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Lang GP, Ndongson-Dongmo B, Lajqi T, Brodhun M, Han Y, Wetzker R, Frasch MG, Bauer R. Impact of ambient temperature on inflammation-induced encephalopathy in endotoxemic mice-role of phosphoinositide 3-kinase gamma. J Neuroinflammation 2020; 17:292. [PMID: 33028343 PMCID: PMC7541275 DOI: 10.1186/s12974-020-01954-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 09/16/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sepsis-associated encephalopathy (SAE) is an early and frequent event of infection-induced systemic inflammatory response syndrome. Phosphoinositide 3-kinase γ (PI3Kγ) is linked to neuroinflammation and inflammation-related microglial activity. In homeotherms, variations in ambient temperature (Ta) outside the thermoneutral zone lead to thermoregulatory responses, mainly driven by a gradually increasing sympathetic activity, and may affect disease severity. We hypothesized that thermoregulatory response to hypothermia (reduced Ta) aggravates SAE in PI3Kγ-dependent manner. METHODS Experiments were performed in wild-type, PI3Kγ knockout, and PI3Kγ kinase-dead mice, which were kept at neutral (30 ± 0.5 °C) or moderately lowered (26 ± 0.5 °C) Ta. Mice were exposed to lipopolysaccharide (LPS, 10 μg/g, from Escherichia coli serotype 055:B5, single intraperitoneal injection)-evoked systemic inflammatory response (SIR) and monitored 24 h for thermoregulatory response and blood-brain barrier integrity. Primary microglial cells and brain tissue derived from treated mice were analyzed for inflammatory responses and related cell functions. Comparisons between groups were made with one-way or two-way analysis of variance, as appropriate. Post hoc comparisons were made with the Holm-Sidak test or t tests with Bonferroni's correction for adjustments of multiple comparisons. Data not following normal distribution was tested with Kruskal-Wallis test followed by Dunn's multiple comparisons test. RESULTS We show that a moderate reduction of ambient temperature triggers enhanced hypothermia of mice undergoing LPS-induced systemic inflammation by aggravated SAE. PI3Kγ deficiency enhances blood-brain barrier injury and upregulation of matrix metalloproteinases (MMPs) as well as an impaired microglial phagocytic activity. CONCLUSIONS Thermoregulatory adaptation in response to ambient temperatures below the thermoneutral range exacerbates LPS-induced blood-brain barrier injury and neuroinflammation. PI3Kγ serves a protective role in suppressing release of MMPs, maintaining microglial motility and reinforcing phagocytosis leading to improved brain tissue integrity. Thus, preclinical research targeting severe brain inflammation responses is seriously biased when basic physiological prerequisites of mammal species such as preferred ambient temperature are ignored.
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Affiliation(s)
- Guang-Ping Lang
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
- Joint International Research Laboratory of Ethnomedicine and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, 563006 China
| | - Bernadin Ndongson-Dongmo
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
- Department of Pharmacology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Trim Lajqi
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
- Department of Neonatology, University Children’s Hospital, Heidelberg, Germany
| | - Michael Brodhun
- Department of Pathology, Helios-Klinikum Erfurt, Erfurt, Germany
| | - Yingying Han
- Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, 60590 Frankfurt, Germany
| | - Reinhard Wetzker
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | | | - Reinhard Bauer
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
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Pauluhn J. Concentration × time analyses of sensory irritants revisited: Weight of evidence or the toxic load approach. That is the question. Toxicol Lett 2019; 316:94-108. [DOI: 10.1016/j.toxlet.2019.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/07/2019] [Accepted: 09/03/2019] [Indexed: 12/25/2022]
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Su H, Song X, Li J, Iqbal MZ, Kenston SSF, Li Z, Wu A, Ding M, Zhao J. Biosafety evaluation of Janus Fe 3O 4-TiO 2 nanoparticles in Sprague Dawley rats after intravenous injection. Int J Nanomedicine 2018; 13:6987-7001. [PMID: 30464454 PMCID: PMC6217909 DOI: 10.2147/ijn.s167851] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Introduction Newly synthesized Janus-structured Fe3O4-TiO2 nanoparticles (NPs) appear to be a promising candidate for the diagnosis and therapy of cancer. Although the toxicity of individual Fe3O4 or TiO2 NPs has been studied extensively, the toxicity of Janus Fe3O4-TiO2 NPs is not clear. Methods In this study, the biosafety of both Janus Fe3O4-TiO2 NPs (20–25 nm) and the maternal material TiO2 NPs (7–10 nm) were evaluated in Sprague Dawley rats after one intravenous injection into the tail vein. Healthy rats were randomly divided into one control group