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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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Guo M, Wang J, Yuan Y, Chen L, He J, Wei W, Xu F, Liu Q, Peng M. Role of adenosine A 2A receptors in the loss of consciousness induced by propofol anesthesia. J Neurochem 2023; 164:684-699. [PMID: 36445101 DOI: 10.1111/jnc.15734] [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: 09/17/2022] [Revised: 11/09/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022]
Abstract
The mechanism of propofol-anesthesia-induced loss of consciousness (LOC) remains largely unknown. We speculated that the adenosine A2A receptor serves as a vital molecular target in regulating LOC states under propofol anesthesia. c-Fos staining helped observe the changes in the neuronal activity in the nucleus accumbens (NAc). Initially, the adenosine signals in the NAc were measured under propofol anesthesia using fiber photometry recordings. Then, behavior tests and electrophysiological recordings were used to verify the effect of systemic A2A R agonist or antagonist treatment on propofol anesthesia. Next, the microinjection technique was used to clarify the role of the NAc A2A R under propofol anesthesia. Fiber photometry recordings were applied to assess the effect of A2A R agonist or antagonist systemic treatment on adenosine signal alterations in the NAc during propofol anesthesia. Then, as the GABAergic neurons are the main neurons in the NAc, we further measured the neuronal activity of GABAergic neurons. In our study, propofol anesthesia enhanced the neuronal activity in the NAc, and the adenosine signals were increased in the NAc. SCH58261 reduced the LOC time and sedative depth, while CGS21680 increased those via intraperitoneal injection. Additionally, CGS21680 increased the changes in delta, theta, alpha, beta, and low-gamma oscillations in the NAc. Moreover, microinjection of SCH58261 significantly shortened the LOC time, whereas microinjection of CGS21680 into the NAc significantly prolonged the LOC duration. The results illustrated that after A2A R agonist administration, the level of extracellular adenosine signals in the NAc was decreased and the neuronal activity of GABAergic neurons was enhanced, whereas after A2A R antagonist administration via intraperitoneal injection, the opposite occurred. This study reveals the vital role of the A2A R in propofol-induced LOC and that the A2A R could affect the maintenance of propofol anesthesia.
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Affiliation(s)
- Meimei Guo
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Jie Wang
- Institute of Neuroscience and Brain Disease, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, Hubei Province, China.,State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan, Hubei Province, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yikang Yuan
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Lei Chen
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China.,Department of Anesthesiology, Peking University Third Hospital, Beijing, China
| | - Jingang He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan, Hubei Province, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wei Wei
- Brain Research Center, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China.,Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Fuqiang Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan, Hubei Province, China.,University of Chinese Academy of Sciences, Beijing, China.,The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Key Laboratory of Viral Vectors for Biomedicine, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Qing Liu
- University of Chinese Academy of Sciences, Beijing, China.,The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Key Laboratory of Viral Vectors for Biomedicine, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Mian Peng
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China.,Brain Research Center, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China
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Cellai L, Carvalho K, Faivre E, Deleau A, Vieau D, Buée L, Blum D, Mériaux C, Gomez-Murcia V. The Adenosinergic Signaling: A Complex but Promising Therapeutic Target for Alzheimer's Disease. Front Neurosci 2018; 12:520. [PMID: 30123104 PMCID: PMC6085480 DOI: 10.3389/fnins.2018.00520] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/11/2018] [Indexed: 01/02/2023] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disorder in elderly people. AD is characterized by a progressive cognitive decline and it is neuropathologically defined by two hallmarks: extracellular deposits of aggregated β-amyloid (Aβ) peptides and intraneuronal fibrillar aggregates of hyper- and abnormally phosphorylated Tau proteins. AD results from multiple genetic and environmental risk factors. Epidemiological studies reported beneficial effects of caffeine, a non-selective adenosine receptors antagonist. In the present review, we discuss the impact of caffeine and of adenosinergic system modulation on AD, in terms of pathology and therapeutics.
