NO) synthase. In the present study, we assessed the role of NO pathway in the NRM on the hypoxic ventilatory response (HVR) and anapyrexia ...
Portengen L - - 2004
BACKGROUND AND OBJECTIVES: We have previously reported that high rat urinary allergen (RUA) exposure was not associated with increased risk of rat allergy in long-term-exposed laboratory animal (LA) workers. We aimed to assess whether strong allergen-specific IgG4 responses could explain the absence of a dose response in these subjects. We ...
LaManna Joseph C - - 2004
Chronic exposure to a hypoxic environment leads to structural and functional adaptations in the rat brain. One significant adaptation is a decrease in intercapillary distances through a near doubling of the capillary density, which begins after about 1 week of hypoxic exposure and is completed by 3 weeks. Hypoxic angiogenesis ...
Olfert I Mark - - 2004
We characterized O2 consumption (VO2) during treadmill exercise in 12-, 24-, and 35-month-old Fischer 344 x Brown Norway F1 hybrid (F344BNF1) rats. When accounting for differences in body mass (Mb), (O2)peak decreased by 10% and 33% in 24- and 35-month-old rats, respectively, compared with rats at 12 months (analysis of ...
Kryzhanovskaya S Yu - - 2004
Somatometric indexes were modified in the offspring of rats exposed to hypobaric hypoxia. DNA synthesis and tissue mitotic index increased in 5-day-old male rats, but underwent less pronounced changes in females. Our results indicate that hypoxia modulates morphogenesis of the myocardium. We revealed sex differences in the reaction of newborn ...
Sanotskaya N V - - 2004
Effects of acute hypoxia on hemodynamics and respiration were studied in acute experiments on narcotized rats. The animals were divided into groups characterized by high, low-, and medium- resistance to hypoxia by the time of respiration arrest during inhalation of gas mixture containing 3% O2. Hemodynamic parameters of highly resistant ...
Schlenker Evelyn H - - 2004
We hypothesized that, in male rats, 10% fructose in drinking water would depress ventilatory responsiveness to acute hypoxia (10% O2 in N2) and hypercapnia (5% CO2 in O2) that would be depressed further by exposure to intermittent hypoxia. Minute ventilation (Ve) in air and in response to acute hypoxia and ...
Zhao Hong-Bo - - 2004
The effect of polysaccharide extract isolated from Ganoderma lucidum (Gl-PS) on rat cortical neuronal cultures exposed to hypoxia/reoxygenation (H/R) was studied in vitro. Gl-PS (1, 10, 100 microg/ml) increased neuron viability following H/R as measured by the inhibition of MTT reduction. Gl-PS also significantly reduced malondialdehyde content and reactive oxygen ...
Doan V D - - 2004
We tested the hypothesis that estradiol modifies respiratory control in pregnant rats and participates in the development of respiratory chemoreflexes in fetuses. Pregnant rats (n = 12) received daily subcutaneous injections of vehicle (Veh, n = 6) or 4-androsten-4-ol-3,17-dione acetate (ATD; inhibitor of estradiol synthesis; n = 6; 5 mg/day ...
Shefer T V - - 2004
Krebs cycle intermediates normalized gas exchange and decreased the mortality rate in rats with barbiturate coma. Treatment with other substrates including glucose and products of glycolysis was ineffective. Oxygen inhalation had no effect on oxygen consumption and indexes of external respiration. Our results suggest that deficiency of endogenous intermediates of ...
Lai Yih-Loong - - 2004
A close relationship exists between hypoxia-inducible factor (HIF)-1alpha and pulmonary hypertension. The present study was carried out to explore if there are temporal alterations in HIF-1alpha levels during prolonged hypoxia and after monocrotaline (MCT) treatment. First, young Wistar rats were divided into 5 groups: control, hypoxia-1, hypoxia-2, hypoxia-3 and hypoxia-4. ...
Bavis R W - - 2004
Neonatal hypoxia alters the development of the hypoxic ventilatory response in rats and other mammals. Here we demonstrate that neonatal hypoxia impairs the hypoxic ventilatory response in adult male, but not adult female, rats. Rats were raised in 10% O(2) for the first postnatal week, beginning within 12 h after ...
