Search Results
Results 351 - 400 of 675
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Mimura Y - - 1995
The objective of this study was to investigate renal phosphate excretion during 24 h of hypoxia in conscious rats fed by total parenteral nutrition. Wistar rats weighing 190 g were exposed to hypoxia (inspired oxygen fraction = 0.10) or normoxia (inspired oxygen fraction = 0.21) for 24 h in a ...
Ma Y L - - 1995
The effects of removal of endogenous corticosteroids via bilateral adrenalectomy in combination with noise exposure (30 min at 100 dB) were determined by recording compound action potential (CAP) and endocochlear potentials (EP), and by measuring potassium concentrations (K+e) within the endolymph. Thirty-eight Long-Evans rats were divided into groups according to ...
Teng G Q - - 1995
Responses to hypoxia of lung arteries (200-350 microns) from control (C) and chronically hypoxic (CH) rats were compared in a myograph before and after blockade of NO synthase with NG-nitro-L-arginine methyl ester (L-NAME). After precontraction with prostaglandin F2 alpha (PGF2 alpha), hypoxia caused a four-phase tension change: brief dilation, transient ...
Reynaud X - - 1995
PURPOSE: To study electroretinographic responses of infant rats with a history of exposure to high-ambient oxygen. METHODS: Electroretinographic responses to a range of full-field stimuli were recorded from 13-day-old (n = 8) and 18-day-old (n = 10) rats with a history of intermittent exposure to 80% oxygen and age-matched controls. ...
King A P - - 1995
A group of rats was born in and spent the first 4 weeks of life at a simulated altitude of 3550 m. Two animals were killed immediately afterwards and the remaining 16 were allowed to recover for various times up to a maximum of 12 weeks at sea-level atmospheric pressure. ...
Torbati D - - 1995
We examined the modifying effects of CO2 on the CNS and pulmonary manifestations of hyperbaric oxygenation (HBO) in newborn rats. Four- to seven-day-old rats were exposed to HBO with inspired PCO2 (PICO2) of approximately 0, 60, 90, 140, 190, and 380 mmHg at a total pressure of 5 atm abs. ...
Turner D A - - 1995
We have evaluated the effects of hypoxia on changes in light transmittance (delta T/T) in rat hippocampal interface slices at 36 degrees C, using a digital imaging system. Slice translucence increased only slightly (delta T/T = 4.65% in CA1; control 2.27%) during brief hypoxia in which hypoxic spreading depression-like depolarization ...
Yamamoto H - - 1995
We recently identified and characterized a protease present in rat serum which is capable of generating des(1-3)IGF-I. In this study, we have investigated the effects of GH deficiency and replacement on the activity of this protease in rat serum and tissue extracts. Protease activity was significantly higher in sera from ...
Petit R D - - 1995
We previously found that augmentation of polycythemia by exogenous human recombinant erythropoietin (EPO) failed to worsen the severity of hypoxic pulmonary hypertension in rats. We asked whether this unexpected finding was related to reductions in cardiac output, left ventricular end-diastolic pressure, pulmonary vascular resistance, or some combination of these factors. ...
Frappell P - - 1995
In resting euthermic mammals, hypoxia elicits a hyperventilation that results from a combination of hyperpnea and hypometabolism. Often accompanying the hypoxia-induced hypometabolism is a drop in body temperature. To separate the synergic effects of hypothermia per se from the direct effects of hypoxia on metabolic rate, ventilation (VE), and O2 ...
Colice G L - - 1995
The pathogenesis of high-altitude pulmonary edema (HAPE) is not well understood. Ventilation and fluid-handling abnormalities at high altitude (HA) may play a role in HAPE. Because ventilatory and cardiopulmonary responses to chronic HA exposure in the Hilltop (H) strain of Sprague-Dawley rat are different from those in the Madison (M) ...
Carregal M - - 1995
During hypoxia the isolated rat atria released lactate into the bathing medium and underwent a rise of resting tension and a decline of the peak developed tension and pacemaker frequency. The atria from 24 h fasted rats, which oxidize faster their endogenous triacylglycerol pool, showed greater functional disturbances during hypoxia ...
Thomas A J - - 1995
Apneic patterns in breathing can be classically conditioned in rats by brief neonatal exposures to hypoxia, noise, and petting during sleep (A. J. Thomas, W. Austin, L. Friedman, and K. P. Strohl, J. Appl. Physiol. 73: 1530-1536, 1992); thus animals may acquire apneic patterns by exposure to not only respiratory ...
