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Hawrysh PJ, Myrka AM, Buck LT. Review: A history and perspective of mitochondria in the context of anoxia tolerance. Comp Biochem Physiol B Biochem Mol Biol 2022; 260:110733. [PMID: 35288242 DOI: 10.1016/j.cbpb.2022.110733] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 01/01/2023]
Abstract
Symbiosis is found throughout nature, but perhaps nowhere is it more fundamental than mitochondria in all eukaryotes. Since mitochondria were discovered and mechanisms of oxygen reduction characterized, an understanding gradually emerged that these organelles were involved not just in the combustion of oxygen, but also in the sensing of oxygen. While multiple hypotheses exist to explain the mitochondrial involvement in oxygen sensing, key elements are developing that include potassium channels and reactive oxygen species. To understand how mitochondria contribute to oxygen sensing, it is informative to study a model system which is naturally adapted to survive extended periods without oxygen. Amongst air-breathing vertebrates, the most highly adapted are western painted turtles (Chrysemys picta bellii), which overwinter in ice-covered and anoxic water bodies. Through research of this animal, it was postulated that metabolic rate depression is key to anoxic survival and that mitochondrial regulation is a key aspect. When faced with anoxia, excitatory neurotransmitter receptors in turtle brain are inhibited through mitochondrial calcium release, termed "channel arrest". Simultaneously, inhibitory GABAergic signalling contributes to the "synaptic arrest" of excitatory action potential firing through a pathway dependent on mitochondrial depression of ROS generation. While many pathways are implicated in mitochondrial oxygen sensing in turtles, such as those of adenosine, ATP turnover, and gaseous transmitters, an apparent point of intersection is the mitochondria. In this review we will explore how an organelle that was critical for organismal complexity in an oxygenated world has also become a potentially important oxygen sensor.
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Affiliation(s)
- Peter John Hawrysh
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Alexander Morley Myrka
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Leslie Thomas Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
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Cigarette Smoke Extract Produces Superoxide in Aqueous Media by Reacting with Bicarbonate. TOXICS 2021; 9:toxics9110316. [PMID: 34822707 PMCID: PMC8622692 DOI: 10.3390/toxics9110316] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/01/2021] [Accepted: 11/19/2021] [Indexed: 12/17/2022]
Abstract
The toxicity of cigarette smoke (CS) is largely attributed to its ability to generate reactive oxygen species (ROS). Reportedly, CS generates superoxide in cell culture systems by stimulating the cells to produce superoxide and through direct chemical reactions with components of the culture media. In this study, we investigated CS-induced superoxide formation in biocompatible aqueous media and its characteristics. Cigarette smoke extract (CSE) and total particulate matter (TPM) were prepared from the mainstream smoke of 3R4F reference cigarettes. CSE and TPM generated superoxide in Hank’s balanced salt solution (HBSS), Dulbecco’s modified Eagle media (DMEM), and blood plasma, but not in distilled water and phosphate-buffered saline. Each constituent of HBSS in solution was tested, and bicarbonate was found to be responsible for the superoxide generation. More than half of the superoxide formation was abolished by pretreating CSE or TPM with peroxidase, indicating that the substrates of peroxidase, presumably peroxides and peroxy acids, mainly contributed to the superoxide production. In conclusion, the presence of bicarbonate in experimental conditions should be considered carefully in studies of the biological activity of CS. Furthermore, the local amount of bicarbonate in exposed tissues may be a determinant of tissue sensitivity to oxidative damage by CS.
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Almeida MR, Horta JGÁ, de Matos NA, de Souza ABF, Castro TDF, Cândido LDS, Andrade MC, Cangussú SD, Costa GDP, Talvani A, Bezerra FS. The effects of different ventilatory modes in female adult rats submitted to mechanical ventilation. Respir Physiol Neurobiol 2020; 284:103583. [PMID: 33202295 DOI: 10.1016/j.resp.2020.103583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 10/30/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022]
Abstract
This study aimed to analyze the effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) modes in female Wistar rats. 18 Wistar female adult rats were divided into three groups: control (CG), pressure-controlled ventilation (PCVG), and volume-controlled ventilation (VCVG). PCVG and VCVG were submitted to MV for one hour with a tidal volume (TV) of 8 mL/Kg, respiratory rate of 80 breaths/min, and positive end-expiratory pressure of 0 cmH2O. At the end of the experiment, all animals were euthanized. The neutrophils and lymphocytes influx to lung were higher in VCVG and PCVG compared to CG. The activities of superoxide dismutase, catalase and myeloperoxidase were higher in PCVG compared to CG. There was an increase in lipid peroxidation and protein oxidation in PCVG compared to CG. The levels of CCL3 and CCL5 were higher in PCVG compared to CG. In conclusions, the PCV mode promoted structural changes in the lung parenchyma, redox imbalance and inflammation in healthy adult female rats submitted to MV.
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Affiliation(s)
- Matheus Rocha Almeida
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Jacques Gabriel Álvares Horta
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil; Department of Clinical Medicine/Pediatrics, School of Medicine, Federal University of Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Natália Alves de Matos
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Ana Beatriz Farias de Souza
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Thalles de Freitas Castro
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Leandro da Silva Cândido
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Mônica Campos Andrade
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Sílvia Dantas Cangussú
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Guilherme de Paula Costa
- Laboratory of Immunobiology of Inflammation (LABIIN), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - André Talvani
- Laboratory of Immunobiology of Inflammation (LABIIN), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil
| | - Frank Silva Bezerra
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Brazil.
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Steiner AR, Rousseau-Blass F, Schroeter A, Hartnack S, Bettschart-Wolfensberger R. Systematic Review: Anaesthetic Protocols and Management as Confounders in Rodent Blood Oxygen Level Dependent Functional Magnetic Resonance Imaging (BOLD fMRI)-Part A: Effects of Changes in Physiological Parameters. Front Neurosci 2020; 14:577119. [PMID: 33192261 PMCID: PMC7646331 DOI: 10.3389/fnins.2020.577119] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 09/10/2020] [Indexed: 12/09/2022] Open
Abstract
Background: To understand brain function in health and disease, functional magnetic resonance imaging (fMRI) is widely used in rodent models. Because animals need to be immobilised for image acquisition, fMRI is commonly performed under anaesthesia. The choice of anaesthetic protocols and may affect fMRI readouts, either directly or via changing physiological balance, and thereby threaten the scientific validity of fMRI in rodents. Methods: The present study systematically reviewed the literature investigating the influence of different anaesthesia regimes and changes in physiological parameters as confounders of blood oxygen level dependent (BOLD) fMRI in rats and mice. Four databases were searched, studies selected according to pre-defined criteria, and risk of bias assessed for each study. Results are reported in two separate articles; this part of the review focuses on effects of changes in physiological parameters. Results: A total of 121 publications was included, of which 49 addressed effects of changes in physiological parameters. Risk of bias was high in all included studies. Blood oxygenation [arterial partial pressure of oxygen (paO2)], ventilation [arterial partial pressure of carbon dioxide (paCO2)] and arterial blood pressure affected BOLD fMRI readouts across various experimental paradigms. Conclusions: Blood oxygenation, ventilation and arterial blood pressure should be monitored and maintained at stable physiological levels throughout experiments. Appropriate anaesthetic management and monitoring are crucial to obtain scientifically valid, reproducible results from fMRI studies in rodent models.