Dubovický M - - 2004
Intrauterine hypoxia associated with oxidative stress represents an important risk factor for development of neurobehavioral dysfunctions. In the present study, we investigated the potential protective effect of melatonin (MEL) on neurobehavioral dysfunctions induced by chronic intrauterine hypoxia in rats by the anticonvulsant drug phenytoin (PHT), which is known by its ...
Li Guohu - - 2004
Fetal programming has profound effects on cardiovascular function in later adult life. We tested the hypothesis that chronic hypoxic exposure during fetal development downregulates endogenous cardioprotective mechanisms in adult rats. Time-dated pregnant rats were divided between normoxic and hypoxic (10.5% O2 from days 15 to 21 of gestation) groups. The ...
Maresová D - - 2004
Exposition to the acute intensive hypobaric hypoxia blocks the triggering mechanism of epileptic seizures only within a short time interval after the end of hypoxia period and it does not influence the progressive epileptogenesis in 12-day-old rats. In 25-day-old rats' hypobaric hypoxia suppresses the postictal depression elicited by the repeated ...
Blackwell Sean C - - 2004
We determined the effect of an acute episode of severe hypoxia on peripheral nucleated red blood cell (RBC) counts in the fetal rat. Timed pregnant rats were randomized to a 2-hour exposure to hypoxia (placement in a chamber containing a gas mixture with 9% O2 +3% CO2 + balanced N2) ...
Ilyinsky Oleg - - 2003
In anesthetized rats, increases in phrenic nerve amplitude and frequency during brief periods of hypoxia are followed by a reduction in phrenic nerve burst frequency [posthypoxia frequency decline (PHFD)]. We investigated the effects of chronic exposure to hypoxia on PHFD and on peripheral and central O2-sensing mechanisms. In Inactin-anesthetized (100 ...
Uemura Koichi - - 2003
Carbon monoxide (CO) is the most popular cause of poisoning. The bilateral basal ganglia lesion characterizes the delayed neuronal cell death (DCD). We demonstrated there were both apoptosis and necrosis in the cortex, basal ganglia and hippocampus in a case of human CO accident. To elucidate the mechanism of DCD ...
Copple Bryan L - - 2004
Monocrotaline (MCT) is a pyrrolizidine alkaloid (PA) plant toxin that produces sinusoidal endothelial cell (SEC) injury, hemorrhage, fibrin deposition, and coagulative hepatic parenchymal cell (HPC) oncosis in centrilobular regions of rat livers. Cells with apoptotic morphology have been observed in the livers of animals exposed to other PAs. Whether apoptosis ...
Chen Chau-Fong - - 2003
Renal ischaemia releases reactive oxygen species (ROS) in the kidneys. We hypothesized that the kidneys are more resistant to the insult of ROS in chronically hypoxic rats. We thus compared rats kept at sea level (SL) and those that had been adapted to hypoxia (hypoxia adapted, HA) by exposure to ...
McColm Janet R - - 2004
The aim of this study was to investigate whether the mean around which arterial oxygen fluctuations take place was important in a unique animal model of oxygen-induced retinopathy. Retinopathy of prematurity (ROP) is associated with fluctuating arterial oxygen. A recent retrospective study suggested that management of high-risk preterm infants at ...
Eynan Mirit - - 2003
BACKGROUND: Several studies have been conducted in recent years in the attempt to improve running performance by the use of hyperbaric oxygen, but there is disagreement as to whether this has any beneficial effect. The purpose of this study was to measure the effect of 24 h breathing 100% O2 ...
Zabka A G - - 2003
Age and the estrus cycle affect time-dependent respiratory responses to episodic hypoxia in female rats. Respiratory long-term facilitation (LTF) is enhanced in middle-aged vs. young female rats (72). We tested the hypothesis that phrenic and hypoglossal (XII) LTF are diminished in acyclic geriatric rats when fluctuating sex hormone levels no ...
