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Yang T, Wang Z, Li J, Shan F, Huang QY. Cerebral Lactate Participates in Hypoxia-induced Anapyrexia Through its Receptor G Protein-coupled Receptor 81. Neuroscience 2024; 536:119-130. [PMID: 37979840 DOI: 10.1016/j.neuroscience.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 10/25/2023] [Accepted: 11/14/2023] [Indexed: 11/20/2023]
Abstract
Hypoxia-induced anapyrexia is thought to be a regulated decrease in body core temperature (Tcore), but the underlying mechanism remains unclear. Recent evidence suggests that lactate, a glycolysis product, could modulate neuronal excitability through the G protein-coupled receptor 81 (GPR81). The present study aims to elucidate the role of central lactate and GPR81 in a rat model of hypoxia-induced anapyrexia. The findings revealed that hypoxia (11.1% O2, 2 h) led to an increase in lactate in cerebrospinal fluid (CSF) and a decrease in Tcore. Injection of dichloroacetate (DCA, 5 mg/kg, 1 μL), a lactate production inhibitor, to the third ventricle (3 V), alleviated the increase in CSF lactate and the decrease in Tcore under hypoxia. Immunofluorescence staining showed GPR81 was expressed in the preoptic area of hypothalamus (PO/AH), the physiological thermoregulation integration center. Under normoxia, injection of GPR81 agonist 3-chloro-5-hydroxybenzoic acid (CHBA, 0.05 mg/kg, 1 μL) to the 3 V, reduced Tcore significantly. In addition, hypoxia led to a dramatic increase in tail skin temperature and a decrease in interscapular brown adipose tissue skin temperature. The number of c-Fos+ cells in the PO/AH increased after exposure to 11.1% O2 for 2 h, but administration of DCA to the 3 V blunted this response. Injection of CHBA to the 3 V also increased the number of c-Fos+ cells in the PO/AH under normoxia. In light of these, our research has uncovered the pivotal role of central lactate-GPR81 signaling in anapyrexia, thereby providing novel insights into the mechanism of hypoxia-induced anapyrexia.
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Affiliation(s)
- Tian Yang
- Department of Frigid Zone Medicine, College of High Altitude Military Medicine, Army Medical University, Chongqing 400038, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing 400038, China; Key Laboratory of High Altitude Medicine, PLA, Chongqing 400038, China
| | - Zejun Wang
- Department of Frigid Zone Medicine, College of High Altitude Military Medicine, Army Medical University, Chongqing 400038, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing 400038, China; Key Laboratory of High Altitude Medicine, PLA, Chongqing 400038, China
| | - Junxia Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Traumatic Shock and Transfusion, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Fabo Shan
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Army Occupational Disease, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing 400042, China.
| | - Qing-Yuan Huang
- Department of Frigid Zone Medicine, College of High Altitude Military Medicine, Army Medical University, Chongqing 400038, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing 400038, China; Key Laboratory of High Altitude Medicine, PLA, Chongqing 400038, China.
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2
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Devereaux MEM, Pamenter ME. Adenosine and γ-aminobutyric acid partially regulate metabolic and ventilatory responses of Damaraland mole-rats to acute hypoxia. J Exp Biol 2023; 226:jeb246186. [PMID: 37694288 PMCID: PMC10565114 DOI: 10.1242/jeb.246186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/01/2023] [Indexed: 09/12/2023]
Abstract
Fossorial Damaraland mole-rats (Fukomys damarensis) mount a robust hypoxic metabolic response (HMR) but a blunted hypoxic ventilatory response (HVR) to acute hypoxia. Although these reflex physiological responses have been described previously, the underlying signalling pathways are entirely unknown. Of particular interest are contributions from γ-aminobutyric acid (GABA), which is the primary inhibitory neurotransmitter in the nervous system of most adult mammals, and adenosine, the accumulation of which increases during hypoxia as a breakdown product of ATP. Therefore, we hypothesized that GABAergic and/or adenosinergic signalling contributes to the blunted HVR and robust HMR in Damaraland mole-rats. To test this hypothesis, we injected adult animals with saline alone (controls), or 100 mg kg-1 aminophylline or 1 mg kg-1 bicuculline, to block adenosine or GABAA receptors, respectively. We then used respirometry, plethysmography and thermal RFID probes to non-invasively measure metabolic, ventilator and thermoregulatory responses, respectively, to acute hypoxia (1 h in 5 or 7% O2) in awake and freely behaving animals. We found that bicuculline had relatively minor effects on metabolism and thermoregulation but sensitized ventilation such that the HVR became manifest at 7% instead of 5% O2 and was greater in magnitude. Aminophylline increased metabolic rate, ventilation and body temperature in normoxia, and augmented the HMR and HVR. Taken together, these findings indicate that adenosinergic and GABAergic signalling play important roles in mediating the robust HMR and blunted HVR in Damaraland mole-rats.
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Affiliation(s)
| | - Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada
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3
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Ma WX, Yuan PC, Zhang H, Kong LX, Lazarus M, Qu WM, Wang YQ, Huang ZL. Adenosine and P1 receptors: Key targets in the regulation of sleep, torpor, and hibernation. Front Pharmacol 2023; 14:1098976. [PMID: 36969831 PMCID: PMC10036772 DOI: 10.3389/fphar.2023.1098976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Graphical AbstractAdenosine mediates sleep, torpor and hibernation through P1 receptors. Recent reasearch has shown that P1 receptors play a vital role in the regulation of sleep-wake, torpor and hibernation-like states. In this review, we focus on the roles and neurobiological mechanisms of the CNS adenosine and P1 receptors in these three states. Among them, A1 and A2A receptors are key targets for sleep-wake regulation, A1Rs and A3Rs are very important for torpor induction, and activation of A1Rs is sufficient for hibernation-like state.
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Affiliation(s)
- Wei-Xiang Ma
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ping-Chuan Yuan
- Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, School of Pharmacy, Wannan Medical College, Wuhu, China
| | - Hui Zhang
- Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, School of Pharmacy, Wannan Medical College, Wuhu, China
| | - Ling-Xi Kong
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine (WPI-IIIS) and Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Wei-Min Qu
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
| | - Yi-Qun Wang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
| | - Zhi-Li Huang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
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4
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Kaufmann M, Mense L, Springer L, Dekker J. Tactile stimulation in the delivery room: past, present, future. A systematic review. Pediatr Res 2022:10.1038/s41390-022-01945-9. [PMID: 35124690 DOI: 10.1038/s41390-022-01945-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/05/2021] [Accepted: 12/14/2021] [Indexed: 11/08/2022]
Abstract
In current resuscitation guidelines, tactile stimulation is recommended for infants with insufficient respiratory efforts after birth. No recommendations are made regarding duration, onset, and method of stimulation. Neither is mentioned how tactile stimulation should be applied in relation to the gestational age. The aim was to review the physiological mechanisms of respiratory drive after birth and to identify and structure the current evidence on tactile stimulation during neonatal resuscitation. A systematic review of available data was performed using PubMed, covering the literature up to April 2021. Two independent investigators screened the extracted references and assessed their methodological quality. Six studies were included. Tactile stimulation management, including the onset of stimulation, overall duration, and methods as well as the effect on vital parameters was analyzed and systematically presented. Tactile stimulation varies widely between, as well as within different centers and no consensus exists which stimulation method is most effective. Some evidence shows that repetitive stimulation within the first minutes of resuscitation improves oxygenation. Further studies are warranted to optimize strategies to support spontaneous breathing after birth, assessing the effect of stimulating various body parts respectively within different gestational age groups.