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Affiliation(s)
- Aline R. Steiner
- Section of Anaesthesiology, Department of Clinical and Diagnostic Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Frédérik Rousseau-Blass
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Aileen Schroeter
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Sonja Hartnack
- Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Regula Bettschart-Wolfensberger
- Section of Anaesthesiology, Department of Clinical and Diagnostic Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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Extended recording of LMA in rats: Effects of IV catheters, "comfort jackets" and chamber lids on arterial blood gas parameters. J Pharmacol Toxicol Methods 2019; 99:106594. [PMID: 31158458 DOI: 10.1016/j.vascn.2019.106594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/24/2019] [Accepted: 05/28/2019] [Indexed: 11/22/2022]
Abstract
The standard infrared photobeam locomotor activity system has been used extensively in neurobiology and neuropharmacology to study the functional impact of direct manipulations of the nervous system. There is interest in using the activity monitors to assess the early stages of drug withdrawal in rodents. In a standard twice-daily dosing strategy animals would be dosed at 6:00 am and 5:00 pm for 15 to 30 days. There is interest in using the chambers to assess the early stages of the discontinuation syndrome. Placement of the rodents into the chambers following the scheduled sham or vehicle last dose of a 15- to 30-day subchronic dosing regimen (b.i.d., t.i.d., etc.) and monitoring overnight allows for a quantitative measure of the initial physiological homeostatic acclimation period during the lights-out period. By using the chambers there is no circadian dysrhythmia induced as an experimental confound and objectively verifiable data is generated during the period expected to correspond with the plasma drug levels approaching zero and the onset of discontinuation syndrome. We demonstrated that untreated "normal" rats showed a normal decelerating time-effect curve over the 12-hour monitoring period that was not compromised by restricted access to food and water. Arterial blood gas monitoring before and after 12 h of night-time activity chamber monitoring clearly demonstrated normal respiratory function with no clinical signs of any blood gas-based diagnosis of metabolic dysfunction.
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Svorc P, Petrasova D, Svorc Jr P. Chronobiological study of sex differences in the internal environment in zoletil-anaesthetized rats. BIOL RHYTHM RES 2019. [DOI: 10.1080/09291016.2018.1564577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Pavol Svorc
- Department of Physiology, Medical Faculty Safarik’s University, Kosice, Slovak Republic
- Department of Physiology and Pathophysiology, Medical Faculty, Ostrava University, Ostrava, Czech Republic
| | - Darina Petrasova
- Laboratory of Research Bio-models, Medical Faculty Safarik’s University, Kosice, Slovak Republic
| | - Pavol Svorc Jr
- Department of Physiology and Pathophysiology, Medical Faculty, Ostrava University, Ostrava, Czech Republic
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SVORC P, PETRÁŠOVÁ D, SVORC P. Arterial pH and Blood Gas Values in Rats Under Three Types of General Anesthesia: a Chronobiological Study. Physiol Res 2018; 67:721-728. [DOI: 10.33549/physiolres.933692] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The aim of study was to review the status of arterial pH, pO2 and pCO2 under general anesthesias in dependence on the light-dark (LD) cycle in spontaneously breathing rats. The experiments were performed using three- to four-month-old pentobarbital(P)-, ketamine/xylazine(K/X)- and zoletil(Z)-anesthetized female Wistar rats after a four-week adaptation to an LD cycle (12 h light:12 h dark). The animals were divided into three experimental groups according to the anesthetic agent used: P (light n=11; dark n=8); K/X (light n=13; dark n=11); and Z (light n=18; dark n=26). pH and blood gases from arterial blood were analyzed. In P anesthesia, LD differences in pH, pO2, and pCO2 were eliminated. In K/X anesthesia, parameters showed significant LD differences. In Z anesthesia, LD differences were detected for pH and pO2 only. Acidosis, hypoxia, and hypercapnia have been reported for all types of anesthesia during the light period. In the dark period, except for P anesthesia, the environment was more stable and values fluctuated within normal ranges. From a chronobiological perspective, P anesthesia was not the most appropriate type of anesthesia in these rat experiments. It eliminated LD differences, and also produced a more acidic environment and more pronounced hypercapnia than K/X and Z anesthesias.