and six experimental groups. Thirty days after treatment, rats were killed, then blood and tissue samples were collected for hematological, biochemical, element-content, histopathological, and Western blot analysis. Results The results show that only a slight Ti element accumulation in the heart, spleen, and liver could be found in the Janus Fe3O4-TiO2 NP groups (P>0.05 compared with control). However, significant Ti element accumulation in the spleen, lungs, and liver was found in the TiO2 NP-treated rats. Both Fe3O4-TiO2 NPs and TiO2 NPs could induce certain histopathological abnormalities. Western blot analysis showed that both NPs could induce certain apoptotic or inflammatory-related molecular protein upregulation in rat livers. A certain degree of alterations in liver function and electrolyte and lipid parameters was also observed in rats treated with both materials. However, compared to Janus structure Fe3O4-TiO2 NP-treated groups, TiO2 NPs at 30 mg/kg showed more severe adverse effects. Conclusion Our results showed that under a low dose (5 mg/kg), both NP types had no significant toxicity in rats. Janus NPs certainly seem less toxic than TiO2 NPs in rats at 30 mg/kg. To ensure safe use of these newly developed Janus NPs in cancer diagnosis and therapy, further animal studies are needed to evaluate long-term bioeffects.
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Affiliation(s)
- Hong Su
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, Ningbo, Zhejiang, 315211, People's Republic of China,
| | - Xin Song
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, Ningbo, Zhejiang, 315211, People's Republic of China,
| | - Juan Li
- Key Laboratory of Magnetic Materials and Devices, Key Laboratory of Additive Manufacturing Materials of Zhejiang Province, Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201, People's Republic of China
| | - Muhammad Zubair Iqbal
- Key Laboratory of Magnetic Materials and Devices, Key Laboratory of Additive Manufacturing Materials of Zhejiang Province, Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201, People's Republic of China
| | - Samuel Selorm Fiati Kenston
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, Ningbo, Zhejiang, 315211, People's Republic of China,
| | - Zhen Li
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, Ningbo, Zhejiang, 315211, People's Republic of China,
| | - Aiguo Wu
- Key Laboratory of Magnetic Materials and Devices, Key Laboratory of Additive Manufacturing Materials of Zhejiang Province, Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201, People's Republic of China
| | - Min Ding
- Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, 26505, USA
| | - Jinshun Zhao
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, Ningbo, Zhejiang, 315211, People's Republic of China,
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Tse K, Sillito R, Keerie A, Collier R, Grant C, Karp NA, Vickers C, Chapman K, Armstrong JD, Redfern WS. Pharmacological validation of individual animal locomotion, temperature and behavioural analysis in group-housed rats using a novel automated home cage analysis system: A comparison with the modified Irwin test. J Pharmacol Toxicol Methods 2018; 94:1-13. [PMID: 29614333 DOI: 10.1016/j.vascn.2018.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 02/07/2018] [Accepted: 03/28/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND The ActualHCA™ system continuously monitors the activity, temperature and behavior of group-housed rats without invasive surgery. The system was validated to detect the contrasting effects of sedative and stimulant test agents (chlorpromazine, clonidine and amphetamine), and compared with the modified Irwin test (mIT) with rectal temperature measurements. METHODS Six male Han Wistar rats per group were used to assess each test agent and vehicle controls in separate ActualHCA™ recordings and mIT. The mIT was undertaken at 15, 30 mins, 1, 2, 4 and 24 h post-dose. ActualHCA™ recorded continuously for 24 h post-dose under 3 experimental conditions: dosed during light phase, dark phase, and light phase with a scheduled cage change at the time of peak effects determined by mIT. RESULTS ActualHCA™ detected an increase stimulated activity from the cage change at 1-2 h post-dose which was obliterated by chlorpromazine and clonidine. Amphetamine increased activity up to 4 h post-dose in all conditions. Temperature from ActualHCA™ was affected by all test agents in all conditions. The mIT showed effects on all 3 test agents up to 4 h post-dose, with maximal effects at 1-2 h post-dose. The maximal effects on temperature from ActualHCA™ differed from mIT. Delayed effects on activity were detected by ActualHCA™, but not on mIT. CONCLUSIONS Continuous monitoring has the advantage of capturing effects over time that may be missed with manual tests using pre-determined time points. This automated behavioural system does not replace the need for conventional methods but could be implemented simultaneously to improve our understanding of behavioural pharmacology.