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Affiliation(s)
- M Kaufmann
- Division of Neonatology and Paediatric Intensive Care Medicine, Department of Paediatrics, Medical Faculty, TU Dresden, Dresden, Germany.
| | - L Mense
- Division of Neonatology and Paediatric Intensive Care Medicine, Department of Paediatrics, Medical Faculty, TU Dresden, Dresden, Germany
- Saxony Center for Feto-Neonatal Health, Medical Faculty, TU Dresden, Dresden, Germany
| | - L Springer
- Division of Neonatology, Department of Paediatrics, University Children's Hospital Tuebingen, Tuebingen, Germany
| | - J Dekker
- Division of Neonatology, Department of Paediatrics, Leiden University Medical Center, Leiden, The Netherlands
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5
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Ripamonte GC, Bernardes-Ribeiro M, Patrone LGA, Vicente MC, Bícego KC, Gargaglioni LH. Functional role for preoptic CB1 receptors in breathing and thermal control. Neurosci Lett 2020; 732:135021. [PMID: 32454147 DOI: 10.1016/j.neulet.2020.135021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 04/12/2020] [Accepted: 04/27/2020] [Indexed: 11/30/2022]
Abstract
The anteroventral preoptic region (AVPO) of the hypothalamus is involved in both temperature and breathing regulation. This area densely express cannabinoid receptors type 1 (CB1) that modulate both excitatory and inhibitory synaptic transmission. However, it is still unknown if the endocannabinoid system located in the AVPO participates in breathing control and thermoregulation. Therefore, we tested the participation of CB1 in the AVPO in the modulation of ventilation and thermal control during normoxia and hypoxia. To this end, body temperature (Tb) of Wistar rats was monitored by datallogers and ventilation (VE) by whole body plethysmography before and after intra-AVPO microinjection of AM-251 (CB1 antagonist, 50 and 100 pmol) followed by 60 min of hypoxia exposure (7% O2). Intra-AVPO microinjection of the higher dose of AM-251 increased VE but did not change Tb under resting conditions. Exposure of rats to 7% of inspired oxygen evoked typical hypoxia-induced anapyrexia and hyperventilation after vehicle microinjection. The higher dose of the cannabinoid antagonist increased the hypoxia-induced hyperventilation, in the same magnitude as observed under normoxic condition, whereas the drop in Tb elicited by hypoxia was attenuated. Therefore, the present results demonstrate that the endocannabinoid system acting on CB1 receptors in the AVPO exerts a tonic inhibitory modulation on breathing but seem not be involved in thermoregulation during resting conditions. In addition, activation of CB1 receptors in the AVPO stimulate thermal response during hypoxia, reducing energetically expensive responses, such as the hypoxic hyperventilation.
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Affiliation(s)
- Gabriel C Ripamonte
- Department of Animal Morphology and Physiology, Sao Paulo State University, UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Mariana Bernardes-Ribeiro
- Department of Animal Morphology and Physiology, Sao Paulo State University, UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Luis Gustavo A Patrone
- Department of Animal Morphology and Physiology, Sao Paulo State University, UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Mariane C Vicente
- Department of Animal Morphology and Physiology, Sao Paulo State University, UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, Sao Paulo State University, UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, Sao Paulo State University, UNESP/FCAV at Jaboticabal, SP, Brazil.
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6
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Solevåg AL, Schmölzer GM, Cheung PY. Novel interventions to reduce oxidative-stress related brain injury in neonatal asphyxia. Free Radic Biol Med 2019; 142:113-122. [PMID: 31039399 DOI: 10.1016/j.freeradbiomed.2019.04.028] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 04/15/2019] [Accepted: 04/23/2019] [Indexed: 01/10/2023]
Abstract
Perinatal asphyxia-induced brain injury may present as hypoxic-ischemic encephalopathy in the neonatal period, and disability including cerebral palsy in the long term. The brain injury is secondary to both the hypoxic-ischemic event and the reoxygenation-reperfusion following resuscitation. Early events in the cascade of brain injury can be classified as either inflammation or oxidative stress through the generation of free radicals. The objective of this paper is to present efforts that have been made to limit the oxidative stress associated with hypoxic-ischemic encephalopathy. In the acute phase of ischemia/hypoxia and reperfusion/reoxygenation, the outcomes of asphyxiated infants can be improved by optimizing the initial delivery room stabilization. Interventions include limiting oxygen exposure, and shortening the time to return of spontaneous circulation through improved methods for supporting hemodynamics and ventilation. Allopurinol, melatonin, noble gases such as xenon and argon, and magnesium administration also target the acute injury phase. Therapeutic hypothermia, N-acetylcysteine2-iminobiotin, remote ischemic postconditioning, cannabinoids and doxycycline target the subacute phase. Erythropoietin, mesenchymal stem cells, topiramate and memantine could potentially limit injury in the repair phase after asphyxia. To limit the injurious biochemical processes during the different stages of brain injury, determination of the stage of injury in any particular infant remains essential. Currently, therapeutic hypothermia is the only established treatment in the subacute phase of asphyxia-induced brain injury. The effects and side effects of oxidative stress reducing/limiting medications may however be difficult to predict in infants during therapeutic hypothermia. Future neuroprotection in asphyxiated infants may indeed include a combination of therapies. Challenges include timing, dosing and administration route for each neuroprotectant.