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Affiliation(s)
- P. SVORC
- Department of Physiology, Medical Faculty Safarik’s University, Kosice, Slovak Republic
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Qi H, Mariager CØ, Lindhardt J, Nielsen PM, Stødkilde‐Jørgensen H, Laustsen C. Effects of anesthesia on renal function and metabolism in rats assessed by hyperpolarized
MRI. Magn Reson Med 2018. [DOI: 10.1002/mrm.27165] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Haiyun Qi
- MR Research Centre, Department of Clinical MedicineAarhus UniversityAarhus Denmark
| | | | - Jakob Lindhardt
- MR Research Centre, Department of Clinical MedicineAarhus UniversityAarhus Denmark
| | - Per Mose Nielsen
- MR Research Centre, Department of Clinical MedicineAarhus UniversityAarhus Denmark
| | | | - Christoffer Laustsen
- MR Research Centre, Department of Clinical MedicineAarhus UniversityAarhus Denmark
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Skott M, Nørregaard R, Birke-Sørensen H, Palmfeldt J, Kwon TH, Jonassen T, Frøkiær J, Nielsen S. Development of intestinal ischemia/reperfusion-induced acute kidney injury in rats with or without chronic kidney disease: Cytokine/chemokine response and effect of α-melanocyte-stimulating hormone. Kidney Res Clin Pract 2014; 33:79-88. [PMID: 26877955 PMCID: PMC4714152 DOI: 10.1016/j.krcp.2014.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 02/04/2014] [Accepted: 02/10/2014] [Indexed: 01/11/2023] Open
Abstract
Background The primary aim of the study was to investigate the cytokine/chemokine response in the kidney, lung, and liver following acute kidney injury (AKI). The secondary aim was to test whether α-melanocyte-stimulating hormone (α-MSH) could prevent a reduction in organ function, and attenuate the inflammatory cytokine/chemokine response within the kidney, lung, and liver following AKI in rats with or without preexisting chronic kidney disease (CKD). Methods A two-stage animal model, in which AKI was induced in rats with preexisting CKD, induced by 5/6 nephrectomy (Nx), was used. Six weeks later, AKI was induced by intestinal ischemia and reperfusion (IIR). Sham procedures [S(Nx) and S(IIR)] were also performed. Results Increasing levels of serum creatinine (sCr) demonstrated progressive development of CKD in response to Nx, and following IIR sCr levels increased further significantly, except in the S(Nx) group treated with α-MSH. However, no significant differences in the fractional increase in sCr were observed between any of the groups exposed to IIR. In kidney, lung, and liver tissue the levels of interleukin (IL)-1β were significantly higher in rats undergoing IIR when compared to the S(IIR) and control rats. The same pattern was observed for the chemokine monocyte chemoattractant protein (MCP)-1 in lung and liver tissue. Furthermore, kidney IL-1β and RANTES levels were significantly increased after IIR in the Nx rats compared to the S(Nx) rats. Conclusion Both the functional parameters and the cytokine/chemokine response are as dramatic when AKI is superimposed onto CKD as onto non-CKD. No convincing protective effect of α-MSH was detected.
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Affiliation(s)
- Martin Skott
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark; The Water and Salt Research Center, University of Aarhus, Aarhus, Denmark
| | - Rikke Nørregaard
- The Water and Salt Research Center, University of Aarhus, Aarhus, Denmark; Institute of Clinical Medicine, University of Aarhus, Aarhus, Denmark
| | | | - Johan Palmfeldt
- Research Unit for Molecular Medicine, Aarhus University Hospital, Skejby, Denmark
| | - Tae-Hwan Kwon
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Thomas Jonassen
- Department of Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen Frøkiær
- The Water and Salt Research Center, University of Aarhus, Aarhus, Denmark; Institute of Clinical Medicine, University of Aarhus, Aarhus, Denmark
| | - Søren Nielsen
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark; The Water and Salt Research Center, University of Aarhus, Aarhus, Denmark
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Subramanian RK, Sidharthan A, Maneksh D, Ramalingam L, Manickam AS, Kanthakumar P, Subramani S. Normative data for arterial blood gas and electrolytes in anesthetized rats. Indian J Pharmacol 2013; 45:103-4. [PMID: 23543943 PMCID: PMC3608284 DOI: 10.4103/0253-7613.106451] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Kania RE, Herman P, Tran Ba Huy P, Ar A. Role of nitrogen in transmucosal gas exchange rate in the rat middle ear. J Appl Physiol (1985) 2006; 101:1281-7. [PMID: 16840582 DOI: 10.1152/japplphysiol.00113.2006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigates the role of nitrogen (N2) in transmucosal gas exchange of the middle ear (ME). We used an experimental rat model to measure gas volume variations in the ME cavity at constant pressure. We disturbed the steady-state gas composition with either air or N2 to measure resulting changes in volume at ambient pressure. Changes in gas volume over time could be characterized by three phases: a primary transient increase with time (phase I), followed by a linear decrease (phase II), and then a gradual decrease (phase III). The mean slope of phase II was −0.128 μl/min (SD 0.023) in the air group ( n = 10) and −0.105 μl/min (SD 0.032) in the N2 group ( n = 10), but the difference was not significant ( P = 0.13), which suggests that the rate of gas loss can be attributed mainly to the same steady-state partial pressure gradient of N2 reached in this phase. Furthermore, a mathematical model was developed analyzing the transmucosal N2 exchange in phase II. The model takes gas diffusion into account, predicting that, in the absence of change in mucosal blood flow rate, gas volume in the ME should show a linear decrease with time after steady-state conditions and gas composition are established. In accordance with the experimental results, the mathematical model also suggested that transmucosal gas absorption of the rat ME during steady-state conditions is governed mainly by diffusive N2 exchange between the ME gas and its mucosal blood circulation.
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Affiliation(s)
- Romain E Kania
- Service d'Oto-Rhino-Laryngologie et de Chirurgie de la Face et du Cou, Hôpital Lariboisière, 2, rue Ambroise Paré, 75010 Paris, France.
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12
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Bettin D, Gross C, Hertting K, Exner J, Honig A. Different cardiorespiratory responses to hemorrhage and hyperoxia in normotensive (WKY) and spontaneously hypertensive (SHR) rats. ACTA PHYSIOLOGICA HUNGARICA 2004; 91:23-48. [PMID: 15334829 DOI: 10.1556/aphysiol.91.2004.1.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To compare the cardiorespiratory responses underlying the beneficial effects of hyperoxia during blood loss between normotensive (WKY) and hypertensive (SHR) rats. METHODS Experiments were carried out in anesthetized animals with both carotid bifurcations either innervated or denervated. The effects of breathing 60% O2 in N2 were studied either in combination with non-hypotensive hemorrhage or during hemorrhagic hypotension. RESULTS In normoxia arterial pressure fell more in SHR than in WKY for a given blood loss. During hyperoxia, nerve-intact rats showed initial suppression of ventilation, but bifurcation-denervated rats a powerful enhancement. In all groups, hyperoxia increased the overall tone of venous capacitance vessels. CONCLUSIONS The greater blood loss in SHR than in WKY when bleeding down to a given arterial pressure results from a stronger constriction of venous capacitance vessels. Hyperoxia improves the ability of the cardiorespiratory system to resist the effects of hemorrhage by increasing the overall venous tone, thus supporting cardiac filling, and in some cases also by increasing alveolar ventilation, probably secondary to improved cerebral oxygenation. The beneficial effects of hyperoxia were: (i) not prevented by carotid denervation, and thus were presumably direct tissue effects of oxygen, (ii) strikingly weaker in SHR than in normotensive (WKY) rats.
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Affiliation(s)
- D Bettin
- Institute of Physiology of the Ernst-Moritz-Arndt-University of Greifswald, Greifswald, Germany.