Torbati D - - 1995
Retinopathy of prematurity (ROP) usually occurs after a prolonged exposure to normobaric hyperoxia in newborn mammals and infants. We hypothesized that experimental ROP also could develop after acute exposures to hyperbaric oxygenation (HBO), providing that a severe and maintained retinal vasoconstriction occurred during HBO exposure. Five- to seven-day-old, Long Evans ...
Perides G - - 1995
Possible neuroprotective actions of osteogenic protein-1 (OP-1) were evaluated in a rat model of cerebral hypoxia/ischemia. Intraperitoneal injection of 50 micrograms of OP-1 prior to bilateral carotid ligation and transient hypoxia in 12-day-old rats reduced cerebral infarct area from 44.8 +/- 3.3% in vehicle-injected controls to 29 +/- 4.9%. Treatment ...
Herget J - - 1995
Mechanical properties of the adult pulmonary vasculature are affected by perinatal experience of hypoxic pulmonary hypertension. In the present study, we followed the long-term effects of perinatal pulmonary hypertension induced by means other than hypoxia in rats. Daily injections of indomethacin (1 mg.kg-1 body weight (BW)) were given to the ...
Wyatt C N - - 1995
Carotid body-mediated ventilatory increases in response to acute hypoxia are attenuated in animals reared in an hypoxic environment. Normally, O2-sensitive K+ channels in neurosecretory type I carotid body cells are intimately involved in excitation of the intact organ by hypoxia. We have therefore studied K+ channels and their sensitivity to ...
Matsuoka T - - 1995
We asked whether hypoxia and hypercapnia, singly or combined, affect the lung volume-dependent ventilatory inhibition [Hering-Breuer (HB) reflex] in newborn rats. Conscious rats 2, 5, and 8 days old were breathing in a flow plethysmograph. Mean lung volume was increased by applying a negative body surface pressure of 6 or ...
Sohmer H - - 1995
The human fetus responds to sound stimuli while still in utero. The rat and cat begin to hear only after birth. Therefore neonatal rat and cat are used as models of the development of auditory sensitivity in the human fetus. The inner ear of rat responds to stimuli delivered directly ...
Emery C J - - 1995
The pulmonary vasodilator action of an S-nitrosothiol, S-nitroso acetylpenicillamine (SNAP), was investigated in the rat pulmonary vasculature. The influence of its nitric oxide donator property was studied by comparison with the effect of acetylpenicillamine (AP), SNAP minus the nitroso group, and the blockade of nitric oxide release by the L-arginine ...
Arieli R - - 1995
Our purpose is to develop a survival strategy for man trapped in a confined space. We used immature pigs to assess the applicability of findings in rats for a larger mammal. The pig consumed oxygen in a sealed chamber until hypoxic collapse. We measured blood pressure, oxygen consumption, inspired O2 ...
Chen C F - - 1995
The effect of aprotinin, a nonspecific kallikrein inhibitor on renal function was studied in chronic hypoxic rats (high altitude, HA), comparing to control rats kept at sea level (SL). Hypoxia was induced by placing female Wistar rats (195-230 g) in an altitude chamber (5,500 m) 15 hr per day for ...
Herget J - - 1995
Adult rats born in hypoxia but raised in air are more reactive to acute hypoxic challenges. The relation between perfusion pressure and perfusion flow (P/Q plot) was analyzed in the preparation of ventilated perfused lungs isolated from 3 groups of adult rats. Control animals of the first group were born ...
Wiester M J - - 1995
Studies in both humans and rats have indicated that certain pulmonary responses induced by exposure to an acute provocative concentration of ozone (O3) will eventually attenuate if the exposure is repeated on a daily basis. This phenomenon is commonly referred to as O3 adaptation. Whether or not a "state" of ...
Xue C - - 1994
Expression and localization of nitric oxide synthase (NOS) in the lungs of chronically hypoxic and normoxic rats were studied using both immunohistochemistry and NADPH diaphorase (NADPH-d) staining techniques. In the normoxic and in the hypoxic rat, NOS was detected by both methods in the endothelium of large pulmonary vessels and ...