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Affiliation(s)
- Karen Tse
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK.
| | - Rowland Sillito
- Actual Analytics Ltd, Appleton Tower, 10 Crichton Street, Edinburgh EH8 9LE, UK
| | - Amy Keerie
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Rachel Collier
- Laboratory Animal Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Claire Grant
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Alderley Park, Cheshire SK10 4TG, UK
| | - Natasha A Karp
- Quantitative Biology, Discovery Science, IMED Biotech Unit, AstraZeneca, Cambridge Science Park, Cambridge CB4 0WG, UK
| | - Cathy Vickers
- NC3Rs, Gibbs Building, 215 Euston Road, London NW1 2BE, UK
| | | | - J Douglas Armstrong
- Actual Analytics Ltd, Appleton Tower, 10 Crichton Street, Edinburgh EH8 9LE, UK; School of Informatics, University of Edinburgh, Appleton Tower, 11 Crichton Street, Edinburgh EH8 9LE, UK
| | - William S Redfern
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK
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Mack JM, Moura TM, Lanznaster D, Bobinski F, Massari CM, Sampaio TB, Schmitz AE, Souza LF, Walz R, Tasca CI, Poli A, Doty RL, Dafre AL, Prediger RD. Intranasal administration of sodium dimethyldithiocarbamate induces motor deficits and dopaminergic dysfunction in mice. Neurotoxicology 2018; 66:107-120. [PMID: 29605442 DOI: 10.1016/j.neuro.2018.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 01/26/2023]
Abstract
The primary etiology of Parkinson's disease (PD) remains unclear, but likely reflects a combination of genetic and environmental factors. Exposure to some pesticides, including ziram (zinc dimethyldithiocarbamate), is a relevant risk factor for PD. Like some other environmental neurotoxicants, we hypothesized that ziram can enter the central nervous system from the nasal mucosa via the olfactory nerves. To address this issue, we evaluated the effects of 1, 2 or 4 days of intranasal (i.n., 1 mg/nostril/day) infusions of sodium dimethyldithiocarbamate (NaDMDC), a dimethyldithiocarbamate more soluble than ziram, on locomotor activity in the open field, neurological severity score and rotarod performance. We also addressed the effects of four daily i.n. NaDMDC infusions on olfactory bulb (OB) and striatal measures of cell death, reactive oxygen species (ROS), tyrosine hydroxylase, and the levels of dopamine, noradrenaline, serotonin, and their metabolites. A single i.n. administration of NaDMDC did not significantly alter the behavioral measures. Two consecutive days of i.n. NaDMDC administrations led to a transient neurological deficit that spontaneously resolved within a week. However, the i.n. infusions of NaDMDC for 4 consecutive days induced motor and neurological deficits for up to 7 days after the last NaDMDC administration and increased striatal TH immunocontent and dopamine degradation within a day of the last infusion. Pharmacological treatment with the anti-parkinsonian drugs l-DOPA and apomorphine improved the NaDMDC-induced locomotor deficits. NaDMDC increased serotonin levels and noradrenaline metabolism in the OB 24 h after the last NaDMDC infusion, ROS levels in the OB 2 h after the last infusion, and striatum 2 and 24 h after the last infusion. These results demonstrate, for the first time, that i.n. NaDMDC administration induces neurobehavioral and neurochemical impairments in mice. This accords with evidence that dimethyldithio-carbamate exposure increases the risk of PD and highlights the possibility that olfactory system could be a major route for NaDMDC entry to central nervous system.
