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Mancuso C. Biliverdin as a disease-modifying agent: An integrated viewpoint. Free Radic Biol Med 2023; 207:133-143. [PMID: 37459935 DOI: 10.1016/j.freeradbiomed.2023.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/27/2023] [Accepted: 07/14/2023] [Indexed: 07/24/2023]
Abstract
Biliverdin is one of the three by-products of heme oxygenase (HO) activity, the others being ferrous iron and carbon monoxide. Under physiological conditions, once formed in the cell, BV is reduced to bilirubin (BR) by the biliverdin reductase (BVR). However, if BVR is inhibited by either genetic variants, as occurs in the Inuit ethnicity, or dioxin intoxication, BV accumulates in cells giving rise to a clinical syndrome known as green jaundice. Preclinical studies have demonstrated that BV not only has a direct antioxidant effect by scavenging free radicals, but also targets many signal transduction pathways, such as BVR, soluble guanylyl cyclase, and the aryl hydrocarbon receptor. Through these direct and indirect mechanisms, BV has shown beneficial roles in ischemia/reperfusion-related diseases, inflammatory diseases, graft-versus-host disease, viral infections and cancer. Unfortunately, no clinical data are available to confirm these potential therapeutic effects and the kinetics of exogenous BV in humans is unknown. These limitations have so far excluded the possibility of transforming BV from a mere by-product of heme degradation into a disease-modifying agent. A closer collaboration between basic and clinical researchers would be advantageous to overcome these issues and promote translational research on BV in free radical-induced diseases.
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Affiliation(s)
- Cesare Mancuso
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Department of Healthcare Surveillance and Bioethics, Section of Pharmacology, Università Cattolica Del Sacro Cuore, Largo F. Vito, 1, 00168, Rome, Italy.
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Amorim MR, Foresti R, Benrahla DE, Motterlini R, Branco LGS. CORM-401, an orally active carbon monoxide-releasing molecule, increases body temperature by activating non-shivering thermogenesis in rats. Temperature (Austin) 2022; 9:310-317. [PMID: 36339088 PMCID: PMC9629103 DOI: 10.1080/23328940.2022.2061270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Thermoregulation is critical in health and disease and is tightly controlled to maintain body temperature homeostasis. Carbon monoxide (CO), an endogenous gasotransmitter produced during heme degradation by heme oxygenases, has been suggested to play a role in body core temperature (Tb) regulation. However, a direct involvement of CO in thermoregulation has not been confirmed and its mechanism(s) of action remain largely unknown. In the present study we characterized the effects of systemic delivery of CO by administration of an orally active CO-releasing molecule (CORM-401) on Tb regulation in conscious freely moving rats. Specifically, we evaluated the main thermo effectors in rats treated with CORM-401 by assessing: (i) non-shivering thermogenesis, i.e. the increased metabolism of brown fat measured through oxygen consumption and (ii) the rate of heat loss from the tail through calculations of heat loss index. We found that oral administration of CORM-401 (30 mg/kg) resulted in augmented CO delivery into the blood circulation as evidenced a by significant increase in carbon monoxy hemoglobin levels(COHb). In addition, treatment with CORM-401 increased Tb, which was caused by an elevated non-shivering thermogenesis indicated by increased oxygen consumption without significant changes in the tail heat loss. On the other hand, CORM-401 did not affect blood pressure, but significantly decreased heart rate. In summary, the findings of the present study reveal that increased circulating CO levels lead to a rise in Tb, which could have important implications in the emerging role of CO in the modulation of energetic metabolism.