Frappell P B - - 1994
The postnatal developments of the rat and hamster were compared after the animals were raised from birth for 21 days either in normoxia (control animals) or chronic hypoxia (PO2 of 80-90 Torr). Compared with control rats, hypoxic rats had a reduction in body mass. Hypoxic rats had lowered O2 consumption ...
White L D - - 1994
Fos protein, the product of the immediate early gene c-fos, has been used as a metabolic marker to map the O2 chemosensory pathway activated by hypoxia in the adult rat (Erickson and Millhorn, Brain Res. 567: 11-24, 1991). The current study provides evidence that the O2 chemoreceptor pathway develops during ...
Yagi A - - 1994
The present study was undertaken to elucidate the effects of sodium tanshinone VI 1-phenolate (1), 1'-O-hydrogen succinyltanshinone VI 1-O-hydrogen succinate (2), and disodium 1'-O-succinyltanshinone VI 1-O-succinate (3), water-soluble derivatives of tanshinone VI, on post-hypoxic contractile recovery of isolated perfused rat hearts. The effects were compared with those of tanshinone VI ...
Arieli R - - 1994
Cumulative O2 toxicity (K) can be calculated using the expression K = t2 x PO2c, where t is exposure time and the power c is to be determined; the phenomenon is liable to occur when K reaches Kc, the threshold value of K at which a symptom is manifested. Six ...
Le Couteur D G - - 1994
During liver transplantation, donor livers are subject to hypoxia and reoxygenation. Recently, because of a shortage of suitable donors, the livers of older donors have been used for transplantation. In this study, we examined the influence of aging and nutritional state on hepatic intracellualr pH (pHi) and the susceptibility of ...
Clark J M - - 1994
Tolerance to 100% O2 or to O2 with 60 torr PICO2 (O2-CO2) was determined at pressures of 1.0-4.0 atm abs in normal rats and in rats adapted to combined hypoxia and hypercapnia (HHA) before O2 or O2-CO2 exposure. Results were compared with previous studies of tolerance to O2 or O2-CO2 ...
Gonzalez N C - - 1994
The effect of hematocrit (Hct) on O2 transport in hypoxic [inspired PO2 (PIO2) approximately 70 Torr] and normoxic (PIO2 approximately 145 Torr) exercise was studied in rats acclimatized to 3 wk of PIO2 at approximately 70 Torr (A rats) and in nonacclimatized littermates (NA rats). Isovolumic exchange transfusion of plasma ...
Fantini E - - 1994
This study was undertaken to evaluate the direct cardioprotective effect of trimetazidine (TMZ), an anti-anginal drug devoid of haemodynamic action, on isolated myocytes. Cultured rat ventricular myocytes were treated with the drug 16 h and 1 h before the experiments. The drug-treated cells and control cells were placed in a ...
Harik S I - - 1994
Prolonged hypoxia causes several adaptive changes in systemic physiology and tissue metabolism. We studied the effects of hypobaric hypoxia on glucose transport at the blood-brain barrier (BBB) in the rat. We found that hypoxia increased the density of brain microvessels seen on immunocytochemical stains using an antibody to the glucose ...
Le Couteur D G - - 1994
During liver transplantation, oxidative stress occurs during hypoxia and reoxygenation of the donor organ. Chemical oxidative stress impairs cell membrane transport. Therefore, in this study the influence of hypoxia and reoxygenation on hepatocellular membrane transport was investigated. Specifically, glucose transport was studied in the perfused rat liver using the multiple ...
Beall H D - - 1994
The metabolisms of two standard electron acceptors and a series of bioreductive antitumor compounds by purified rat and human DT-diaphorases (DTD) were compared. DTD was purified from rat liver cytosol and from Escherichia coli in which rat liver or human lung tumor DTD complementary DNA was expressed. Km and kcat ...
Russell P C - - 1994
Histamine constricts postcapillary lung vessels and also causes dilatation, site unknown. In chronically hypoxic rats, pulmonary arterioles are muscularized and histamine-containing mast cells increase. We wanted to determine a) whether vasoreactivity to histamine changes in chronic hypoxia; b) whether dilatation is due to H2 receptors; and c) which vessels dilate. ...
Shimizu S - - 1994
In an attempt to assess the erythropoietin (Epo) production site(s) in rat kidney, Epo response to hypoxia and renal histopathological changes were studied in rats administered with graded doses of gentamicin. Male Sprague-Dawley rats of 9 to 11 weeks old were used. Following a 14-day subcutaneous administration (67.5 or 33.8 ...