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Affiliation(s)
- Josiel M Mack
- Department of Pharmacology, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Tainara M Moura
- Department of Pharmacology, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Débora Lanznaster
- Department of Biochemistry, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Franciane Bobinski
- Experimental Neuroscience Laboratory (LANEX), Graduate Program in Health Sciences, University of Southern of Santa Catarina (UNISUL), Palhoça, SC, Brazil
| | - Caio M Massari
- Department of Biochemistry, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Tuane B Sampaio
- Department of Pharmacology, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Ariana E Schmitz
- Department of Biochemistry, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Luiz F Souza
- Department of Biochemistry, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Roger Walz
- Department of Clinical Medical, Center of Health Sciences, University Hospital, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Carla I Tasca
- Department of Biochemistry, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Anicleto Poli
- Department of Pharmacology, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Richard L Doty
- Smell & Taste Center, Department of Otorhinolaryngology: Head and Neck Surgery, Perelman School of Medicine, Philadelphia, PA 19104 USA
| | - Alcir L Dafre
- Department of Biochemistry, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Rui D Prediger
- Department of Pharmacology, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil.
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Upper respiratory tract nociceptor stimulation and stress response following acute and repeated Cyfluthrin inhalation in normal and pregnant rats: Physiological rat-specific adaptions can easily be misunderstood as adversities. Toxicol Lett 2018; 282:8-24. [DOI: 10.1016/j.toxlet.2017.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 09/27/2017] [Accepted: 10/02/2017] [Indexed: 11/22/2022]
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Redfern WS, Tse K, Grant C, Keerie A, Simpson DJ, Pedersen JC, Rimmer V, Leslie L, Klein SK, Karp NA, Sillito R, Chartsias A, Lukins T, Heward J, Vickers C, Chapman K, Armstrong JD. Automated recording of home cage activity and temperature of individual rats housed in social groups: The Rodent Big Brother project. PLoS One 2017; 12:e0181068. [PMID: 28877172 PMCID: PMC5587114 DOI: 10.1371/journal.pone.0181068] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 06/26/2017] [Indexed: 12/04/2022] Open
Abstract
Measuring the activity and temperature of rats is commonly required in biomedical research. Conventional approaches necessitate single housing, which affects their behavior and wellbeing. We have used a subcutaneous radiofrequency identification (RFID) transponder to measure ambulatory activity and temperature of individual rats when group-housed in conventional, rack-mounted home cages. The transponder location and temperature is detected by a matrix of antennae in a baseplate under the cage. An infrared high-definition camera acquires side-view video of the cage and also enables automated detection of vertical activity. Validation studies showed that baseplate-derived ambulatory activity correlated well with manual tracking and with side-view whole-cage video pixel movement. This technology enables individual behavioral and temperature data to be acquired continuously from group-housed rats in their familiar, home cage environment. We demonstrate its ability to reliably detect naturally occurring behavioral effects, extending beyond the capabilities of routine observational tests and conventional monitoring equipment. It has numerous potential applications including safety pharmacology, toxicology, circadian biology, disease models and drug discovery.