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Affiliation(s)
- A L Solevåg
- Department of Pediatric and Adolescent Medicine, Akershus University Hospital, Lørenskog, Norway
| | - G M Schmölzer
- Centre for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Alberta, Canada; Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - P-Y Cheung
- Centre for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Alberta, Canada; Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
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7
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Ivy CM, Lague SL, York JM, Chua BA, Alza L, Cheek R, Dawson NJ, Frappell PB, McCracken KG, Milsom WK, Scott GR. Control of breathing and respiratory gas exchange in high-altitude ducks native to the Andes. ACTA ACUST UNITED AC 2019; 222:jeb.198622. [PMID: 30846536 DOI: 10.1242/jeb.198622] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/03/2019] [Indexed: 11/20/2022]
Abstract
We examined the control of breathing and respiratory gas exchange in six species of high-altitude duck that independently colonized the high Andes. We compared ducks from high-altitude populations in Peru (Lake Titicaca at ∼3800 m above sea level; Chancay River at ∼3000-4100 m) with closely related populations or species from low altitude. Hypoxic ventilatory responses were measured shortly after capture at the native altitude. In general, ducks responded to acute hypoxia with robust increases in total ventilation and pulmonary O2 extraction. O2 consumption rates were maintained or increased slightly in acute hypoxia, despite ∼1-2°C reductions in body temperature in most species. Two high-altitude taxa - yellow-billed pintail and torrent duck - exhibited higher total ventilation than their low-altitude counterparts, and yellow-billed pintail exhibited greater increases in pulmonary O2 extraction in severe hypoxia. In contrast, three other high-altitude taxa - Andean ruddy duck, Andean cinnamon teal and speckled teal - had similar or slightly reduced total ventilation and pulmonary O2 extraction compared with low-altitude relatives. Arterial O2 saturation (S aO2 ) was elevated in yellow-billed pintails at moderate levels of hypoxia, but there were no differences in S aO2 in other high-altitude taxa compared with their close relatives. This finding suggests that improvements in S aO2 in hypoxia can require increases in both breathing and haemoglobin-O2 affinity, because the yellow-billed pintail was the only high-altitude duck with concurrent increases in both traits compared with its low-altitude relative. Overall, our results suggest that distinct physiological strategies for coping with hypoxia can exist across different high-altitude lineages, even among those inhabiting very similar high-altitude habitats.
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Affiliation(s)
- Catherine M Ivy
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Sabine L Lague
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Julia M York
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.,Department of Integrative Biology, University of Texas at Austin, TX 78712, USA
| | - Beverly A Chua
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Luis Alza
- Department of Biology and Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Coral Gables, FL 33146, USA.,Division of Ornithology, Centro de Ornitologia y Biodiversidad, Lima 33, Peru.,Department of Biology and Wildlife, Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, AK 99755, USA
| | - Rebecca Cheek
- Department of Biology and Wildlife, Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, AK 99755, USA
| | - Neal J Dawson
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Peter B Frappell
- Zoology Department, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Kevin G McCracken
- Department of Biology and Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Coral Gables, FL 33146, USA.,Division of Ornithology, Centro de Ornitologia y Biodiversidad, Lima 33, Peru.,Department of Biology and Wildlife, Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, AK 99755, USA.,Human Genetics and Genomics, University of Miller School of Medicine, Miami, FL 33136, USA
| | - William K Milsom
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Graham R Scott
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
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8
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Abstract
In some organisms and cells, oxygen availability influences oxygen consumption. In this review, we examine this phenomenon of hypoxic hypometabolism (HH), discussing its features, mechanisms, and implications. Small mammals and other vertebrate species exhibit "oxyconformism," a downregulation of metabolic rate and body temperature during hypoxia which is sensed by the central nervous system. Smaller body mass and cooler ambient temperature contribute to a high metabolic rate in mammals. It is this hypermetabolic state that is suppressed by hypoxia leading to HH. Larger mammals including humans do not exhibit HH. Tissues and cells also exhibit reductions in respiration during hypoxia in vitro, even at oxygen levels ample for mitochondrial oxidative phosphorylation. The mechanisms of cellular HH involve intracellular oxygen sensors including hypoxia-inducible factors, AMP-activated protein kinase (AMPK), and mitochondrial reactive oxygen species (ROS) which downregulate mitochondrial activity and ATP utilization. HH has a profound impact on cardiovascular, respiratory, and metabolic physiology in rodents. Therefore, caution should be exercised when extrapolating the results of rodent hypoxia studies to human physiology.
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Drew KL, Frare C, Rice SA. Neural Signaling Metabolites May Modulate Energy Use in Hibernation. Neurochem Res 2017; 42:141-150. [PMID: 27878659 PMCID: PMC5284051 DOI: 10.1007/s11064-016-2109-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/05/2016] [Accepted: 11/11/2016] [Indexed: 12/23/2022]
Abstract
Despite an epidemic in obesity and metabolic syndrome limited means exist to effect adiposity or metabolic rate other than life style changes. Here we review evidence that neural signaling metabolites may modulate thermoregulatory pathways and offer novel means to fine tune energy use. We extend prior reviews on mechanisms that regulate thermogenesis and energy use in hibernation by focusing primarily on the neural signaling metabolites adenosine, AMP and glutamate.
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Affiliation(s)
- Kelly L Drew
- Department of Chemistry and Biochemistry, Institute of Arctic Biology, University of Alaska Fairbanks, 902 N. Koyukuk Drive, Fairbanks, AK, 99775, USA.
| | - Carla Frare
- Department of Chemistry and Biochemistry, Institute of Arctic Biology, University of Alaska Fairbanks, 902 N. Koyukuk Drive, Fairbanks, AK, 99775, USA
| | - Sarah A Rice
- Department of Chemistry and Biochemistry, Institute of Arctic Biology, University of Alaska Fairbanks, 902 N. Koyukuk Drive, Fairbanks, AK, 99775, USA
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10
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Fernández RAR, Soriano RN, Francescato HDC, Sabino JP, Coimbra TM, Branco LGS. Cryogenic role of central endogenous hydrogen sulfide in the rat model of endotoxic shock. Brain Res 2016; 1650:218-223. [PMID: 27592137 DOI: 10.1016/j.brainres.2016.08.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 07/13/2016] [Accepted: 08/30/2016] [Indexed: 01/25/2023]
Abstract
Thermoregulatory responses to lipopolysaccharide (LPS) are affected by modulators that increase (propyretic) or decrease (cryogenic) body temperature (Tb). We tested the hypothesis that central hydrogen sulfide (H2S) acts as a thermoregulatory modulator and that H2S production in the anteroventral preoptic region of the hypothalamus (AVPO) is increased during hypothermia and decreased during fever induced by bacterial lipopolysaccharide (LPS, 2.5mg/kg i.p.) in rats kept at an ambient temperature of 25°C. Deep Tb was recorded before and after pharmacological inhibition of the enzyme cystathionine β-synthase (CBS - responsible for H2S endogenous production in the brain) combined or not with LPS administration. To further investigate the mechanisms responsible for these thermoregulatory adjustments, we also measured prostaglandin D2 (PGD2) production in the AVPO. LPS caused typical hypothermia followed by fever. Levels of AVPO H2S were significantly increased during hypothermia when compared to both euthermic and febrile rats. Intracerebroventricular (icv) microinjection of aminooxyacetate (AOA, a CBS inhibitor; 100 pmol) neither affected Tb nor basal PGD2 production during euthermia. In LPS-treated rats, AOA caused increased Tb values during hypothermia, along with enhanced PGD2 production. We conclude that the gaseous messenger H2S modulates hypothermia during endotoxic shock, acting as a cryogenic molecule.
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Affiliation(s)
- Rodrigo A R Fernández
- Medical School of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Renato N Soriano
- Division of Physiology and Biophysics, Department of Basic Life Sciences, Federal University of Juiz de Fora, 35020-220 Governador Valadares, MG, Brazil
| | - Heloísa D C Francescato
- Medical School of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - João P Sabino
- Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, São Paulo, Brazil
| | - Terezila M Coimbra
- Medical School of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Luiz G S Branco
- Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, São Paulo, Brazil.