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Bäckman T, Larmas MA. Chronic metabolic alkalosis, sucrose diet and dentine formation in young rats. Arch Oral Biol 1997; 42:299-304. [PMID: 9222449 DOI: 10.1016/s0003-9969(97)00011-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
As acid-base status has an effect on bone formation and remodelling, chronic metabolic alkalosis was induced in 3-week-old rats for 6 and 7 weeks with 0.25 mol/1 of NaHCO3 in their drinking water to determine whether it has any effect on dentinogenesis in the molars. One group of rats was fed a high-sucrose diet and the other two a standard diet. The control groups had the same diets but drank distilled water. All the rats were injected with tetracycline to mark the onset of dentine apposition. The alkalotic effect of the NaHCO3 drinking water was confirmed by blood gas analysis at the end of the experiment. After death, tetracycline-marked dentine apposition was measured from sagittally sectioned mandibular molars. Chronic metabolic alkalosis did not affect dentine apposition in the groups with the high-sucrose diet, nor in the groups with the standard diet at 6 weeks, but reduced it significantly in first and second molars in 7 weeks at rats on the standard diet. A high-sucrose diet alone caused a greater reduction in the amount of dentine. The general growth of the rats was not affected in any of the groups.
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Affiliation(s)
- T Bäckman
- Department of Preventive Dentistry and Cariology, University of Oulu, Finland
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14
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Alfaro V, Peinado VI, Palacios L. Factors influencing acid-base status during acute severe hypothermia in unanesthetized rats. RESPIRATION PHYSIOLOGY 1995; 100:139-49. [PMID: 7624615 DOI: 10.1016/0034-5687(95)00126-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Blood acid-base changes were studied during acute hypothermia (4-6 h) induced by cold exposure in the unanesthetized rat. Stewart's quantitative analysis was applied as a complementary approach to determine the relative contributions of several non-respiratory components to the arterial acid-base response. Acute decrease in body temperature (TB) lowered PaCO2 (32.5 to 14.5 mmHg) and [HCO3-]a(24.20 mEq/L to 17.56 mEq/L), increased pHa (7.481 to 7.608) and diminished the [OH-]/[H+] ratio, but had no significant effect on [SID] or [Atot], although both total phosphorus [PT] and inorganic phosphate [Pi] increased. The acid-base changes found were intermediate between those predicted by alpha-stat and pH-stat hypotheses. Deviation from the regulative alpha-imidazole strategy was more apparent in the plasma than in the intraerythrocyte compartment. We conclude that blood pH changes observed were mainly caused by increased relative ventilation (lung ventilation per unit of CO2 removed) and by resulting changes in PCO2, with a minor metabolic component but without significant contribution from ionic shifts or changes in plasma protein concentration.
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Affiliation(s)
- V Alfaro
- Departamento de Bioquímica y Fisiología, Universidad de Barcelona, Spain
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15
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Gaudy JH, Sicard JF, Maneglia R, Quignon M. [The effect of halothane on blood gases and arterial acid-base equilibrium in intact rats and in chemo-denervated rats]. Can J Anaesth 1993; 40:883-90. [PMID: 8403185 DOI: 10.1007/bf03009263] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Halothane decreases the ventilatory response to hypoxia and the activity of peripheral arterial chemoreceptors, resulting in "chemical chemodenervation." In order to evaluate the role of this halothane-induced "chemical denervation" in acid-base and arterial blood gas changes, these values were measured in intact and chemodenervated rats, awake and under anaesthesia. Since the depth of anaesthesia could be modified by the anatomical chemodenervation, the ED50 of inspired halothane was determined in six rats before and after anatomical chemodenervation. To prevent haemodynamic changes due to halothane and/or anatomical chemodenervation from interfering with the results, systemic arterial blood pressure and heart rate were measured in six intact rats, awake and then anaesthetized, and in the same rats after chemodenervation, awake and then anaesthetized. In nine intact rats and in 19 chemodenervated rats, arterial pH, arterial bicarbonate concentration, and arterial blood gases (PaO2 and PaCO2) were measured before and after administration of halothane. Anatomical chemodenervation modified neither the inspired ED50 (1.1%), nor the mean arterial blood pressure or heart rate. The haemodynamic effects of halothane were comparable in intact and in chemodenervated rats. Changes in arterial blood gases and acid-base balance due to halothane in intact rats and due to chemodenervation in awake rats were not different, but there was a decrease in PaO2 and pHa, and an increase in PaCO2. In chemodenervated rats, halothane caused a further decrease in PaO2 and a further increase in PaCO2. The fact that halothane and anatomical chemodenervation have similar effects on arterial blood gases and acid-base balance favours a "chemical chemodenervating" action of halothane. However, the additional effects of halothane in the anatomically chemodenervated animal show that the action of halothane on blood gases and acid-base balance is the result of multiple sites of impact on the respiratory system.
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Affiliation(s)
- J H Gaudy
- Laboratoire d'Anesthésiologie, Faculté de Médecine Saint-Antoine, Paris, France
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16
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Alfaro V, Palacios L. Comparison of acid/base status in conscious and anaesthetized rats during acute hypothermia. Pflugers Arch 1993; 424:416-22. [PMID: 8255725 DOI: 10.1007/bf00374903] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Acute hypothermia was surface-induced in unrestrained conscious rats at two different levels, moderate (30 degrees C TB) and severe (20 degrees C TB). Data reflecting the acid/base status were determined. The values obtained for moderate hypothermia were compared with the acid/base pattern observed during hypothermia induced by two different anaesthetics, sodium pentobarbital and urethane, at room temperature. Conscious, hypothermic animals developed an apparent respiratory alkalosis, with an increase in pHa (from 7.476 to 7.546 in moderate hypothermia and from 7.484 to 7.563 in severe hypothermia) correlated with a decrease in arterial bicarbonate levels (from 22.9 to 16.8 mmol l-1 and from 20.7 to 14.9 mmol l-1 respectively). Lactate increased slightly in conscious, severely hypothermic rats (1.02 mmol l-1). This acid/base pattern was clearly different from that seen in sodium pentobarbital (mild respiratory acidosis) and urethane-induced hypothermia (metabolic acidosis). These results suggest that conscious rats follow a pattern closer to that underlying the relative alkalinity shown by many poikilotherms than to that underlying the constant pH shown in hibernating mammals. This latter pattern, nevertheless, approaches that observed during moderate pentobarbital hypothermia and the acid/base pattern during shallow hypothermia in birds. Anaesthesia may interfere with the development of the processes that lead to the acid/base pattern observed in conscious animals.