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Affiliation(s)
- William S. Redfern
- Drug Safety and Metabolism, AstraZeneca R&D, Babraham Research Campus, Cambridge, United Kingdom
| | - Karen Tse
- Drug Safety and Metabolism, AstraZeneca R&D, Babraham Research Campus, Cambridge, United Kingdom
| | - Claire Grant
- Drug Safety and Metabolism, AstraZeneca R&D, Alderley Park, Cheshire, United Kingdom
| | - Amy Keerie
- Drug Safety and Metabolism, AstraZeneca R&D, Babraham Research Campus, Cambridge, United Kingdom
| | - David J. Simpson
- Drug Safety and Metabolism, AstraZeneca R&D, Alderley Park, Cheshire, United Kingdom
| | - John C. Pedersen
- Drug Safety and Metabolism, AstraZeneca R&D, Babraham Research Campus, Cambridge, United Kingdom
| | - Victoria Rimmer
- Drug Safety and Metabolism, AstraZeneca R&D, Alderley Park, Cheshire, United Kingdom
| | - Lauren Leslie
- Drug Safety and Metabolism, AstraZeneca R&D, Alderley Park, Cheshire, United Kingdom
| | - Stephanie K. Klein
- Drug Safety and Metabolism, AstraZeneca R&D, Babraham Research Campus, Cambridge, United Kingdom
| | - Natasha A. Karp
- Quantitative Biology, IMED, AstraZeneca, Darwin Building (Unit 310), Cambridge Science Park, Cambridge, United Kingdom
| | | | | | - Tim Lukins
- Actual Analytics Ltd, Edinburgh, United Kingdom
| | | | | | | | - J. Douglas Armstrong
- Actual Analytics Ltd, Edinburgh, United Kingdom
- School of Informatics, University of Edinburgh, Appleton Tower, Edinburgh, United Kingdom
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Weis CP, LaVelle JM. Characteristics to Consider when Choosing an Animal Model for the Study of Lead Bioavailability. CHEMICAL SPECIATION & BIOAVAILABILITY 2015. [DOI: 10.1080/09542299.1991.11083162] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
INTRODUCTION Access to genetically engineered mice has opened many new opportunities to address questions relevant to the pathophysiology and treatment of patients in critical conditions. However, the results of studies in mice cannot disregard the unique ability of small rodents to adjust their temperature and high metabolic rate and the corresponding respiratory and circulatory requirements in response to hypoxia. POINT OF VIEW Studies performed in mice on questions related to metabolic, circulatory, and respiratory regulation should always be considered in light of the ability of mice to rapidly drop their nonshivering thermogenesis-related metabolism. As an example, it has been recently argued that a moderate level of inhaled hydrogen sulfide may have a potential benefit in patients in coma or shock or during an anoxic or ischemic insult, as this toxic gas dramatically reduces the metabolic rate in resting mice. However, acute hypometabolism has long been described in small mammals in response to hypoxia and is not specific to hydrogen sulfide. More importantly, mice have a specific metabolic rate that is 15-20 times higher than the specific metabolic level of a resting human. This difference can be accounted for by the large amount of heat produced by mice through nonshivering thermogenesis, related to the activity of uncoupling proteins. This mechanism, which is essential for maintaining homeothermia in small mammals, is virtually absent in larger animals, including in adult humans. Accordingly, no direct metabolic effect of hydrogen sulfide is observed in large mammals. We present the view that similar reasoning should be applied when the circulatory or respiratory response to hypoxic exposure is considered. This leads us to question whether a similar strategy could occur in mice in critical conditions other than hypoxia, such as in hypovolemic, septic, or cardiogenic shock. CONCLUSION Mouse models developed to understand the mechanisms of protection against hypoxia or ischemia or to propose new therapeutic approaches applicable in critical care patients should be understood in light of the specificity of the metabolic, respiratory, and circulatory responses of mice to a hypoxic insult, since many of these adaptations have no clear equivalent in humans.
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Guzmán A, Marín AP, García C, Fernández de Henestrosa AR, Ruiz MT, Tortajada A, Marcos R. Induction of hypothermic conditions associated with increased micronuclei formation in sigma-1 receptor knockout mice after administration of the antipsychotic compound E-5842. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2008; 49:727-33. [PMID: 18800345 DOI: 10.1002/em.20428] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The antipsychotic sigma-1 (sigma(1)) receptor ligand E-5842 has been shown to increase micronucleated polychromatic erythrocyte (MNPCE) frequency in mouse bone marrow secondary to compound-induced hypothermia. Interaction with sigma(1) receptor has been considered a plausible contributing factor for E-5842-induced hypothermia, raising concern for a possible class effect of sigma receptor ligands in the mouse micronucleus (MN) test. We assessed the potential of E-5842 (200 mg/kg, oral) to produce hypothermic conditions associated with increased micronuclei formation in sigma(1) receptor knockout (sigma(1)R-KO) and wild type (WT) mice. After administration, animal's rectal temperature was recorded and peripheral blood and bone marrow samples were obtained (48 hr) and assessed for induction of micronucleated reticulocytes (MNRET) and MNPCE, respectively. E-5842 administration produced marked hypothermia both in sigma(1)R-KO and WT mice. Maximum decreases from preadministration temperature were 12.2 and 13.5 degrees C in sigma(1)R-KO and WT mice, respectively. Temperature returned to normal approximately 32 hr after administration. Bone marrow examination revealed a statistical significant increase (P < 0.05) in MNPCE frequency both in sigma(1)R-KO and WT animals. Examination of peripheral blood samples showed a slight, although nonstatistical significant, increase in MNRET frequency in sigma(1)R-KO mice. No similar effect was observed among WT animals. The results obtained after E-5842 administration to sigma(1)R-KO mice indicate that induction of hypothermic conditions associated with increased MNPCE formation is not mediated by compound interaction with sigma(1) receptor, ruling out concern for a possible class effect of similar high affinity sigma(1) receptor ligands in the mouse MN test.