Lin W Q - - 1994
Immunocytochemical studies have revealed that one of the major heat shock proteins, HSP72, is induced in livers of rats that have been pretreated with phenobarbital and then administered halothane in a hypoxic gas mixture of 10% oxygen. To determine the sub-cellular localization of HSP72 in the livers of these rats ...
Maskrey M - - 1994
Urethane-anaesthetised rats were exposed to hypoxia (7% O2 in N2) for 5 min periods while body core temperature (Tbc) was maintained within the normal range (37-38 degrees C) using an abdominal heat exchanger. Animals were exposed to hypoxia and after placement of electrolytic lesions in either the anterior (n = ...
Mimura Y - - 1994
This study evaluated the effect of acute hypoxia on renal handling of phosphate in rats in the presence and absence of parathyroid hormone (PTH). Hypoxia causes respiratory alkalosis in spontaneously breathing humans and animals. Respiratory alkalosis has been reported to induce a blunted phosphaturic response to PTH. In this study, ...
Resta T C - - 1994
Evidence suggests that nitric oxide synthesis within the pulmonary circulation may be attenuated during chronic hypoxia in Wistar rats due to reduced L-arginine availability. In contrast, chronically hypoxic Sprague-Dawley rats exhibit normal endothelium-dependent pulmonary vasodilation. The purpose of the present study was to determine whether 1) Wistar rats demonstrate greater ...
Chawla R K - - 1994
S-Adenosylmethionine (AdoMet) is an important biologic methylating agent for nucleic acids, phospholipids, biologic amines, and proteins. Previous studies indicated that hepatic AdoMet synthetase and hepatic levels of AdoMet are subnormal in patients with alcoholic cirrhosis. This abnormality limits the patients' capacity to convert phosphatidylethanolamine to phosphatidylcholine by way of phosphatidylethanolamine-N-methyltransferase ...
Heydeck D - - 1994
In this study, the effect of prenatal hypoxia on the catecholamine sensitivity of the offspring of pregnant rats was investigated. The offspring from hypoxic animals showed after treatment with isoproterenol in adult age a distinctly more pronounced decrease of protein content and enzyme activities in heart tissue as well as ...
Licciardi A - - 1994
The generations of rats raised in normobaric hypoxia (10% O2 in N2) were observed for changes in their oxygen-hemoglobin affinity, hemoglobin content (Hb) blood O2 capacity and pO2-O2 content curves: the first generation (H1) and the second generation (H2). H1 rats possessed a lower O2-Hb affinity while H2 rats had ...
Koudelová J - - 1994
The effect of normobaric oxygen atmosphere on hypoxia-enhanced lipid peroxidation in the brain cortex, subcortical structures, medulla oblongata and in the cerebellum was observed in 7- and 21-day-old and adult rats. The production of free oxygen radicals causing lipid peroxidation was assessed by the method described by Ohkawa et al. ...
Churchill T A - - 1994
The effects of cold hypoxia were examined during a time-course at 2 degrees C on levels of glycolytic metabolites: glycogen, glucose, glucose-1-phosphate, glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-bisphosphate, phosphoenolpyruvate, pyruvate, lactate and energetics (ATP, ADP, AMP) of livers from rats and columbian ground squirrels. Responses of adenylate pools reflected the energy imbalance created ...
Yang S L SL Department of Physiology, Graduate Institute of Medicine, Kaohsiung Medical College, Taiwan, - - 1994
Electroencephalography (EEG) was utilized for investigating the effect of hyperthermia followed by apneic hypoxia in rats. They were heated whole-bodily to 41 degrees C for 15 min under the control of an artificial rodent ventilator, after drug-induced generalized paralysis. A transcutaneous oxygen saturation monitor was applied to detect the hypoxic ...
Klein J - - 1993
Moderate hypoxia induced in rats by inhalation of 10% oxygen led to an increase of the concentration of free choline in the brain and caused a large net-release of choline from the brain into the venous blood as determined by the measurement of the arterio-venous difference. In hippocampal slices from ...
Mian R - - 1993
We have examined the surface ultrastructure and morphological characteristics of leucocytes obtained from control rats breathing air and rats made acutely hypoxic (breathing 6% O2, for 30 min). Striking ultrastructural and morphological changes occurred in the leucocytes of hypoxic rats. These changes included the appearance of crater-like holes, a reduction ...
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