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Affiliation(s)
- V Alfaro
- Departamento de Bioquímica y Fisiología, Facultad de Biología, Universidad de Barcelona, Spain
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17
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Gaudy JH, Sicard JF, Quignon M. [The measurement of pH and gases in the blood using microanalysis: the effect of storage at 4 degrees C for an hour. A study in the rat]. Can J Anaesth 1992; 39:786-90. [PMID: 1288903 DOI: 10.1007/bf03008289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The effects of one hour storage at 4 degrees C on micro blood gas samples (150 microliters) were studied for a wide range of values (pH: 7.11-7.58; PCO2: 26-97 mmHg; PO2: 31-503 mmHg) in 20 rats with indwelling carotid artery catheters. Blood gas values were modified by varying the composition of inspired gases: normoxia, hypocapnic hypoxia, hyperoxia, hypercapnia (in this case eight animals were anaesthetized with halothane 1.1%). One hundred and eight double micro-samples were taken. For each double sample, one was analysed immediately (H0) and compared with the second sample after one hr storage at 4 degrees C (H1). The Bland and Altman method was used for the statistical analysis of results. After one hr storage at 4 degrees C, the PCO2 was slightly higher than at H0 (mean difference +/- SD: +1.08 +/- 1.7 mmHg) and arterial pH was slightly lower (mean difference +/- SD: -0.016 upH +/- 0.011 upH). These results show that for these two variables, in the range studied, one hour storage at 4 degrees C had little effect. In contrast, for arterial PO2 the mean difference between all measurements between H1 and H0 was -17 +/- 25 mmHg. If results lower than 200 mmHg (56 double samples) are considered separately, the mean difference between values at H1 and H0 was only -0.98 +/- 5.3 mmHg. For PaO2 greater than 200 mmHg (52 double samples), the mean difference was -34 +/- 26.3 mmHg; this may be due to low reproducibility of measurements of elevated PO2 levels and to the effects of cellular metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J H Gaudy
- Laboratoire d'Anesthésiologie, Faculté de médecine Saint-Antoine, Paris, France
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18
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Alfaro V, Palacios L. Differential effects of hypothermia upon blood acid-base state and blood gases in sodium pentobarbital and urethane anaesthetised rats. GENERAL PHARMACOLOGY 1992; 23:677-82. [PMID: 1397974 DOI: 10.1016/0306-3623(92)90147-c] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
1. The effects of two anaesthetics, sodium pentobarbital and urethane, and the effects of anaesthesia-associated hypothermia on acid-base status and blood gases were studied in rats without assisted ventilation. 2. Manipulation of conscious rats produces a progressive increase in arterial lactate associated with slight hyperventilation. 3. Sodium pentobarbital anaesthesia produces mild respiratory acidosis accompanied by increase in lactate arterial values. Urethane anaesthesia leads to partially compensated metabolic acidosis. 4. Hypothermia reduces metabolic acidosis and hypercapnia induced by sodium pentobarbital anaesthesia. No difference between hypothermic and normothermic values was observed in urethane anaesthesia.
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Affiliation(s)
- V Alfaro
- Departamento de Bioquímica y Fisiología, Facultad de Biología, Universidad de Barcelona, Spain
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19
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Khera KS. Chemically induced alterations in maternal homeostasis and histology of conceptus: their etiologic significance in rat fetal anomalies. TERATOLOGY 1991; 44:259-97. [PMID: 1948764 DOI: 10.1002/tera.1420440306] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Possible relationships between maternal acid-base-electrolyte imbalance, histological changes in the maternal/extraembryonic tissues (decidua, placenta, membranes enclosing cavities), and fetal anomalies induced by maternotoxic doses of ethylene glycol, sodium salicylate, and cadmium chloride in rats were investigated. Acid-base-electrolyte, histologic and, teratologic studies were conducted concurrently with, as far as feasible, a similar protocol. Ethylene glycol caused 1) maternal homeostatic changes including metabolic acidosis and hyperosmolality, 2) extraembryonic lesions with degeneration of allantois and reduced villigenesis being more prevalent, and 3) materno-fetal effects such as decreases in fetal and maternal body weights, decreased maternal food intake, and fetal abnormalities (vertebral, rib, and sternebral defects). Few of these changes occurred when NaHCO3, an endogenous agent known to correct metabolic acidosis, was coadministered with ethylene glycol. Ethylene glycol-induced maternal metabolic acidosis, concurrent with hyperosmolality, was suspected to contribute toward reduction in villigenesis and fetal anomalies, including body weight reductions. Sodium salicylate induced the following: 1) mild maternal acidosis, hypokalemia, and hypophosphatemia with no significant change in pH; 2) maternal hemorrhage in extraembryonic cavities, papillary proliferation of the visceral yolk sac endoderm, and failure to form the chorioallantoic labyrinth; and 3) resorptions, hydrocephaly, rib defects, and fetal body weight reduction. Upon simultaneous treatment with sodium salicylate, NaHCO3 significantly reduced, and NH4Cl enhanced the incidence of the above histologic and teratologic effects, without significantly altering acid-base values. An etiologic association between the above salicylate-induced maternal and extraembryonic lesions and teratogenicity was likely. Cadmium chloride, whether administered by the intraperitoneal (ip) or intravenous (iv) route, caused 1) hydrocephaly, anophthalmia, vertebral and rib defects, reduction in fetal body weight, resorptions and maternal toxicity (acute peritonitis by the ip route only), and 2) extensive necrosis and hemorrhage in the decidua basalis, hemorrhage in the ectoplacental cone and around Reichert's membrane, and absence of chorioallantoic labyrinth. An etiologic relationship between these teratologic and histologic effects seemed probable, since both were dose-related. From the above studies, it was hypothesized that maternal factors--metabolic acidosis, hyperosmolality, hemorrhages in the ectoplacental cone, extraembryonic cavities, and around Reichert's membrane, and necrosis of decidua basalis--may have, directly or indirectly, reduced fetal nutrition and materno-embryonic gaseous exchange, which ultimately altered fetal development.
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Affiliation(s)
- K S Khera
- Toxicology Research Division, Health and Welfare Canada, Ottawa, Ontario
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20
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Davies DG, McGrath JJ. Arterial blood gas status in rats exposed to chronic CO at low and high altitude. RESPIRATION PHYSIOLOGY 1989; 75:193-8. [PMID: 2496448 DOI: 10.1016/0034-5687(89)90063-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Arterial blood gases were measured in 52 unanesthetized Sprague-Dawley rats following six weeks exposure to either room air at ambient altitude (950 m), room air containing 100 ppm CO at ambient altitude, room air at 4575 m simulated high altitude, or room air containing 100 ppm CO at 4575 m simulated high altitude. PaCO2 was significantly higher in animals exposed to CO both at ambient altitude (38.2 vs 34.5 Torr) and simulated high altitude (28.3 vs 23.6 Torr). The data show that chronic exposure to low concentrations of CO depresses ventilatory drive at both ambient and simulated high altitude. This depression could be related to changes in brain blood flow and the acidity of the central medullary chemosensitive area or to changes in peripheral chemoreceptor activity.