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Affiliation(s)
- Antonio Guzmán
- Toxicology Department, ESTEVE, Mare de Déu de Montserrat 221, 08041, Barcelona, Spain.
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Thermoregulatory responses to environmental toxicants: The interaction of thermal stress and toxicant exposure. Toxicol Appl Pharmacol 2008; 233:146-61. [DOI: 10.1016/j.taap.2008.01.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Indexed: 11/23/2022]
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Watkinson WP, Aileru AA, Dowd SM, Doerfler DL, Tepper JS, Costa DL. Acute Effects of Ozone on Heart Rate and Body Temperature in the Unanesthetized, Unrestrained Rat Maintained at Different Ambient Temperatures. Inhal Toxicol 2008. [DOI: 10.3109/08958379309034498] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Gordon CJ, Spencer PJ, Hotchkiss J, Miller DB, Hinderliter PM, Pauluhn J. Thermoregulation and its influence on toxicity assessment. Toxicology 2008; 244:87-97. [DOI: 10.1016/j.tox.2007.10.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Accepted: 10/22/2007] [Indexed: 11/25/2022]
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Ingman K, Sallinen J, Honkanen A, Korpi ER. Comparison of deramciclane to benzodiazepine agonists in behavioural activity of mice and in alcohol drinking of alcohol-preferring rats. Pharmacol Biochem Behav 2004; 77:847-54. [PMID: 15099931 DOI: 10.1016/j.pbb.2004.02.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Revised: 02/19/2004] [Accepted: 02/26/2004] [Indexed: 11/18/2022]
Abstract
Interactions between alcohol and traditional benzodiazepine anxiolytics hamper the treatment of alcoholism-related anxiety disorders. Serotonin 5-HT(2) receptor antagonists, such as deramciclane, are anxiolytic, and considering their pharmacological profile, they might benefit alcoholics with comorbid anxiety. We studied the effects of acute deramciclane (1, 3 and 10 mg/kg i.p.) on alcohol drinking of alcohol-preferring AA rats drinking 10% (vol/vol) ethanol solution in a 4-h limited-access paradigm. Thereafter, a 5-day repeated-treatment experiment was carried out, under corresponding test design, with deramciclane (3 mg/kg i.p.) as a test drug and midazolam (1 mg/kg i.p.) as a benzodiazepine reference compound. Deramciclane had no effect on alcohol consumption in either acute or repeated dosing study. Midazolam increased ethanol drinking, as expected, when administered on successive days. A modified functional observational battery (FOB) procedure was applied to study neurological, behavioural and autonomic effects induced by deramciclane (1-30 mg/kg po) and diazepam (1-30 mg/kg po) in mice at 30 min, 2 h and 4 h after dosing. Deramciclane had a mild dopamine D(2) receptor antagonism-like effect at the highest dose. The effects of diazepam were predictable, myorelaxation-induced motor impairment and anxiolysis-related hyperlocomotion in a novel environment being the characteristic features at the two highest doses. Deramciclane appears to be a safe and well-tolerated drug and we suggest that it might be useful in the treatment of anxiety in alcoholics.
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Affiliation(s)
- Kimmo Ingman
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Itäinen Pitkäkatu 4B, FIN-20520 Turku, Finland.