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Affiliation(s)
- Mateus R. Amorim
- Dental School of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Roberta Foresti
- Faculty of Health, University Paris Est Créteil, INSERM, IMRB, Créteil, France
| | | | - Roberto Motterlini
- Faculty of Health, University Paris Est Créteil, INSERM, IMRB, Créteil, France
| | - Luiz G. S. Branco
- Dental School of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
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Mancuso C. The brain heme oxygenase/biliverdin reductase system as a target in drug research and development. Expert Opin Ther Targets 2022; 26:361-374. [PMID: 35285395 DOI: 10.1080/14728222.2022.2052848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION The heme oxygenase/biliverdin reductase (HO/BVR) system is involved in heme metabolism. The inducible isoform of HO (HO-1) and BVR both exert cytoprotective effects by enhancing cell stress response. In this context, some xenobiotics, which target HO-1, including herbal products, behave as neuroprotectants in several experimental models of neurodegeneration. Despite this, no drug having either HO-1 or BVR as a main target is currently available. AREAS COVERED After a description of the brain HO/BVR system, the paper analyzes the main classes of drugs acting on the nervous system, with HO as second-level target, and their neuroprotective potential. Finally, the difficulties that exist for the development of drugs acting on HO/BVR and the possible ways to overcome these hurdles are examined. EXPERT OPINION Although the limited clinical evidence has restricted the translational research on the HO/BVR system, mainly because of the dual nature of its by-products, there has been growing interest in the therapeutic potential of these enzymes. Scientists should boost the translational research on the HO/BVR system which could be supported by the significant evidence provided by preclinical studies.
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Affiliation(s)
- Cesare Mancuso
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Healthcare Surveillance and Bioethics, Section of Pharmacology, Università Cattolica del Sacro Cuore, Rome, Italy
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Liu J, Lu W, Lu X, Zhang L, Dong H, Li Y. Versatile Ti 3C 2T x MXene for free-radical scavenging. NANO RESEARCH 2022; 15:2558-2566. [PMID: 34518776 PMCID: PMC8427154 DOI: 10.1007/s12274-021-3751-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 05/04/2023]
Abstract
UNLABELLED MXene, as an emerging two-dimensional (2D) material with ultrathin structure and fascinating physiochemical properties, has been widely explored in broad applications. Versatile functions of MXenes are continuously explored. This work presents distinctive feature of MXene-Ti3C2T x nanosheets for free-radical (FRs) scavenging that never reported before. We demonstrated the mechanism and equation in regard to the reaction between Ti3C2T x and H2O2, which was applied to design colorimetric H2O2 strip assay with good performance. The good FRs scavenging capability of Ti3C2T x , including a series of reactive oxygen species (ROS) and reactive nitrogen species (RNS), was systemically confirmed. The antioxidation capability of Ti3C2T x for protecting cells from oxidative damage was demonstrated using the oxidative damage model of alpha mouse liver 12 (AML-12) cells. This original work provides huge opportunities for MXenes in FR-related biomedical applications. ELECTRONIC SUPPLEMENTARY MATERIAL Supplementary material (further details of the experimental procedures, investigation of the reaction between Ti3C2T x and other oxidants, the characterization of endocytosis of cells for Ti3C2T x , and the comparison of different antioxidants for scavenging free radicals) is available in the online version of this article at 10.1007/s12274-021-3751-y.
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Affiliation(s)
- Jiang Liu
- Flexible Printed Electronics Technology Center and School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 China
| | - Wei Lu
- Flexible Printed Electronics Technology Center and School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 China
| | - Xifeng Lu
- Department of Physiology, Health Science Center, Shenzhen University, Shenzhen, 518055 China
| | - Lu Zhang
- Flexible Printed Electronics Technology Center and School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 China
| | - Haifeng Dong
- Marshall Laboratory of Biomedical Engineering, Research Center for Biosensor and Nanotheranostic, School of Biomedical Engineering, Shenzhen University, Shenzhen, 518055 China
| | - Yingchun Li
- Flexible Printed Electronics Technology Center and School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 China
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Mechanisms involved in antinociception induced by a polysulfated fraction from seaweed Gracilaria cornea in the temporomandibular joint of rats. Int J Biol Macromol 2017; 97:76-84. [PMID: 28065754 DOI: 10.1016/j.ijbiomac.2017.01.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 12/17/2016] [Accepted: 01/04/2017] [Indexed: 01/28/2023]
Abstract
Temporomandibular disorder is a common clinical condition involving pain in the temporomandibular joint (TMJ) region. This study assessed the antinociceptive effects of a polysulfated fraction from the red seaweed Gracilaria cornea (Gc-FI) on the formalin-induced TMJ hypernociception in rats and investigated the involvement of different mechanisms. Male Wistar rats were pretreated with injection (sc) of saline or Gc-FI 1h before intra- TMJ injection of formalin to evaluate the nociception. The results showed that pretreatment with Gc-FI significantly reduced formalin-induced nociceptive behavior. Moreover, the antinociceptive effect of the Gc-FI was blocked by naloxone (a non-selective opioid antagonist), suggesting the involvement of opioids selective receptors. Thus, the pretreatment with selective opioids receptors antagonists, reversed the antinociceptive effect of the Gc-FI in the TMJ. The Gc-FI antinociceptive effect depends on the nitric oxide/cyclic GMP/protein kinase G/ATP-sensitive potassium channel (NO/cGMP/PKG/K+ATP) pathway because it was prevented by pretreatment with inhibitors of nitric oxide synthase, guanylate cyclase enzyme, PKG and a K+ATP blocker. In addition, after inhibition with a specific heme oxygenase-1 (HO-1) inhibitor, the antinociceptive effect of the Gc-FI was not observed. Collectively, these data suggest that the antinociceptive effect induced by Gc-FI is mediated by μ/δ/κ-opioid receptors and by activation NO/cGMP/PKG/K+ATP channel pathway, besides of HO-1.