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Affiliation(s)
- D G Davies
- Department of Physiology, Texas Tech University Health Sciences Center, Lubbock 79430
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21
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Nemery B. Respiratory and non-respiratory lung function indices during the development and resolution of O,S,S-trimethyl phosphorodithioate-induced lung damage in the rat. A chemical model of adult respiratory distress syndrome. J Appl Toxicol 1987; 7:391-6. [PMID: 3429765 DOI: 10.1002/jat.2550070608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Arterial blood gases and the pulmonary uptake of putrescine and 5-hydroxytryptamine (5-HT) were studied between 6 h and 18 days after the administration to rats of an oral LD50-dose of the pneumotoxin, O,S,S-trimethyl phophorodithioate (OSSMe), a potential impurity in several organophosphorus insecticides. Aortic blood was sampled under pentobarbitone anaesthesia for measurements of arterial pH, and partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2). PaO2 was significantly decreased 4 days after OSSMe administration, i.e. at the time of maximum lethality and increases in wet lung weight. This was accompanied by a significant increase in PaCO2 and acidosis. These results are compatible with an impairment of gas exchange due to diffuse lung damage. For reasons that are unclear, PaCO2 was slightly increased 2, 6 and 12 days after dosing. The uptake of putrescine (1,4-diaminobutane) and of 5-HT was measured by incubating lung slices with several concentrations of [3H]-putrescine and [14C]-5-HT, so as to estimate the apparent kinetic parameters of uptake, Vmax and Km. The Vmax for putrescine-uptake was significantly decreased 1, 2, 4, 6 and 12 days after the administration of OSSMe. The Vmax for 5-HT-uptake was significantly increased 1 day and significantly decreased 4 days after OSSMe administration. The uptake of 5-HT is an endothelial function, and the decrease in 5-HT-uptake at 4 days may reflect injury to the pulmonary vascular endothelium at this time. The uptake of putrescine probably reflects the function of the pulmonary (mainly alveolar) epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B Nemery
- Medical Research Council, Toxicology Unit, Carshalton, Surrey, U.K
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22
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Numao Y, Koshiya N, Gilbey MP, Spyer KM. Central respiratory drive-related activity in sympathetic nerves of the rat: the regional differences. Neurosci Lett 1987; 81:279-84. [PMID: 2893316 DOI: 10.1016/0304-3940(87)90396-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In halothane-anaesthetized, vagotomized, SA-denervated rats, the activity of various sympathetic nerves has been analyzed with respect to phrenic nerve discharge (an indicator of central respiratory drive (CRD)). The cervical and lumbar sympathetic nerves had maximal activity following, and were least active during phrenic nerve discharge. In contrast, the splanchnic, cardiac, renal and adrenal nerves exhibited their activity peak during phrenic nerve discharge (i.e. inspiration). Similar activity profiles were observed after ganglion blockade in the mixed pre- and postganglionic fibre preparations. These observations indicate that it is the subpopulations of preganglionic neurones and the proportional contribution of each to whole-nerve activity which give rise to the differences in CRD-related activity profiles between nerves.
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Affiliation(s)
- Y Numao
- Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki-ken, Japan
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23
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Kurantsin-Mills J, Jacobs HM, Klug PP, Lessin LS. Flow dynamics of human sickle erythrocytes in the mesenteric microcirculation of the exchange-transfused rat. Microvasc Res 1987; 34:152-67. [PMID: 3670112 DOI: 10.1016/0026-2862(87)90050-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
To analyze the microvascular rheology of sickle cells in an intact animal model, rats were isovolemically exchange transfused with human normal (hemoglobin AA) or sickle (hemoglobin SS) erythrocytes (blood group O) or autologous red cells under ambient conditions, and the effects of the heterologous or autologous cells on (a) hemodynamics and respiration, (b) blood gases, and (c) acid-base status of the recipients were determined. Exchange transfusion of rats with autologous red cells or hemoglobin AA or hemoglobin SS erythrocytes was associated with stable mean arterial blood pressure, central venous pressure, respiration rate, blood pH, pCO2, and pO2 during the experimental period, except for tachycardia among the group of rats that received HbSS cells. Arteriovenous oxygen content varied among the three groups of animals, but, nonetheless, suggested adequate tissue oxygen supply under the conditions of the study. Acid-base status also was similar in the three groups of rats. The exchange-transfused rats were utilized to investigate the flow dynamics of red cells in the mesenteric microcirculation by applying intravital microscopy. Time-averaged velocities of the autologous red cells in 16- to 30-microns (id) vessels ranged from 1.07 to 1.25 mm/sec in single unbranched arterioles with varying flux and wall shear rates. Time-averaged velocities of the HbAA cells in single 15- to 35-microns arterioles ranged from 1.16 to 1.24 mm/sec with wall shear rates similar to the estimates for the autologous cells. For both rat and human HbAA RBCs, the flow dynamics were indicative of normal shear-dependent and deformability characteristics of the cells under the flow conditions. Sickle cells exhibited time-averaged velocities of 0.384 to 0.452 mm/sec, lower wall shear rates in 10- to 35-microns single unbranched arterioles, and three times less volumetric flux. In some arterioles, sickle cells with high axial ratio and low deformability showed definite adhesion to the endothelial surface, residing at such sites for several seconds until dislodged by the force of flow. Within single unbranched vessels or at microvascular bifurcations, sickle elliptocytes and sickle echinocytes with low deformability and high axial ratio obstructed flow and exhibited residence times of 2 to 88 sec, thereby causing stasis. These data illustrate the microvascular flow behavior of sickle cells and demonstrate the rheological disequilibrium state that can result as sickle cells course through successive segments of the microcirculation.