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11
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Pamenter ME, Dzal YA, Milsom WK. Adenosine receptors mediate the hypoxic ventilatory response but not the hypoxic metabolic response in the naked mole rat during acute hypoxia. Proc Biol Sci 2016; 282:20141722. [PMID: 25520355 DOI: 10.1098/rspb.2014.1722] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Naked mole rats are the most hypoxia-tolerant mammals identified; however, the mechanisms underlying this tolerance are poorly understood. Using whole-animal plethysmography and open-flow respirometry, we examined the hypoxic metabolic response (HMR), hypoxic ventilatory response (HVR) and hypoxic thermal response in awake, freely behaving naked mole rats exposed to 7% O₂ for 1 h. Metabolic rate and ventilation each reversibly decreased 70% in hypoxia (from 39.6 ± 2.9 to 12.1 ± 0.3 ml O₂ min(-1) kg(-1), and 1412 ± 244 to 417 ± 62 ml min(-1) kg(-1), respectively; p < 0.05), whereas body temperature was unchanged and animals remained awake and active. Subcutaneous injection of the general adenosine receptor antagonist aminophylline (AMP; 100 mg kg(-1), in saline), but not control saline injections, prevented the HVR but had no effect on the HMR. As a result, AMP-treated naked mole rats exhibited extreme hyperventilation in hypoxia. These animals were also less tolerant to hypoxia, and in some cases hypoxia was lethal following AMP injection. We conclude that in naked mole rats (i) hypoxia tolerance is partially dependent on profound hypoxic metabolic and ventilatory responses, which are equal in magnitude but occur independently of thermal changes in hypoxia, and (ii) adenosine receptors mediate the HVR but not the HMR.
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Affiliation(s)
- Matthew E Pamenter
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Yvonne A Dzal
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - William K Milsom
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
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12
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Drew KL, Romanovsky AA, Stephen TKL, Tupone D, Williams RH. Future approaches to therapeutic hypothermia: a symposium report. Temperature (Austin) 2015; 2:168-71. [PMID: 27227020 PMCID: PMC4843898 DOI: 10.4161/23328940.2014.976512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 10/09/2014] [Accepted: 10/09/2014] [Indexed: 12/22/2022] Open
Key Words
- A1AR
- AGS, arctic ground squirrel
- CE, capillary electrophoresis
- EEG,electroencephalogram
- FSCV, Fast scan cyclic voltammetry
- HPLC, high performance liquid chromatography
- ICV, intracerebroventricular
- TRPM8
- Tb, core body temperature
- adenosine
- capillary electrophoresis
- hibernation
- nNOS, neuronal nitric oxide synthase; NTS, nucleus tractus solitarii; TH, therapeutic hypothermia; TRP, transient receptor potential [channel(s)]; TRPM8, TRP melastatin-8
- nNOS/NK1
- targeted temperature management
- therapeutic hypothermia
- torpor
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Affiliation(s)
- Kelly L Drew
- Institute of Arctic Biology; University of Alaska Fairbanks; Fairbanks, AK, USA
| | - Andrej A Romanovsky
- Systemic Inflammation Laboratory (Fever Lab); Trauma Research, St. Joseph's Hospital and Medical Center; Phoenix, AZ, USA
| | - Terilyn KL Stephen
- Department of Chemistry and Biochemistry; University of Alaska Fairbanks; Fairbanks, AK, USA
| | - Domenico Tupone
- Department of Neurological Surgery; Oregon Health & Science University; Portland, OR, USA
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Donatti AF, Soriano RN, Sabino JP, Branco LGS. Involvement of endogenous hydrogen sulfide (H2S) in the rostral ventrolateral medulla (RVLM) in hypoxia-induced hypothermia. Brain Res Bull 2014; 108:94-9. [PMID: 25262576 DOI: 10.1016/j.brainresbull.2014.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/01/2014] [Accepted: 08/28/2014] [Indexed: 01/06/2023]
Abstract
Hypoxia evokes a regulated decrease in deep body temperature (Tb). Hydrogen sulfide (H2S), a signaling molecule that belongs to the gasotransmitter family, has been demonstrated to participate in several brain-mediated responses. Rostral ventrolateral medulla (RVLM) is a brainstem region involved in thermoregulation. Recently, it has been shown that exogenous H2S modulates RVLM activity. In the present study, we investigated whether endogenously produced H2S in the RVLM plays a role in the control of hypoxia-induced hypothermia. Tb was measured before and after bilateral microinjection of aminooxyacetate (AOA, 0.2, 1 and 2 pmol/100 nl, a cystathionine β-synthase, CBS, inhibitor) or vehicle into the RVLM followed by a 60-min normoxia (21% inspired O2) or hypoxia (7% inspired O2) exposure. Microinjection of AOA or vehicle did not change Tb during normoxia. Exposure to hypoxia evoked a typical decrease in Tb. Microinjection of AOA (2 pmol) into the RVLM followed by hypoxia significantly attenuated the decrease in Tb. Thus, endogenous H2S in the RVLM seems to play no role in the maintenance of basal Tb, whereas during hypoxia this gas plays a cryogenic role. Moreover, RVLM homogenates of rats exposed to hypoxia exhibited a decreased rate of H2S production. Our data are consistent with the notion that during hypoxia H2S synthesis is diminished in the RVLM facilitating hypothermia.
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Affiliation(s)
- Alberto F Donatti
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil
| | - Renato N Soriano
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil
| | - João P Sabino
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil
| | - Luiz G S Branco
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil.
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Kwiatkoski M, Soriano RN, da Silva GSF, Francescato HD, Coimbra TM, Glass ML, Carnio EC, Branco LGS. Endogenous preoptic hydrogen sulphide attenuates hypoxia-induced hyperventilation. Acta Physiol (Oxf) 2014; 210:913-27. [PMID: 24119224 DOI: 10.1111/apha.12177] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 07/06/2013] [Accepted: 09/26/2013] [Indexed: 11/27/2022]
Abstract
AIM We hypothesized that hydrogen sulphide (H2 S), acting specifically in the anteroventral preoptic region (AVPO - an important integrating site of thermal and cardiorespiratory responses to hypoxia in which H2 S synthesis has been shown to be increased under hypoxic conditions), modulates the hypoxic ventilatory response. METHODS To test this hypothesis, we measured pulmonary ventilation (V˙E) and deep body temperature of rats before and after intracerebroventricular (icv) or intra-AVPO microinjection of aminooxyacetate (AOA; CBS inhibitor) or Na2 S (H2 S donor) followed by 60 min of hypoxia exposure (7% O2 ). Furthermore, we assessed the AVPO levels of H2 S of rats exposed to hypoxia. Control rats were kept under normoxia. RESULTS Microinjection of vehicle, AOA or Na2 S did not change V˙E under normoxic conditions. Hypoxia caused an increase in ventilation, which was potentiated by microinjection of AOA because of a further augmented tidal volume. Conversely, treatment with Na2 S significantly attenuated this response. The in vivo H2 S data indicated that during hypoxia the lower the deep body temperature the smaller the degree of hyperventilation. Under hypoxia, H2 S production was found to be increased in the AVPO, indicating that its production is responsive to hypoxia. The CBS inhibitor attenuated the hypoxia-induced increase in the H2 S synthesis, suggesting an endogenous synthesis of the gas. CONCLUSION These data provide solid evidence that AVPO H2 S production is stimulated by hypoxia, and this gaseous messenger exerts an inhibitory modulation of the hypoxic ventilatory response. It is probable that the H2 S modulation of hypoxia-induced hyperventilation is at least in part in proportion to metabolism.