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Roth J, Blatteis CM. Mechanisms of fever production and lysis: lessons from experimental LPS fever. Compr Physiol 2015; 4:1563-604. [PMID: 25428854 DOI: 10.1002/cphy.c130033] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Fever is a cardinal symptom of infectious or inflammatory insults, but it can also arise from noninfectious causes. The fever-inducing agent that has been used most frequently in experimental studies designed to characterize the physiological, immunological and neuroendocrine processes and to identify the neuronal circuits that underlie the manifestation of the febrile response is lipopolysaccharide (LPS). Our knowledge of the mechanisms of fever production and lysis is largely based on this model. Fever is usually initiated in the periphery of the challenged host by the immediate activation of the innate immune system by LPS, specifically of the complement (C) cascade and Toll-like receptors. The first results in the immediate generation of the C component C5a and the subsequent rapid production of prostaglandin E2 (PGE2). The second, occurring after some delay, induces the further production of PGE2 by induction of its synthesizing enzymes and transcription and translation of proinflammatory cytokines. The Kupffer cells (Kc) of the liver seem to be essential for these initial processes. The subsequent transfer of the pyrogenic message from the periphery to the brain is achieved by neuronal and humoral mechanisms. These pathways subserve the genesis of early (neuronal signals) and late (humoral signals) phases of the characteristically biphasic febrile response to LPS. During the course of fever, counterinflammatory factors, "endogenous antipyretics," are elaborated peripherally and centrally to limit fever in strength and duration. The multiple interacting pro- and antipyretic signals and their mechanistic effects that underlie endotoxic fever are the subjects of this review.
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Affiliation(s)
- Joachim Roth
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University, Giessen, Germany; Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
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Branco LG, Soriano RN, Steiner AA. Gaseous Mediators in Temperature Regulation. Compr Physiol 2014; 4:1301-38. [DOI: 10.1002/cphy.c130053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Piotrowski J, Jedrzejewski T, Kozak W. Heme oxygenase-1 induction by cobalt protoporphyrin enhances fever and inhibits pyrogenic tolerance to lipopolysaccharide. J Therm Biol 2014; 45:69-74. [PMID: 25436953 DOI: 10.1016/j.jtherbio.2014.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/07/2014] [Accepted: 08/14/2014] [Indexed: 10/24/2022]
Abstract
Heme oxygenase-1 (HO-1) is an enzyme that catalyzes degradation of the heme and regulates its availability for newly synthetized hemeproteins such as cyclooxygenases, NO synthases and cytochrome P450. Moreover, HO-1 activity modulates synthesis of cytokines and prostaglandins. All of these factors are well-defined components of fever and pyrogenic tolerance mechanisms. We examine the effect of HO-1 induction and activation using cobalt protoporphyrin (CoPP) on changes in body temperature (Tb), plasma levels of interleukin-6 (IL-6), prostaglandin E₂ (PGE₂) and HO-1 protein in the course of these processes. Intraperitoneally (i.p.) pre-treatment of rats with CoPP (5 mg kg(-1)) significantly accelerated and enhanced the early stage of lipopolysaccharide (LPS)-induced fever and shortened a post-fever recovery to normal temperature. Pre-treatment with CoPP significantly potentiated the increase in plasma IL-6, PGE₂ and HO-1 levels measured 4h after the LPS administration. Furthermore, induction of HO-1 attenuated the development of pyrogenic tolerance to repeated injections of LPS. Based on these data we conclude that heme oxygenase-1 may act as a physiological regulator of the febrile response intensity to bacterial infections.