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Affiliation(s)
- J Kurantsin-Mills
- Department of Medicine, George Washington University Medical Center, Washington, D.C. 20037
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24
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Renault G, Muffat-Joly M, Polianski J, Hardy RI, Boutineau JL, Duvent JL, Pocidalo JJ. NADH in situ laser fluorimetry: effect of pentobarbital on continuously monitored myocardial redox state. Lasers Surg Med 1987; 7:339-46. [PMID: 3683065 DOI: 10.1002/lsm.1900070408] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
NADH laser fluorimetry was applied to in situ monitoring of pentobarbital overload effect on myocardial redox state in rats. Experiments were carried out on open-chest rats anesthetized with pentobarbital. Use of very thin optical probes allowed measurements of NADH fluorescence directly within the myocardial wall. Quantitative analysis of fluorescent and backscattered light signals was made possible on-line. In 8 animals, a slow IV infusion of 6% pentobarbital (2 mg.min-1 for 10 min) induced an average twofold increase in NADH fluorescence, with constant return to baseline level prior to injection after a maximum period of 50 min. Thus, pentobarbital overload strongly affects the myocardial energetic state, and this effect was precisely evaluated with NADH fluorescence monitoring. In situ-monitored myocardial redox state variations during pentobarbital infusion can constitute a reference for similar studies on pharmacological agents aimed at protecting tissues against ischemic biochemical damages.
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Affiliation(s)
- G Renault
- INSERM Unité 13, Hôpital Claude Bernard, Paris, France
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25
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Van Nimmen D, Weyne J, Demeester G, Leusen I. Local cerebral glucose utilization during intracerebral pH changes. J Cereb Blood Flow Metab 1986; 6:584-9. [PMID: 3760042 DOI: 10.1038/jcbfm.1986.105] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of ventriculocisternal perfusion with mock CSF with alkaline or acidic pH on the local CMRglu (LCMRglu) in the caudatoputamen was studied in artificially ventilated and relaxed rats. In control rats both lateral cerebral ventricles were perfused with mock CSF at pH 7.4. In the experimental series one cerebral ventricle was infused with normal mock CSF while the other was infused with mock CSF in which the pH was decreased or increased by changing [HCO-3]. LCMRglu was depressed in acidotic brain tissue while it was strongly increased in alkalotic brain tissue. The importance of these alterations in brain glucose metabolism for the homeostatic regulation of brain pH is discussed.
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26
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Bernaudin JF, Theven D, Pinchon MC, Brun-Pascaud M, Bellon B, Pocidalo JJ. Protein transfer in hyperoxic induced pleural effusion in the rat. Exp Lung Res 1986; 10:23-38. [PMID: 3948810 DOI: 10.3109/01902148609057501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In order to study the kinetics and pathways of protein transfer in pleural effusion, rats with pleurisy associated with hyperoxic pulmonary edema were injected either intrapleurally or intravenously with tracers. 125I-Albumin was used to obtain quantitative data. Anti horseradish peroxidase used as a morphological tracer, allowed a precise localization of the pathways used for the transfer. It has been possible to demonstrate that, in this model, the pleural effusion is produced by a plasma exudation accumulated in the lung interstitium, transferred through the visceral pleura and resorbed by the lymphatics of the parietal costal and diaphragmatic pleurae.
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27
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Svendsen P, Carter AM. Influence of injectable anaesthetic combinations on blood gas tensions and acid-base status in laboratory rats. ACTA PHARMACOLOGICA ET TOXICOLOGICA 1985; 57:1-7. [PMID: 3931415 DOI: 10.1111/j.1600-0773.1985.tb00001.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Outbred Mol:SPRD rats were maintained in surgical anaesthesia for two hours by using five different drug combinations: 1) pentobarbitone, 2) ketamine + diazepam, 3) ketamine + pentobarbitone, 4) atropine + diazepam + fentanyl + fluanisone, 5) atropine + etorphine + acepromazine. Respiratory rate, arterial O2 and CO2 tensions, arterial pH, base excess, mean arterial blood pressure and heart rate were recorded at set intervals from 30 to 120 min. from the initiation of anaesthesia. Atropine + diazepam + fentanyl + fluanisone caused no disturbance of acid-base balance, whereas the other drug combinations induced moderate to severe acidosis. Arterial blood pressure was reduced by all methods. Pentobarbitone and regimens including ketamine reduced heart rate, whereas combinations with etorphine and fentanyl caused a rise in heart rate.
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28
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Lioy F, Blinkhorn MT, Garneau C. Regional hemodynamic effects of changes in PaCO2 in the vagotomized, sino-aortic de-afferented rat. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1985; 12:301-13. [PMID: 3923091 DOI: 10.1016/0165-1838(85)90045-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Rats were anesthetized with urethane (1.5 g/kg i.p.) paralyzed with gallamine (3 mg/kg, i.v.), artificially ventilated and the vagi, carotid sinus and aortic nerves were cut. PaCO2 levels of 16.4 +/- 0.8, 23.3 +/- 1.6, 32.3 +/- 1.8 and 51.9 +/- 2.2 mm Hg were obtained by hyperventilation in 0%, 3%, 5% and 8% CO2 in O2, respectively. Radioactive microspheres labelled with 57Co or 113Sn were injected into the left ventricle and cardiac output and regional blood flows were determined by the 'arterial reference sample' method. Increasing PaCO2 induced an increase in systemic arterial pressure which was predominantly due to a significant increase in total peripheral resistance, while the increase in cardiac output was much less pronounced and no changes in heart rate were observed. The effect of increasing PaCO2 on regional vascular resistance (VR) was not uniformly distributed. CO2 induced a dilatation in the cerebral, bronchial and hepatic artery vascular beds. Coronary VR was not affected while vasoconstriction was induced by CO2 in the other vascular territories. This vasoconstriction was most significant in skeletal muscle, skin, pancreas, large intestine and kidneys. In most of these territories the vasoconstrictor effect of CO2 was observed at PaCO2 levels above 23.3 mm Hg, while between 16.4 and 23.3 mm Hg there was either no change or a decrease in VR. Propranolol and phentolamine (1 mg/kg and 10 mg/kg, i.v., respectively), which caused a 78% +/- 2% adrenergic blockade, significantly reduced the CO2 pressor and vasoconstrictor effects. Our experiments show that, after peripheral chemoreceptor denervation in the rat: (a) there is a direct relationship between PaCO2 and VR mediated by the sympathetic nervous system over the whole range of PaCO2 values from hypocapnia to hypercapnia, and (b) the various vascular territories contribute to a different extent to the CO2-induced changes in total peripheral resistance.