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Affiliation(s)
- M. Kwiatkoski
- Medical School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
| | - R. N. Soriano
- Nursing School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
- Dental School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
| | - G. S. F. da Silva
- Dental School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
| | - H. D. Francescato
- Medical School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
| | - T. M. Coimbra
- Medical School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
| | - M. L. Glass
- Medical School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
| | - E. C. Carnio
- Nursing School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
| | - L. G. S. Branco
- Dental School of Ribeirão Preto; University of São Paulo; Ribeirão Preto SP Brazil
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Olson JM, Jinka TR, Larson LK, Danielson JJ, Moore JT, Carpluck J, Drew KL. Circannual rhythm in body temperature, torpor, and sensitivity to A₁ adenosine receptor agonist in arctic ground squirrels. J Biol Rhythms 2013; 28:201-7. [PMID: 23735499 DOI: 10.1177/0748730413490667] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A₁ adenosine receptor (A₁AR) activation within the central nervous system induces torpor, but in obligate hibernators such as the arctic ground squirrel (AGS; Urocitellus parryii), A₁AR stimulation induces torpor only during the hibernation season, suggesting a seasonal increase in sensitivity to A₁AR signaling. The purpose of this research was to investigate the relationship between body temperature (Tb) and sensitivity to an adenosine A1 receptor agonist in AGS. We tested the hypothesis that increased sensitivity in A₁AR signaling would lead to lower Tb in euthermic animals during the hibernation season when compared with the summer season. We further predicted that if a decrease in euthermic Tb reflects increased sensitivity to A₁AR activation, then it should likewise predict spontaneous torpor. We used subcutaneous IPTT-300 transponders to monitor Tb in AGS housed under constant ambient conditions (12:12 L:D, 18 °C) for up to 16 months. These animals displayed an obvious rhythm in euthermic Tb that cycled with a period of approximately 8 months. Synchrony in the Tb rhythm within the group was lost after several months of constant L:D conditions; however, individual rhythms in Tb continued to show clear sine wave-like waxing and waning. AGS displayed spontaneous torpor only during troughs in euthermic Tb. To assess sensitivity to A₁AR activation, AGS were administered the A₁AR agonist N(6)-cyclohexyladenosine (CHA, 0.1 mg/kg, ip), and subcutaneous Tb was monitored. AGS administered CHA during a seasonal minimum in euthermic Tb showed a greater drug-induced decrease in Tb (1.6 ± 0.3 °C) than did AGS administered CHA during a peak in euthermic Tb (0.4 ± 0.3 °C). These results provide evidence for a circannual rhythm in Tb that is associated with increased sensitivity to A₁AR signaling and correlates with the onset of torpor.
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Affiliation(s)
- Jasmine M Olson
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775-7000, USA
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16
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ATP induces mild hypothermia in rats but has a strikingly detrimental impact on focal cerebral ischemia. J Cereb Blood Flow Metab 2013; 33:jcbfm2012146. [PMID: 23072747 PMCID: PMC3597371 DOI: 10.1038/jcbfm.2012.146] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ischemic stroke is a devastating condition lacking effective therapies. A promising approach to attenuate ischemic injury is mild hypothermia. Recent studies show that adenosine nucleotides can induce hypothermia in mice. The purpose of the present study was to test the hypothesis that adenosine 5'-triphosphate (ATP) induces mild hypothermia in rats and reduces ischemic brain injury. We found that intraperitoneal injections of ATP decreased core body temperature in a dose-dependent manner; the dose appropriate for mild hypothermia was 2 g/kg. When ATP-induced hypothermia was applied to stroke induced by middle cerebral artery occlusion, however, a neuroprotective effect was not observed. Instead, the infarct volume grew even larger in ATP-treated rats. This was accompanied by an increased rate of seizure events, hemorrhagic transformation, and higher mortality. Continuous monitoring of physiologic parameters revealed that ATP reduced heartbeat rate and blood pressure. ATP also increased blood glucose, accompanied by severe acidosis and hypocalcemia. Western blotting showed that ATP decreased levels of both phospho-Akt and total-Akt in the cortex. Our results reveal that, despite inducing hypothermia, ATP is not appropriate for protecting the brain against stroke. Instead, we show for the first time that ATP treatment is associated with exaggerated ischemic outcomes and dangerous systemic side effects.
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17
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Kermanian F, Mehdizadeh M, Soleimani M, Ebrahimzadeh Bideskan AR, Asadi-Shekaari M, Kheradmand H, Haghir H. The role of adenosine receptor agonist and antagonist on Hippocampal MDMA detrimental effects; a structural and behavioral study. Metab Brain Dis 2012; 27:459-69. [PMID: 22961480 DOI: 10.1007/s11011-012-9334-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 08/28/2012] [Indexed: 11/28/2022]
Abstract
There is abundant evidence showing that repeated use of MDMA (3, 4-Methylenedioxymethamphetamine, ecstasy) has been associated with depression, anxiety and deficits in learning and memory, suggesting detrimental effects on hippocampus. Adenosine is an endogenous purine nucleoside that has a neuromodulatory role in the central nervous system. In the present study, we investigated the role of A2a adenosine receptors agonist (CGS) and antagonist (SCH) on the body temperature, learning deficits, and hippocampal cell death induced by MDMA administration. In this study, 63 adult, male, Sprague - Dawley rats were subjected to MDMA (10 and 20 mg/kg) followed by intraperitoneal CGS (0.03 mg/kg) or SCH (0.03 mg/kg) injection. The animals were tested for spatial learning in the Morris water maze (MWM) task performance, accompanied by a recording of body temperature, electron microscopy and stereological study. Our results showed that MDMA treatment increased body temperature significantly, and impaired the ability of rats to locate the hidden platform(P < 0.05). The number of hippocampal dark neurons also increased especially in CA1. These impairments were aggravated by co-administration of A2a antagonist (SCH) with MDMA. Furthermore, the administration of the A2a receptor agonist (CGS) provided partial protection against MWM deficits and hippocampal cell death(P < 0.05). This study provides for the first time evidence that, in contrast to A2a antagonist (SCH) effects, co-administration of A2a agonist (CGS) with MDMA can protect against MDMA hippocampal neurotoxic effects; providing a potential value in the prevention of learning deficits observed in MDMA users. However, the exact mechanism of these interactions requires further studies.