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Pauluhn J, Schmuck G. Critical analysis of potential body temperature confounders on neurochemical endpoints caused by direct dosing and maternal separation in neonatal mice: a study of bioallethrin and deltamethrin interactions with temperature on brain muscarinic receptors. J Appl Toxicol 2003; 23:9-18. [PMID: 12518331 DOI: 10.1002/jat.873] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present investigation was conducted to understand better possible confounding factors caused by direct dosing of neonatal mice during the pre-weaning developmental period. By direct dosing, pups might encounter thermal challenges when temporarily removed from their 'natural habitat'. Typically, this leads to a cold environment and food deprivation (impaired lactation) and modulation of the toxic potency of the substance administered. Growth retardation as a consequence of such behavioural changes in pups makes it increasingly difficult to differentiate specific from non-specific mechanisms. Neonatal NMRI mice were dosed daily by gavage (0.7 mg kg(-1) body wt.) from postnatal day (PND) 10-16 with S-bioallethrin, deltamethrin or the vehicle. Then the pups, including their non-treated foster dams, were subjected temporarily for 6 h day to a hypo-, normo- or hyperthermic environment, which was followed by normal housing. The measured temperatures in the environmental chambers were ca. 21, 25 and 30 degrees C, respectively. Thus, temperatures in the hypo- and normothermic groups are comparable to the temperatures commonly present in testing laboratories, whereas the hyperthermic condition is that temperature typically present in the 'natural habitat' of pups. A deviation from the normal behaviour of both pups and dams was observed in the hypo- and normothermic groups. In these groups the rectal temperatures of pups were markedly decreased, especially in the early phase of the study (PND 10-12). Neonates that received either test substance displayed changes in body weights and brain weights at terminal sacrifice (PND 17) when subjected temporarily to a non-physiological environment. An enormous influence of environmental temperature on the density of muscarinic receptors in the crude synaptosomal fraction of the cerebral cortex was ascertained. In summary, these results demonstrate that the direct dosing of thermolabile neonatal mice by gavage is subject to significant artefacts that render the interpretation of findings from such studies difficult. It appears that if direct dosing of neonatal pups is mandated, and inhalation is a relevant route of exposure, the combined inhalation exposure of dams with their litters is an alternative procedure that does not cause disruption of the 'natural habitat' of pups. However, owing to their higher ventilation, under such conditions the pups may receive dosages at least double those of the dams.
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Affiliation(s)
- Jürgen Pauluhn
- Institute of Toxicology, Bayer AG, 42096 Wuppertal, Germany.
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17
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Abstract
Reducing body temperature of rodents has been found to improve their survival to ischaemia, hypoxia, chemical toxicants, and many other types of insults. Larger species, including humans, may also benefit from a lower body temperature when recovering from CNS ischaemia and other traumatic insults. Rodents subjected to these insults undergo a regulated hypothermic response (that is, decrease in set point temperature) characterised by preference for cooler ambient temperatures, peripheral vasodilatation, and reduced metabolic rate. However, forced hypothermia (that is, body temperature forced below set point) is the only method used in the study and treatment of human pathological insults. The therapeutic efficacy of the hypothermic treatment is likely to be influenced by the nature of the reduction in body temperature (that is, forced versus regulated). Homeostatic mechanisms counter forced reductions in body temperature resulting in physiological stress and decreased efficacy of the hypothermic treatment. On the other hand, regulated hypothermia would seem to be the best means of achieving a therapeutic benefit because thermal homeostatic systems mediate a controlled reduction in core temperature.
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Affiliation(s)
- C J Gordon
- Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
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18
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Abstract
1. Dysfunction of the thermoregulatory system is one of many pathologies documented in experimental animals and humans exposed to toxic chemicals. The mechanism of action responsible for many types of poison-induced fevers is not understood. Some elevations in body temperature are attributed to the peripheral actions of some poisons that stimulate metabolic rate and cause a forced hyperthermia. Exposure to organophosphate (OP) pesticides and certain metal fumes appears to cause a prolonged, regulated elevation in body temperature (Tb). 2. Activation of cyclo-oxygenase (COX) and the production of prostaglandin (PG)E2 in central nervous system (CNS) thermoregulatory centres is required to elicit a fever. Activating the COX-PGE2 pathway by a poison may occur by one of three mechanisms: (i) induction of cell-mediated immune responses and the subsequent release of cytokines; (ii) induction of lipid peroxidation in the CNS; and (iii) direct neurochemical activation. 3. Radiotelemetric monitoring of core temperature in unstressed rodents has led to an experimental animal model of poison-induced fever. Rats administered the OP agents chlorpyrifos and diisopropyl fluorophosphate display an initial hypothermic response lasting approximately 24 h, followed by an elevation in diurnal core temperature for 24-72 h after exposure. The hyperthermia is apparently a result of the activation of the COX-PGE2 pathway because it is blocked by the anti-pyretic sodium salicylate. Overall, the delayed hyperthermia resulting from OP exposure involves activation of thermoregulatory pathways that may be similar to infection-mediated fever.