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Affiliation(s)
- Lucrezia Cellai
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - Kevin Carvalho
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - Emilie Faivre
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - Aude Deleau
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - Didier Vieau
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - Luc Buée
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - David Blum
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - Céline Mériaux
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
| | - Victoria Gomez-Murcia
- Institut National de la Santé et de la Recherche Médicale, CHU Lille, UMR-S 1172-JPArc, LabEx DISTALZ, Université de Lille, Lille, France
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Duggan DJ, Tabrizchi R. Angiotensin II control of regional haemodynamics in rats with aortocaval fistula. Exp Physiol 2016; 101:1192-1205. [PMID: 27427425 DOI: 10.1113/ep085717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 07/12/2016] [Indexed: 12/17/2022]
Abstract
NEW FINDINGS What is the central question of this study? Hyperdynamic circulation because of arteriovenous fistula results in reduction of blood flow to organs but is a model of low circulatory resistance with activated renin-angiotensin system. The aim was to determine contributions of different subtypes of angiotensin II receptors to regional blood flow and vascular conductance in a hyperdynamic circulatory state. What is the main finding and its importance? The renin-angiotensin system plays a pivotal role in control of regional blood flow in animals with arteriovenous fistula and makes a major contribution to the maintenance of normal arterial blood pressure. In this hyperdynamic circulatory state model, angiotensin II type 1 receptors predominated in regulating regional haemodynamics. Regional perfusion is reduced and the renin-angiotensin system activated in rats with aortocaval fistula. The effects of captopril (angiotensin-converting enzyme inhibitor), losartan (angiotensin II type 1 receptor antagonist) and PD 123319 (angiotensin II type 2 receptor antagonist) on regional blood flow and vascular conductance were assessed in rats with aortocaval fistula and sham-operated rats. Control of blood flow and vascular conductance by angiotensin II was evaluated by serial bolus injections of captopril, losartan and PD 123319 in anaesthetized rats. In rats with fistula, PD 123319 significantly decreased, whereas captopril and losartan increased, mesenteric blood flow. The decrease in mesenteric blood flow induced by PD 123319 was significantly greater in rats with fistula compared with sham operation. Captopril and PD 123319 significantly decreased renal blood flow compared with losartan, which increased it. In sham-operated rats, captopril and losartan significantly increased, whereas PD 123319 decreased, mesenteric and renal conductance. In rats with fistula, captopril and losartan significantly increased, whereas PD 123319 decreased, mesenteric conductance. The significant increase produced by losartan on mesenteric conductance was greater in rats with fistula compared with sham operation. PD 123319 produced a significantly greater decrease in renal conductance of rats with aortocaval fistula compared with sham-operated rats. Captopril, losartan and PD 123319 did not significantly affect perfusion in the hindquarter in rats with fistula or sham-operated. The renin-angiotensin system is more active in the control of regional haemodynamics in rats with aortocaval fistula and acts as a mechanism of maintaining normal arterial blood pressure in these animals. In rats with fistula, angiotensin II type 1 receptors predominate in regulating regional haemodynamics.