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29
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Bar-Ilan A, Marder J, Samueloff S. Blood acid-base status, whole blood and whole body buffer values in sand rats (Psammomys obesus) exposed to hypercapnia. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1985; 81:571-6. [PMID: 2863043 DOI: 10.1016/0300-9629(85)91027-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Arterial blood acid-base status of unanesthetized sand rats (Psammomys obesus) were studied under normocapnic and hypercapnic conditions, and compared to those obtained for the albino rat (Rattus norvegicus). The average control blood pH: 7.396 +/- 0.034; PaCO2: 30.5 +/- 2.9 mmHg; HCO-3: 18.8 +/- 2.5 mM/l; and HCO-3 std: 20.9 +/- 2.1 (N = 15) obtained here for the sand rat are in the lower range of values found in other mammals and indicate a status of partially compensated metabolic acidosis. The blood buffer values of the sand rat, delta log PCO2/delta pH = -2.32 +/- 0.35 (N = 25) are significantly higher than those found here for the rat, delta log PCO2/delta pH = -1.51 +/- 0.10 (N = 39), and those reported for other mammals. This high blood buffer value may be related to the natural high mineral diet of the sand rat. The in vivo (whole body) buffer value delta log PaCO2/delta pH = -1.41 and -1.65 for the sand rat and the rat found here are higher than those reported for the man and dog and may represent a physiological adaptation to the hypercapnic conditions prevailing in underground burrows.
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30
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Bar-Ilan A, Marder J. The effects of the inhibition of the renal carbonic anhydrase on the blood acid-base status in hypercapnic rats. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1985; 81:121-6. [PMID: 2859945 DOI: 10.1016/0300-9629(85)90277-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Arterial blood acid-base status was measured in unanesthetized rats treated with benzolamide (a selective renal carbonic anhydrase inhibitor). These measurements were carried out in rats exposed to different levels of CO2 in air (0-10% CO2) for periods of up to 6 hr. In untreated rats the whole body buffer value showed a continuous increase and after 6 hr of exposure to hypercapnia its value was twice that measured initially. On the other hand, the whole body buffer value of benzolamide treated rats did not change during the 6 hr of exposure to hypercapnia. The whole body buffer value of normal rats, measured after 6 hr of hypercapnia is similar to that reported for chronic (3-5 days) hypercapnia in the normal dog. The whole body buffer value in benzolamide treated rats was similar to that reported for the normal dog and man, during acute CO2 exposures. It is suggested that mechanisms involving the renal carbonic anhydrase are responsible for the significant, rapid changes in the whole body buffer value that take place during the initial phase of acute exposure to CO2 in the rat. This may represent a mechanism of adaptation to burrow hypercapnic conditions.
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31
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Teisseire BP, Soulard CD, Teisseire LJ, Herigault RA, Laurent DN. Induced low P50 in anesthetized rats: blood gas, circulatory and metabolic adjustments. RESPIRATION PHYSIOLOGY 1984; 58:335-44. [PMID: 6528109 DOI: 10.1016/0034-5687(84)90009-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In anesthetized, normoxic or hypoxic rats the hemodynamic, metabolic and O2 transport characteristics following exchange transfusion with human erythrocytes containing a high O2 affinity hemoglobin (Hemoglobin Creteil, beta 89 Ser----Asp) have been studied. The in vivo oxygen partial pressure at 50% oxygen hemoglobin saturation (P50) decreased from 37.4 +/- 2.1 to 12.7 +/- 0.7 mm Hg; the arterial oxygen tension was reduced significantly from 109.9 +/- 7.7 to 87.3 +/- 12.0 mm Hg. There was a decrease in right ventricular partial pressure of oxygen (PvO2), (P less than 0.001), oxygen consumption (VO2), (P less than 0.001), arterio-venous difference, (P less than 0.001), and peripheral vascular resistance index, (P less than 0.01). Exchange transfusion with normal rat blood (P50 = 37.2 +/- 2.4 mm Hg) or with 2,3-diphosphoglycerate-enriched human red blood cells (P50 = 34.7 +/- 2.2 mm Hg), did not modify these variables in normoxic rats. In hypoxia, the reduction in P50 was associated with a further decrease in PvO2 an increase in serum lactate concentration and a VO2 decrease.
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Komarek J. The effect of ether, pentobarbitone sodium and fentanyl on blood gases, acid-base balance and hematological parameters in the rat. EXPERIENTIA 1984; 40:476-8. [PMID: 6426998 DOI: 10.1007/bf01952393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Blood gases, acid-base balance and hematological parameters (RBC, PCV and Hb) were measured in adult rats of both sexes. The use of ether and fentanyl had a very little effect on the blood gases and acid-base balance. The induction of pentobarbitone anesthesia, however, was followed by a significant increase in PCO2 and TCO2, while the pH value decreased.
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Polianski JM, Brun-Pascaud MC, Jelazko PR, Pocidalo JJ. Ventilation in awake rats with permanent arterial catheters. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1984; 77:319-24. [PMID: 6142801 DOI: 10.1016/0300-9629(84)90068-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Respiratory frequency (f), tidal volume (VT) and minute ventilation (VE) were measured in restrained awake rats using a volumetric body plethysmograph excluding the head. An arterial catheter was then implanted and ventilatory measurements performed again two or three days later. Arterial blood gases and acid-base status were measured before entry in the plethysmograph (control values) and after, accompanying each ventilatory measurement. The pattern of ventilation (VT and VE) was significantly correlated with the respiratory status, particularly with PaCO2 (P less than 0.001). A ventilatory (VE, VT, f) and respiratory (PaO2, PaCO2, pH) steady state was obtained from the fifteenth minute to the end of the observation period. The present preparation is a stable experimental model providing respiratory and ventilatory data in the awake rat.
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Girard P, Brun-Pascaud M, Pocidalo JJ. Acid-base status of awake rats after cannulation of aorta and vena cava. Kidney Int 1983; 24:795-9. [PMID: 6674673 DOI: 10.1038/ki.1983.230] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Pocidalo JJ, Brun-Pascaud M, Blayo MC, Azoulay-Dupuis E. Respiratory effects of normobaric oxygen toxicity in awake guinea-pig. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1983; 74:831-6. [PMID: 6861478 DOI: 10.1016/0305-0491(83)90154-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We studied the time course of the respiratory events in awake guinea-pigs catheterized with a chronic arterial cannula, exposed to 100% O2 during 48 hr and after air return breathing. 2. The oxygen toxicity has a pulmonary and respiratory expression: clinical, histological and biochemical data show that death is related to the asphyxia generated by acute pulmonary edema. 3. The O2 toxicity respiratory effects show striking differences in rats and guinea-pigs; the differences belong to a specific and particular lymphatic system in the rat. 4. Rat and guinea pig offer two different models of pulmonary edema, (the first is characterized by absence of arterial hypoxemia) and in consequence two different models of lung oxygen toxicity.
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