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Affiliation(s)
- Fatemeh Kermanian
- Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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Kwiatkoski M, Soriano RN, Francescato HDC, Batalhao ME, Coimbra TM, Carnio EC, Branco LGS. Hydrogen sulfide as a cryogenic mediator of hypoxia-induced anapyrexia. Neuroscience 2011; 201:146-56. [PMID: 22120434 DOI: 10.1016/j.neuroscience.2011.11.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 11/09/2011] [Accepted: 11/10/2011] [Indexed: 12/29/2022]
Abstract
Hypoxia causes a regulated decrease in body temperature (Tb), a response that has been aptly called anapyrexia, but the mechanisms involved are not completely understood. The roles played by nitric oxide (NO) and other neurotransmitters have been documented during hypoxia-induced anapyrexia, but no information exists with respect to hydrogen sulfide (H(2)S), a gaseous molecule endogenously produced by cystathionine β-synthase (CBS). We tested the hypothesis that H(2)S production is enhanced during hypoxia and that the gas acts in the anteroventral preoptic region (AVPO; the most important thermosensitive and thermointegrative region of the CNS) modulating hypoxia-induced anapyrexia. Thus, we assessed CBS and nitric oxide synthase (NOS) activities [by means of H(2)S and nitrite/nitrate (NO(x)) production, respectively] as well as cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-monophosphate (cGMP) levels in the anteroventral third ventricle region (AV3V; where the AVPO is located) during normoxia and hypoxia. Furthermore, we evaluated the effects of pharmacological modifiers of the H(2)S pathway given i.c.v. or intra-AVPO. I.c.v. or intra-AVPO microinjection of CBS inhibitor caused no change in Tb under normoxia but significantly attenuated hypoxia-induced anapyrexia. During hypoxia there were concurrent increases in H(2)S production, which could be prevented by CBS inhibitor, indicating the endogenous source of the gas. cAMP concentration, but not cGMP and NO(x), correlated with CBS activity. CBS inhibition increased NOS activity, whereas H(2)S donor decreased NO(x) production. In conclusion, hypoxia activates H(2)S endogenous production through the CBS-H(2)S pathway in the AVPO, having a cryogenic effect. Moreover, the present data are consistent with the notion that the two gaseous molecules, H(2)S and NO, play a key role in mediating the drop in Tb caused by hypoxia and that a fine-balanced interplay between NOS-NO and CBS-H(2)S pathways takes place in the AVPO of rats exposed to hypoxia.
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Affiliation(s)
- M Kwiatkoski
- Medical School of Ribeirão Preto, 14049-900, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Season primes the brain in an arctic hibernator to facilitate entrance into torpor mediated by adenosine A(1) receptors. J Neurosci 2011; 31:10752-8. [PMID: 21795527 DOI: 10.1523/jneurosci.1240-11.2011] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Torpor in hibernating mammals defines the nadir in mammalian metabolic demand and body temperature that accommodates seasonal periods of reduced energy availability. The mechanism of metabolic suppression during torpor onset is unknown, although the CNS is a key regulator of torpor. Seasonal hibernators, such as the arctic ground squirrel (AGS), display torpor only during the winter, hibernation season. The seasonal character of hibernation thus provides a clue to its regulation. In the present study, we delivered adenosine receptor agonists and antagonists into the lateral ventricle of AGSs at different times of the year while monitoring the rate of O(2) consumption and core body temperature as indicators of torpor. The A(1) antagonist cyclopentyltheophylline reversed spontaneous entrance into torpor. The adenosine A(1) receptor agonist N(6)-cyclohexyladenosine (CHA) induced torpor in six of six AGSs tested during the mid-hibernation season, two of six AGSs tested early in the hibernation season, and none of the six AGSs tested during the summer, off-season. CHA-induced torpor within the hibernation season was specific to A(1)AR activation; the A(3)AR agonist 2-Cl-IB MECA failed to induce torpor, and the A(2a)R antagonist MSX-3 failed to reverse spontaneous onset of torpor. CHA-induced torpor was similar to spontaneous entrance into torpor. These results show that metabolic suppression during torpor onset is regulated within the CNS via A(1)AR activation and requires a seasonal switch in the sensitivity of purinergic signaling.
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Osaka T. Hypoxia-induced hypothermia mediated by noradrenaline and nitric oxide in the rostromedial preoptic area. Neuroscience 2011; 179:170-8. [DOI: 10.1016/j.neuroscience.2011.01.056] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 01/09/2011] [Accepted: 01/24/2011] [Indexed: 10/18/2022]
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Ruiz-Medina J, Ledent C, Carretón O, Valverde O. The A2a adenosine receptor modulates the reinforcement efficacy and neurotoxicity of MDMA. J Psychopharmacol 2011; 25:550-64. [PMID: 21262860 DOI: 10.1177/0269881110389210] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Adenosine is an endogenous purine nucleoside that plays a neuromodulatory role in the central nervous system. A2a adenosine receptors have been involved in reward-related processes, inflammatory phenomena and neurotoxicity reactions. In the present study, we investigated the role of A2a adenosine receptors on the acute pharmacological effects, reinforcement and neuroinflammation induced by MDMA administration. First, the acute effects of MDMA on body temperature, locomotor activity and anxiety-like responses were measured in A2a knockout mice and wild-type littermates. Second, MDMA reinforcing properties were evaluated using the intravenous self-administration paradigm. Finally, we assessed striatal astrogliosis and microgliosis as markers of MDMA neurotoxicity. Our results showed that acute MDMA produced a biphasic effect on body temperature and increased locomotor activity and anxiogenic-like responses in both genotypes. However, MDMA reinforcing properties were dramatically affected by the lack of A2a adenosine receptors. Thus, wild-type mice maintained MDMA self-administration under a fixed ratio 1 reinforcement schedule, whereas the operant response appeared completely abolished in A2a knockout mice. In addition, the MDMA neurotoxic regime produced an enhanced inflammatory response in striatum of wild-type mice, revealed by a significant increase in glial expression, whereas such activation was attenuated in mutant mice. This is the first report indicating that A2a adenosine receptors play a key role in reinforcement and neuroinflammation induced by the widely used psychostimulant.