Zhang Wei - - 2003
PURPOSE: To test the hypothesis that in an experimental model of retinopathy of prematurity (ROP) rat pups that are at risk for but do not have retinal neovascularization (NV) exhibit a normal oxygenation response to a hyperoxic inhalation challenge. METHODS: Newborn Sprague-Dawley rats were raised under two varied oxygen conditions ...
Shimono Hiroo - - 2003
Using precision-cut liver slices (20-25 mg wet weight) from male Wistar rats, we examined whether clinically relevant propofol concentrations have hepatoprotective or -toxic effects during hypoxia/reoxygenation. Slices were preincubated for 2 h in sealed roller vials (three slices per vial) containing Waymouth's medium (37 degrees C; 95% oxygen/5% CO(2)). Then, ...
Raff Hershel - - 2003
Hypoxia is well known to decrease appetite and weight gain in growing rats, and to induce weight loss in humans. It has been hypothesized that this is mediated by a change in ghrelin, an orexigenic peptide synthesized and released primarily from the stomach. Rats were exposed to hypoxia for 7 ...
Shirai Mikiyasu - - 2003
1. Chronic hypoxia (CH) increases lung tissue expression of all types of nitric oxide synthase (NOS) in the rat. However, it remains unknown whether CH-induced changes in functional and histological NOS distributions are correlated in rat small pulmonary arteries. 2. We measured the effects of NOS inhibitors on the internal ...
Zhang Wei - - 2003
PURPOSE: To test the hypothesis that retinal hypoxia is present during vascular development in normal rat pups and in a newborn rat model of retinopathy of prematurity (ROP). METHODS: Preretinal vitreous PO(2) measurements were made during room air breathing using (19)F magnetic resonance spectroscopy (MRS) and a perfluoro-15-crown-5-ether droplet in ...
Ouyang Ping - - 2003
OBJECTIVE: To investigate the effects of flavone extracted from the leaves of Diospyros kaki on the apoptosis of rat cardiac myocytes induced by hypoxia-reoxygenation and advanced glycation end products in vitro. METHODS: The cardiac myocytes were isolated from neonatal SD rats and cultured in vitro for 72 h. Apoptosis of ...
Van Genechten Jeroen - - 2004
The Fawn-Hooded rat (FHR), a model for primary pulmonary hypertension, shows an unexplained hypersensitivity to airway hypoxia. Because pulmonary neuroepithelial bodies (NEBs) appear to express a functional oxygen-sensing mechanism and an extensive sensory innervation, possible changes in this system should be taken into consideration. In the present study a comparative ...
Lai James C K - - 2003
The immature brain is more resistant to hypoxia/ischemia than the mature brain. Although chronic hypoxia can induce adaptive-changes on the developing brain, the mechanisms underlying such adaptive changes are poorly understood. To further elucidate some of the adaptive changes during postnatal hypoxia, we determined the activities of four enzymes of ...
Sumin M N - - 2003
Experiments on rats showed that changes in the hemoglobin profile during hypoxia are determined by switching of erythropoiesis from the "basic" to "emergency" mode. The "basic" mode of erythropoiesis is typical of the mature organism under normal conditions. The "reserve" or "emergency" mode is realized in fetuses, senile animals, and ...
Motoyama Satoru - - 2003
OBJECTIVE: To investigate the mechanism by which methylprednisolone protects the liver from hypoxia-induced injury. DESIGN: Prospective control study using the isolated rat liver. SETTING: Animal research facility. SUBJECTS: Male, fasted, pathogen-free Sprague-Dawley rats. INTERVENTIONS: Low-flow hypoxia was produced by reducing afferent perfusate pressure from 10 to 2.5 cm H(2)O; isolated ...
Van Genechten Jeroen - - 2003
The Fawn-Hooded rat (FHR) strain reveals a congenital predisposition to primary (idiopathic) pulmonary hypertension (PPH), and can therefore be regarded as an animal model in which to study possible mechanisms underlying an inherited susceptibility to pulmonary hypertension. Pulmonary hypertension can be induced in FHRs after a short exposure to mild ...