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Affiliation(s)
- C J Gordon
- Neurotoxicology Division, National Health Effects and Environmental Research Laboratory, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
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19
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Gordon CJ, Yang Y. Thermoregulatory response to chemical toxicants and other insults. Extrapolation from experimental animal to human. Ann N Y Acad Sci 1997; 813:835-48. [PMID: 9100976 DOI: 10.1111/j.1749-6632.1997.tb51789.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- C J Gordon
- Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
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Gordon CJ. Thermoregulatory aspects of environmental exposure to anticholinesterase agents. REVIEWS ON ENVIRONMENTAL HEALTH 1996; 11:101-117. [PMID: 9000302 DOI: 10.1515/reveh.1996.11.3.101] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Anticholinesterase (antiChE) agents can be highly toxic to birds and mammals and constitute a major proportion of the pesticides used throughout the world. AntiChEs consist of the organophosphates (OP), which irreversibly inhibit the enzyme acetylcholinesterase (AChE), and the carbamates (CB), which reversibly inhibit AChE. AChE inhibition elicits cholinergic stimulation in the central nervous system and in peripheral tissues and organs, which can lead to marked dysfunction of homeostatic systems, including temperature regulation. The control of body temperature uses cholinergic pathways in the integration and central processing of thermal information, as well as in the control of thermoeffector responses. Hence, the cholinergic stimulation elicited from exposure to antiChEs has profound effects on body temperature at rest as well as during exercise. Ambient heat and cold stress can also modulate the animal's sensitivity to antiChE exposure. After exposure to most OPs, rodents and other small species undergo a marked hypothermic response lasting up to 24 hours. On the other hand, humans exposed to OP pesticides rarely become hypothermic but rather experience a fever that may last many days. Recent studies monitoring body temperature in OP-exposed, telemetered rats demonstrated that the initial hypothermic response is followed by a period of hyperthermia lasting several days. That the hyperthermia can be blocked with administration of sodium salicylate suggests that the hyperthermia is a fever. Thus, the antiChE-induced effects on body temperature and other physiological systems cannot be explained solely by the immediate consequences of AChE inhibition and stimulation of cholinergic systems. Research into the mechanisms of action of antiChE toxicity will be improved with a better understanding of their effects on temperature regulation.
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Affiliation(s)
- C J Gordon
- Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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21
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Watkinson WP, Gordon CJ. Caveats regarding the use of the laboratory rat as a model for acute toxicological studies: modulation of the toxic response via physiological and behavioral mechanisms. Toxicology 1993; 81:15-31. [PMID: 8103612 DOI: 10.1016/0300-483x(93)90153-j] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The rodent, specifically the laboratory rat, is the primary experimental animal used in toxicology testing. Despite its popularity, recent studies from our laboratory and others raise a number of questions concerning the rat's appropriateness as an animal model for toxicological studies. While there may be additional areas in which the rat and other small rodents fail to adequately mimic the human response to xenobiotic agents, this article will focus on the area of temperature regulation. Thus, this article will review the thermoregulatory response of the laboratory rat following acute exposure to toxic agents and examine the impact of this response on the extrapolation of toxicological data from experimental animals to humans. In general, the rat responds to acute intoxication by lowering its core temperature via both physiological and behavioral mechanisms, thereby attenuating the induced toxicity. Similar responses have not been reported in humans.
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Affiliation(s)
- W P Watkinson
- Environmental Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
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