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Affiliation(s)
- Daniel J Duggan
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
| | - Reza Tabrizchi
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
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Kaur J, Spranger MD, Hammond RL, Krishnan AC, Alvarez A, Augustyniak RA, O'Leary DS. Muscle metaboreflex activation during dynamic exercise evokes epinephrine release resulting in β2-mediated vasodilation. Am J Physiol Heart Circ Physiol 2014; 308:H524-9. [PMID: 25539712 DOI: 10.1152/ajpheart.00648.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Muscle metaboreflex-induced increases in mean arterial pressure (MAP) during submaximal dynamic exercise are mediated principally by increases in cardiac output. To what extent, if any, the peripheral vasculature contributes to this rise in MAP is debatable. In several studies, we observed that in response to muscle metaboreflex activation (MMA; induced by partial hindlimb ischemia) a small but significant increase in vascular conductance occurred within the nonischemic areas (calculated as cardiac output minus hindlimb blood flow and termed nonischemic vascular conductance; NIVC). We hypothesized that these increases in NIVC may stem from a metaboreflex-induced release of epinephrine, resulting in β2-mediated dilation. We measured NIVC and arterial plasma epinephrine levels in chronically instrumented dogs during rest, mild exercise (3.2 km/h), and MMA before and after β-blockade (propranolol; 2 mg/kg), α1-blockade (prazosin; 50 μg/kg), and α1 + β-blockade. Both epinephrine and NIVC increased significantly from exercise to MMA: 81.9 ± 18.6 to 141.3 ± 22.8 pg/ml and 33.8 ± 1.5 to 37.6 ± 1.6 ml·min(-1)·mmHg(-1), respectively. These metaboreflex-induced increases in NIVC were abolished after β-blockade (27.6 ± 1.8 to 27.5 ± 1.7 ml·min(-1)·mmHg(-1)) and potentiated after α1-blockade (36.6 ± 2.0 to 49.7 ± 2.9 ml·min(-1)·mmHg(-1)), while α1 + β-blockade also abolished any vasodilation (33.7 ± 2.9 to 30.4 ± 1.9 ml·min(-1)·mmHg(-1)). We conclude that MMA during mild dynamic exercise induces epinephrine release causing β2-mediated vasodilation.
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Affiliation(s)
- Jasdeep Kaur
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
| | - Marty D Spranger
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
| | - Robert L Hammond
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
| | - Abhinav C Krishnan
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
| | - Alberto Alvarez
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
| | - Robert A Augustyniak
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
| | - Donal S O'Leary
- Department of Physiology and Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, Michigan
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Central activation of the A1 adenosine receptor (A1AR) induces a hypothermic, torpor-like state in the rat. J Neurosci 2013; 33:14512-25. [PMID: 24005302 DOI: 10.1523/jneurosci.1980-13.2013] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Since central activation of A1 adenosine receptors (A1ARs) plays an important role in the induction of the hypothermic and hypometabolic torpid state in hibernating mammals, we investigated the potential for the A1AR agonist N6-cyclohexyladenosine to induce a hypothermic, torpor-like state in the (nonhibernating) rat. Core and brown adipose tissue temperatures, EEG, heart rate, and arterial pressure were recorded in free-behaving rats, and c-fos expression in the brain was analyzed, following central administration of N6-cyclohexyladenosine. Additionally, we recorded the sympathetic nerve activity to brown adipose tissue; expiratory CO2 and skin, core, and brown adipose tissue temperatures; and shivering EMGs in anesthetized rats following central and localized, nucleus of the solitary tract, administration of N6-cyclohexyladenosine. In rats exposed to a cool (15°C) ambient temperature, central A1AR stimulation produced a torpor-like state similar to that in hibernating species and characterized by a marked fall in body temperature due to an inhibition of brown adipose tissue and shivering thermogenesis that is mediated by neurons in the nucleus of the solitary tract. During the induced hypothermia, EEG amplitude and heart rate were markedly reduced. Skipped heartbeats and transient bradycardias occurring during the hypothermia were vagally mediated since they were eliminated by systemic muscarinic receptor blockade. These findings demonstrate that a deeply hypothermic, torpor-like state can be pharmacologically induced in a nonhibernating mammal and that recovery of normothermic homeostasis ensues upon rewarming. These results support the potential for central activation of A1ARs to be used in the induction of a hypothermic, therapeutically beneficial state in humans.