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Affiliation(s)
- Jessica Ruiz-Medina
- Grup de Recerca en Neurobiologia del Comportament (GRNC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
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22
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Fredholm BB, Johansson S, Wang YQ. Adenosine and the Regulation of Metabolism and Body Temperature. ADVANCES IN PHARMACOLOGY 2011; 61:77-94. [DOI: 10.1016/b978-0-12-385526-8.00003-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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23
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Jinka TR, Carlson ZA, Moore JT, Drew KL. Altered thermoregulation via sensitization of A1 adenosine receptors in dietary-restricted rats. Psychopharmacology (Berl) 2010; 209:217-24. [PMID: 20186398 PMCID: PMC2892230 DOI: 10.1007/s00213-010-1778-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 01/04/2010] [Indexed: 11/30/2022]
Abstract
RATIONALE Evidence links longevity to dietary restriction (DR). A decrease in body temperature (T(b)) is thought to contribute to enhanced longevity because lower T(b) reduces oxidative metabolism and oxidative stress. It is as yet unclear how DR decreases T(b). OBJECTIVE Here, we test the hypothesis that prolonged DR decreases T(b) by sensitizing adenosine A(1) receptors (A(1)AR) and adenosine-induced cooling. METHODS AND RESULTS Sprague-Dawley rats were dietary restricted using an every-other-day feeding protocol. Rats were fed every other day for 27 days and then administered the A(1)AR agonist, N(6)-cyclohexyladenosine (CHA; 0.5 mg/kg, i.p.). Respiratory rate (RR) and subcutaneous T(b) measured using IPTT-300 transponders were monitored every day and after drug administration. DR animals displayed lower RR on day 20 and lower T(b) on day 22 compared to animals fed ad libitum and displayed a larger response to CHA. In all cases, RR declined before T(b). Contrary to previous reports, a higher dose of CHA (5 mg/kg, i.p.) was lethal in both dietary groups. We next tested the hypothesis that sensitization to the effects of CHA was due to increased surface expression of A(1)AR within the hypothalamus. We report that the abundance of A(1)AR in the membrane fraction increases in hypothalamus, but not cortex of DR rats. CONCLUSION These results suggest that every-other-day feeding lowers T(b) via sensitization of thermoregulatory effects of endogenous adenosine by increasing surface expression of A(1)AR. DISCUSSION Evidence that diet can modulate purinergic signaling has implications for the treatment of stroke, brain injury, epilepsy, and aging.
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Icaza EE, Huang X, Fu Y, Neubig RR, Baghdoyan HA, Lydic R. Isoflurane-induced changes in righting response and breathing are modulated by RGS proteins. Anesth Analg 2009; 109:1500-5. [PMID: 19843788 DOI: 10.1213/ane.0b013e3181ba7815] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Recent evidence suggests that G protein-coupled receptors, especially those linked to G(alpha)(i), contribute to the mechanisms of anesthetic action. Regulator of G protein signaling (RGS) proteins bind to activated G(alpha)(i) and inhibit signal transduction. Genomic knock-in mice with an RGS-insensitive G(alpha)(i2) G184S (G(alpha)(i2) GS) allele exhibit enhanced G(alpha)(i2) signaling and provide a novel approach for investigating the role of G(alpha)(i2) signaling and RGS proteins in general anesthesia. METHODS We anesthetized homozygous G(alpha)(i2) GS/GS and wild-type (WT) mice with isoflurane and quantified time (in seconds) to loss and resumption of righting response. During recovery from isoflurane anesthesia, breathing was quantified in a plethysmography chamber for both lines of mice. RESULTS G(alpha)(i2) GS/GS mice required significantly less time for loss of righting and significantly more time for resumption of righting than WT mice. During recovery from isoflurane anesthesia, G(alpha)(i2) GS/GS mice exhibited significantly greater respiratory depression. Poincaré analyses show that GS/GS mice have diminished respiratory variability compared with WT mice. CONCLUSION Modulation of G(alpha)(i2) signaling by RGS proteins alters loss and resumption of wakefulness and state-dependent changes in breathing.
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Affiliation(s)
- Eduardo E Icaza
- Departments of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109-5615, USA
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25
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Yang JN, Chen JF, Fredholm BB. Physiological roles of A1 and A2A adenosine receptors in regulating heart rate, body temperature, and locomotion as revealed using knockout mice and caffeine. Am J Physiol Heart Circ Physiol 2009; 296:H1141-9. [PMID: 19218506 DOI: 10.1152/ajpheart.00754.2008] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heart rate (HR), body temperature (Temp), locomotor activity (LA), and oxygen consumption (O(2)C) were studied in awake mice lacking one or both of the adenosine A(1) or A(2A) receptors (A(1)R or A(2A)R, respectively) using telemetry and respirometry, before and after caffeine administration. All parameters were lower during day than night and higher in females than males. When compared with wild-type (WT) littermates, HR was higher in male A(1)R knockout (A(1)RKO) mice but lower in A(2A)RKO mice and intermediate in A(1)-A(2A)R double KO mice. A single dose of an unselective beta-blocker (timolol; 1 mg/kg) abolished the HR differences between these genotypes. Deletion of A(1)Rs had little effect on Temp, whereas deletion of A(2A)Rs increased it in females and decreased it in males. A(1)-A(2A)RKO mice had lower Temp than WT mice. LA was unaltered in A(1)RKO mice and lower in A(2A)RKO and A(1)-A(2A)RKO mice than in WT mice. Caffeine injection increased LA but only in mice expressing A(2A)R. Caffeine ingestion also increased LA in an A(2A)R-dependent manner in male mice. Caffeine ingestion significantly increased O(2)C in WT mice, but less in the different KO mice. Injection of 30 mg/kg caffeine decreased Temp, especially in KO mice, and hence in a manner unrelated to A(1)R or A(2A)R blockade. Selective A(2B) antagonism had little or no effect. Thus A(1)R and A(2A)R influence HR, Temp, LA, and O(2)C in mice in a sex-dependent manner, indicating effects of endogenous adenosine. The A(2A)R plays an important role in the modulation of O(2)C and LA by acute and chronic caffeine administration. There is also evidence for effects of higher doses of caffeine being independent of both A(1)R and A(2A)R.
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Affiliation(s)
- Jiang-Ning Yang
- Karolinska Institutet, Nanna Svartz väg 2, Stockholm S-171 77 Sweden.
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Nathaniel TI. Brain-regulated metabolic suppression during hibernation: a neuroprotective mechanism for perinatal hypoxia-ischemia. Int J Stroke 2008; 3:98-104. [PMID: 18706003 DOI: 10.1111/j.1747-4949.2008.00186.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hypoxic-ischemic brain injury in the perinatal period is a major cause of chronic disability and acute mortality in newborns. Despite numerous therapeutic strategies that reduce hypoxia-ischemia-induced damage in different experimental animal models, most of them have failed to translate to clinical therapies. This challenge calls for an urgent need to explore novel approaches to develop effective therapies for the clinical management of perinatal hypoxia-ischemia brain injury. This review focuses on studies that investigate neuroprotective related events during mammalian hibernation, characterized by dramatic reductions in several parameters including body temperature, oxygen consumption and heart rate, such that it is difficult to tell if the hibernating animal is dead or alive. The first part of this article reviews the mechanisms of metabolic suppression related events during hibernation. In the second part, hypoxic-ischemic events in the perinatal brain are discussed, and in turn, contrasted with brains experiencing metabolic suppression during mammalian hibernation. In the last part of this article, the diverse neuroprotective adaptations of hibernators and the mechanisms that might be involved in mammalian hibernation, and how they could in turn, contribute to neurprotection during perinatal hypoxia-ischemia related injuries are discussed. This article appraises the novel idea that knowledge of the central mechanisms involved in the regulatory metabolic suppression, during which; hibernators switch themselves off without dissolving their brains could represent brain neuroprotective strategy for the clinical management of perinatal hypoxia-ischemia brain injuries in newborns.