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Affiliation(s)
- Jakub Piotrowski
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4 Street, Torun 87-100, Poland; Department of Immunology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, 1 Lwowska Street, Torun 87-100, Poland.
| | - Tomasz Jedrzejewski
- Department of Immunology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, 1 Lwowska Street, Torun 87-100, Poland.
| | - Wieslaw Kozak
- Department of Immunology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, 1 Lwowska Street, Torun 87-100, Poland.
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The Janus face of the heme oxygenase/biliverdin reductase system in Alzheimer disease: it's time for reconciliation. Neurobiol Dis 2013; 62:144-59. [PMID: 24095978 DOI: 10.1016/j.nbd.2013.09.018] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 09/24/2013] [Indexed: 12/23/2022] Open
Abstract
Alzheimer disease (AD) is the most common form of dementia among the elderly and is characterized by progressive loss of memory and cognition. These clinical features are due in part to the increase of reactive oxygen and nitrogen species that mediate neurotoxic effects. The up-regulation of the heme oxygenase-1/biliverdin reductase-A (HO-1/BVR-A) system is one of the earlier events in the adaptive response to stress. HO-1/BVR-A reduces the intracellular levels of pro-oxidant heme and generates equimolar amounts of the free radical scavengers biliverdin-IX alpha (BV)/bilirubin-IX alpha (BR) as well as the pleiotropic gaseous neuromodulator carbon monoxide (CO) and ferrous iron. Two main and opposite hypotheses for a role of the HO-1/BVR-A system in AD propose that this system mediates neurotoxic and neuroprotective effects, respectively. This apparent controversy was mainly due to the fact that for over about 20years HO-1 was the only player on which all the analyses were focused, excluding the other important and essential component of the entire system, BVR. Following studies from the Butterfield laboratory that reported alterations in BVR activity along with decreased phosphorylation and increased oxidative/nitrosative post-translational modifications in the brain of subjects with AD and amnestic mild cognitive impairment (MCI) subjects, a debate was opened on the real pathophysiological and clinical significance of BVR-A. In this paper we provide a review of the main discoveries about the HO/BVR system in AD and MCI, and propose a mechanism that reconciles these two hypotheses noted above of neurotoxic and the neuroprotective aspects of this important stress responsive system.
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Hydrogen sulfide inhibits preoptic prostaglandin E2 production during endotoxemia. Exp Neurol 2013; 240:88-95. [DOI: 10.1016/j.expneurol.2012.11.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 11/01/2012] [Accepted: 11/07/2012] [Indexed: 11/18/2022]
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Brain temperature: physiology and pathophysiology after brain injury. Anesthesiol Res Pract 2012; 2012:989487. [PMID: 23326261 PMCID: PMC3541556 DOI: 10.1155/2012/989487] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 11/09/2012] [Accepted: 12/12/2012] [Indexed: 12/02/2022] Open
Abstract
The regulation of brain temperature is largely dependent on the metabolic activity of brain tissue and remains complex. In intensive care clinical practice, the continuous monitoring of core temperature in patients with brain injury is currently highly recommended. After major brain injury, brain temperature is often higher than and can vary independently of systemic temperature. It has been shown that in cases of brain injury, the brain is extremely sensitive and vulnerable to small variations in temperature. The prevention of fever has been proposed as a therapeutic tool to limit neuronal injury. However, temperature control after traumatic brain injury, subarachnoid hemorrhage, or stroke can be challenging. Furthermore, fever may also have beneficial effects, especially in cases involving infections. While therapeutic hypothermia has shown beneficial effects in animal models, its use is still debated in clinical practice. This paper aims to describe the physiology and pathophysiology of changes in brain temperature after brain injury and to study the effects of controlling brain temperature after such injury.