Huerkamp Michael J - - 2003
Greater than 30% mortality was observed unexpectedly in rat pups of weaning age kept with their dams in individually ventilated cages (IVC). A subsequent controlled study involving an induced electrical power failure that halted ventilation of IVC containing rat dams and pups showed that oxygen concentrations in the air in ...
Daneshrad Z - - 2003
The effect of exposure to hypobaric hypoxia for 4 weeks (oxygen pressure = 106 hPa), equivalent to 5500 m in altitude) on myocardial total lactate dehydrogenase (tLDH) activity and isoform (H and M) composition was comparatively studied in growing (4.5 weeks old) and in adult (4.5 months old) male rats. ...
Nadlewska Agnieszka - - 2003
We investigated the effects of D-AP7 [D-(-)-2-amino-7-phosphonoheptanoic acid], a specific, potent antagonist of NMDA receptor on certain forms of behavior in control groups of rats and in rats submitted to hypoxia. D-AP7 given intracerebroventrically (icv) at a dose of 5 nmol was tested in the open field test, passive avoidance ...
Miller O L - - 2003
Severe 3-h hypobaric hypoxia was followed by impairment of Ca(2+)-mediated glutamatergic signal transduction in the posthypoxic period (no less than 72 h). This impairment manifested in changes in the calcium response to glutamate application in slices of rat brain cortex. Moderate hypoxic preconditioning prevented these disturbances developed over the first ...
Dreshaj Ismail A - - 2003
We sought to examine the role of the basomedial hypothalamus in the regulation of breathing in neonatal rats. Small basomedial hypothalamic lesions were produced by a lesioning agent, goldthioglucose, in 5-d-old male rat pups, and 2 d later, baseline ventilation and the ventilatory responses to hypoxia and hypercapnia were examined. ...
Hynie S - - 2003
This study investigates changes of adenylyl cyclase activity in the heart of young and adult Wistar rats exposed to experimental conditions simulating high altitude hypoxia as a model for interpretation of some adaptive changes of adenylyl cyclase observed in human. The exposure of rats to intermittent high altitude (IHA) hypoxia ...
Stvolinskii S L - - 2003
Natural hydrophilic antioxidant carnosine protects cerebral cytosolic Cu,Zn-superoxide dismutase (SOD) under conditions of oxidative stress in various in vivo models: short-term hypobaric hypoxia in rats and accumulation of age-related changes in senescence-accelerated mice (SAMP). Administration of carnosine preventing Cu,Zn-SOD inactivation reduced mortality in rats and prolonged average life span in ...
Melin Alexandre - - 2003
The aims of this study were to relate heart morphology and functions changes to heart rate variability (HRV) components after acclimatization to high altitude and to define whether preadaptation to hypoxia could modulate HRV responses to acute hypoxic stress. Doppler-echocardiographic studies of the left ventricle were performed in female Wistar ...
Melin Alexandre - - 2002
Although chronic exposure to high altitude or carbon monoxide (CO) induces several cardiovascular adaptations in mammals, very little information is available on the cardiovascular effects due to exposure to these concomitant stresses. In particular, cardiac functional responses to chronic CO inhalation at high altitude has never been investigated. Thirty-two male ...
Cheng Deyun - - 2002
OBJECTIVE: To investigate the role of adrenomedullin (AM) in the development of hypoxic pulmonary hypertension (HPH), and to assess the expression of AM and adrenomedullin receptor (AMR) in the lungs of rats with HPH. METHODS: We exposed 10 rats to normobaric hypoxic conditions for 3 weeks to establish rat model ...
Zhu Xiaoping - - 2003
Nitric oxide (NO) is essential for optimal myofilament function of the rat diaphragm in vitro during active shortening. Little is known about the role of NO in muscle contraction under hypoxic conditions. Hypoxia might increase the NO synthase (NOS) activity within the rat diaphragm. We hypothesized that NO plays a ...
Chen Guang-Di - - 2002
Chemical asphyxiants have been shown to potentiate noise-induced hearing loss (NIHL) in our previous reports. However, it is still unclear whether hypoxia interacts with noise to potentiate NIHL. This is an important issue, since many people at risk of exposure to noise may also suffer from hypoxia. In the present ...
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