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Ichinose TK, Minic Z, Li C, O'Leary DS, Scislo TJ. Activation of NTS A(1) adenosine receptors inhibits regional sympathetic responses evoked by activation of cardiopulmonary chemoreflex. Am J Physiol Regul Integr Comp Physiol 2012; 303:R539-50. [PMID: 22814665 DOI: 10.1152/ajpregu.00164.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previously we have shown that adenosine operating via the A(1) receptor subtype may inhibit glutamatergic transmission in the baroreflex arc within the nucleus of the solitary tract (NTS) and differentially increase renal (RSNA), preganglionic adrenal (pre-ASNA), and lumbar (LSNA) sympathetic nerve activity (ASNA>RSNA≥LSNA). Since the cardiopulmonary chemoreflex and the arterial baroreflex are mediated via similar medullary pathways, and glutamate is a primary transmitter in both pathways, it is likely that adenosine operating via A(1) receptors in the NTS may differentially inhibit regional sympathetic responses evoked by activation of cardiopulmonary chemoreceptors. Therefore, in urethane-chloralose-anesthetized rats (n = 37) we compared regional sympathoinhibition evoked by the cardiopulmonary chemoreflex (activated with right atrial injections of serotonin 5HT(3) receptor agonist phenylbiguanide, PBG, 1-8 μg/kg) before and after selective stimulation of NTS A(1) adenosine receptors [microinjections of N(6)-cyclopentyl adenosine (CPA), 0.033-330 pmol/50 nl]. Activation of cardiopulmonary chemoreceptors evoked differential, dose-dependent sympathoinhibition (RSNA>ASNA>LSNA), and decreases in arterial pressure and heart rate. These differential sympathetic responses were uniformly attenuated in dose-dependent manner by microinjections of CPA into the NTS. Volume control (n = 11) and blockade of adenosine receptor subtypes in the NTS via 8-(p-sulfophenyl)theophylline (8-SPT, 1 nmol in 100 nl) (n = 9) did not affect the reflex responses. We conclude that activation of NTS A(1) adenosine receptors uniformly inhibits neural and cardiovascular cardiopulmonary chemoreflex responses. A(1) adenosine receptors have no tonic modulatory effect on this reflex under normal conditions. However, when adenosine is released into the NTS (i.e., during stress or severe hypotension/ischemia), it may serve as negative feedback regulator for depressor and sympathoinhibitory reflexes integrated in the NTS.
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Affiliation(s)
- Tomoko K Ichinose
- Department of Physiology, Wayne State University School of Medicine Detroit, Detroit, MI 48201, USA
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Korim WS, Ferreira-Neto ML, Pedrino GR, Pilowsky PM, Cravo SL. Interaction of medullary P2 and glutamate receptors mediates the vasodilation in the hindlimb of rat. Purinergic Signal 2012; 8:715-28. [PMID: 22576313 DOI: 10.1007/s11302-012-9318-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 04/24/2012] [Indexed: 12/20/2022] Open
Abstract
In the nucleus tractus solitarii (NTS) of rats, blockade of extracellular ATP breakdown to adenosine reduces arterial blood pressure (AP) increases that follow stimulation of the hypothalamic defense area (HDA). The effects of ATP on NTS P2 receptors, during stimulation of the HDA, are still unclear. The aim of this study was to determine whether activation of P2 receptors in the NTS mediates cardiovascular responses to HDA stimulation. Further investigation was taken to establish if changes in hindlimb vascular conductance (HVC) elicited by electrical stimulation of the HDA, or activation of P2 receptors in the NTS, are relayed in the rostral ventrolateral medulla (RVLM); and if those responses depend on glutamate release by ATP acting on presynaptic terminals. In anesthetized and paralyzed rats, electrical stimulation of the HDA increased AP and HVC. Blockade of P2 or glutamate receptors in the NTS, with bilateral microinjections of suramin (10 mM) or kynurenate (50 mM) reduced only the evoked increase in HVC by 75 % or more. Similar results were obtained with the blockade combining both antagonists. Blockade of P2 and glutamate receptors in the RVLM also reduced the increases in HVC to stimulation of the HDA by up to 75 %. Bilateral microinjections of kynurenate in the RVLM abolished changes in AP and HVC to injections of the P2 receptor agonist α,β-methylene ATP (20 mM) into the NTS. The findings suggest that HDA-NTS-RVLM pathways in control of HVC are mediated by activation of P2 and glutamate receptors in the brainstem in alerting-defense reactions.
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Affiliation(s)
- Willian Seiji Korim
- Australian School of Advanced Medicine, Macquarie University, Sydney, Australia
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