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Affiliation(s)
- Thomas I Nathaniel
- Center for Natural and Health Sciences, Marywood University, 2300 Adams Avenue, Scranton, PA 18509, USA.
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Scott GR, Cadena V, Tattersall GJ, Milsom WK. Body temperature depression and peripheral heat loss accompany the metabolic and ventilatory responses to hypoxia in low and high altitude birds. J Exp Biol 2008; 211:1326-35. [DOI: 10.1242/jeb.015958] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe objectives of this study were to compare the thermoregulatory,metabolic and ventilatory responses to hypoxia of the high altitude bar-headed goose with low altitude waterfowl. All birds were found to reduce body temperature (Tb) during hypoxia, by up to 1–1.5°C in severe hypoxia. During prolonged hypoxia, Tb stabilized at a new lower temperature. A regulated increase in heat loss contributed to Tb depression as reflected by increases in bill surface temperatures (up to 5°C) during hypoxia. Bill warming required peripheral chemoreceptor inputs, since vagotomy abolished this response to hypoxia. Tb depression could still occur without bill warming, however, because vagotomized birds reduced Tb as much as intact birds. Compared to both greylag geese and pekin ducks, bar-headed geese required more severe hypoxia to initiate Tb depression and heat loss from the bill. However, when Tb depression or bill warming were expressed relative to arterial O2 concentration (rather than inspired O2) all species were similar; this suggests that enhanced O2 loading,rather than differences in thermoregulatory control centres, reduces Tb depression during hypoxia in bar-headed geese. Correspondingly, bar-headed geese maintained higher rates of metabolism during severe hypoxia (7% inspired O2), but this was only partly due to differences in Tb. Time domains of the hypoxic ventilatory response also appeared to differ between bar-headed geese and low altitude species. Overall, our results suggest that birds can adjust peripheral heat dissipation to facilitate Tb depression during hypoxia,and that bar-headed geese minimize Tb and metabolic depression as a result of evolutionary adaptations that enhance O2transport.
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Affiliation(s)
- Graham R. Scott
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4,Canada
| | - Viviana Cadena
- Department of Biological Sciences, Brock University, St Catherines, ON, L25 3A1, Canada
| | - Glenn J. Tattersall
- Department of Biological Sciences, Brock University, St Catherines, ON, L25 3A1, Canada
| | - William K. Milsom
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4,Canada
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Nishii Y, Okada Y, Yokoba M, Katagiri M, Yanaihara T, Masuda N, Easton P, Abe T. Aminophylline increases parasternal intercostal muscle activity during hypoxia in humans. Respir Physiol Neurobiol 2008; 161:69-75. [DOI: 10.1016/j.resp.2007.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 12/13/2007] [Accepted: 12/15/2007] [Indexed: 11/25/2022]
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Drew KL, Buck CL, Barnes BM, Christian SL, Rasley BT, Harris MB. Central nervous system regulation of mammalian hibernation: implications for metabolic suppression and ischemia tolerance. J Neurochem 2007; 102:1713-1726. [PMID: 17555547 PMCID: PMC3600610 DOI: 10.1111/j.1471-4159.2007.04675.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Torpor during hibernation defines the nadir of mammalian metabolism where whole animal rates of metabolism are decreased to as low as 2% of basal metabolic rate. This capacity to decrease profoundly the metabolic demand of organs and tissues has the potential to translate into novel therapies for the treatment of ischemia associated with stroke, cardiac arrest or trauma where delivery of oxygen and nutrients fails to meet demand. If metabolic demand could be arrested in a regulated way, cell and tissue injury could be attenuated. Metabolic suppression achieved during hibernation is regulated, in part, by the central nervous system through indirect and possibly direct means. In this study, we review recent evidence for mechanisms of central nervous system control of torpor in hibernating rodents including evidence of a permissive, hibernation protein complex, a role for A1 adenosine receptors, mu opiate receptors, glutamate and thyrotropin-releasing hormone. Central sites for regulation of torpor include the hippocampus, hypothalamus and nuclei of the autonomic nervous system. In addition, we discuss evidence that hibernation phenotypes can be translated to non-hibernating species by H(2)S and 3-iodothyronamine with the caveat that the hypothermia, bradycardia, and metabolic suppression induced by these compounds may or may not be identical to mechanisms employed in true hibernation.
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Affiliation(s)
- Kelly L. Drew
- Institute of Arctic Biology, Alaska Basic Neuroscience Program, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- Department of Chemistry and Biochemistry, Alaska Basic Neuroscience Program, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - C. Loren Buck
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, Alaska, USA
| | - Brian M. Barnes
- Institute of Arctic Biology, Alaska Basic Neuroscience Program, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Sherri L. Christian
- Institute of Arctic Biology, Alaska Basic Neuroscience Program, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Brian T. Rasley
- Department of Chemistry and Biochemistry, Alaska Basic Neuroscience Program, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Michael B. Harris
- Institute of Arctic Biology, Alaska Basic Neuroscience Program, University of Alaska Fairbanks, Fairbanks, Alaska, USA
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Scott GR, Milsom WK. Control of breathing and adaptation to high altitude in the bar-headed goose. Am J Physiol Regul Integr Comp Physiol 2007; 293:R379-91. [PMID: 17491113 DOI: 10.1152/ajpregu.00161.2007] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The bar-headed goose flies over the Himalayan mountains on its migratory route between South and Central Asia, reaching altitudes of up to 9,000 m. We compared control of breathing in this species with that of low-altitude waterfowl by exposing birds to step decreases in inspired O(2) under both poikilocapnic and isocapnic conditions. Bar-headed geese breathed substantially more than both greylag geese and pekin ducks during severe environmental (poikilocapnic) hypoxia (5% inspired O(2)). This was entirely due to an enhanced tidal volume response to hypoxia, which would have further improved parabronchial (effective) ventilation. Consequently, O(2) loading into the blood and arterial Po(2) were substantially improved. Because air convection requirements were similar between species at 5% inspired O(2), it was the enhanced tidal volume response (not total ventilation per se) that improved O(2) loading in bar-headed geese. Other observations suggest that bar-headed geese depress metabolism less than low-altitude birds during hypoxia and also may be capable of generating higher inspiratory airflows. There were no differences between species in ventilatory sensitivities to isocapnic hypoxia, the hypoxia-induced changes in blood CO(2) tensions or pH, or hypercapnic ventilatory sensitivities. Overall, our results suggest that evolutionary changes in the respiratory control system of bar-headed geese enhance O(2) loading into the blood and may contribute to this species' exceptional ability to fly high.
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Affiliation(s)
- Graham R Scott
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada.
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Comparison of NMDA modulation of breathing and NR1 expression in medullary nuclei of weanling male and female rats. Respir Physiol Neurobiol 2007; 155:203-12. [DOI: 10.1016/j.resp.2006.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Revised: 06/13/2006] [Accepted: 06/21/2006] [Indexed: 11/20/2022]
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