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Soriano R, Kwiatkoski M, Batalhao M, Branco L, Carnio E. Interaction between the carbon monoxide and nitric oxide pathways in the locus coeruleus during fever. Neuroscience 2012; 206:69-80. [DOI: 10.1016/j.neuroscience.2012.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/06/2011] [Accepted: 01/07/2012] [Indexed: 10/14/2022]
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Involvement of the heme oxygenase-carbon monoxide-cGMP pathway in the nociception induced by acute painful stimulus in rats. Brain Res 2011; 1385:107-13. [PMID: 21349250 DOI: 10.1016/j.brainres.2011.02.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 01/28/2011] [Accepted: 02/14/2011] [Indexed: 11/23/2022]
Abstract
Heme oxygenase-carbon monoxide-cGMP (HO-CO-cGMP) pathway has been reported to be involved in peripheral and spinal modulation of inflammatory pain. However, the involvement of this pathway in the modulation of acute painful stimulus in the absence of inflammation remains unknown. Thus, we evaluated the involvement of the HO-CO-cGMP pathway in nociception by means the of analgesia index (AI) in the tail flick test. Rats underwent surgery for implantation of unilateral guide cannula directed toward the lateral ventricle and after the recovery period (5-7 days) were subjected to the measures of baseline tail flick test. Animals were divided into groups to assess the effect of intracerebroventricular administration (i.c.v.) of the following compounds: ZnDPBG (HO inhibitor) or vehicle (Na(2)CO(3)), heme-lysinate (substrate overload) or vehicle (l-lysine), or the selective inhibitor of soluble guanilate cyclase ODQ or vehicle (DMSO 1%) following the administration of heme-lysinate or vehicle. Heme overload increased AI, indicating an antinociceptive role of the pathway. This response was attenuated by i.c.v. pretreatment with the HO inhibitor ZnDPBG. In addition, this effect was dependent on cGMP activity, since the pretreatment with ODQ blocked the increase in the AI. Because CO produces most of its actions via cGMP, these data strongly imply that CO is the HO product involved in the antinociceptive response. This modulation seems to be phasic rather than tonic, since i.c.v. treatment with ZnDPBG or ODQ did not alter the AI. Therefore, we provide evidence consistent with the notion that HO-CO-cGMP pathway plays a key phasic antinociceptive role modulating noninflammatory acute pain.
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Oliveira-Pelegrin GR, Branco LGS, Rocha MJA. Central NO-cGMP pathway in thermoregulation and survival rate during polymicrobial sepsis. Can J Physiol Pharmacol 2010; 88:113-20. [PMID: 20237585 DOI: 10.1139/y09-116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sepsis induces production of inflammatory mediators such as nitric oxide (NO) and causes physiological alterations, including changes in body temperature (Tb). We evaluated the involvement of the central NO-cGMP pathway in thermoregulation during sepsis induced by cecal ligation and puncture (CLP), and analyzed its effect on survival rate. Male Wistar rats with a Tb probe inserted in their abdomen were intracerebroventricularly injected with 1 microL NG-nitro-L-arginine methyl ester (L-NAME, 250 microg), a nonselective NO synthase (NOS) inhibitor; or aminoguanidine (250 microg), an inducible NOS inhibitor; or 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, 0.25 microg), a guanylate cyclase inhibitor. Thirty minutes after injection, sepsis was induced by cecal ligation and puncture (CLP), or the rats were sham operated. The animals were divided into 2 groups for determination of Tb for 24 h and assessment of survival during 3 days. The drop in Tb seen in the CLP group was attenuated by pretreatment with the NOS inhibitors (p < 0.05) and blocked with ODQ. CLP rats pretreated with either of the inhibitors showed higher survival rates than vehicle injected groups (p < 0.05), and were even higher in the ODQ pretreated group. Our results showed that the effect of NOS inhibition on the hypothermic response to CLP is consistent with the role of nitrergic pathways in thermoregulation.
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Affiliation(s)
- G R Oliveira-Pelegrin
- Biociências Aplicadas à Farmácia, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo 14040-904, Brasil
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Leong XF, Mustafa MR, Das S, Jaarin K. Association of elevated blood pressure and impaired vasorelaxation in experimental Sprague-Dawley rats fed with heated vegetable oil. Lipids Health Dis 2010; 9:66. [PMID: 20573259 PMCID: PMC2914008 DOI: 10.1186/1476-511x-9-66] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 06/23/2010] [Indexed: 12/31/2022] Open
Abstract
Background Poor control of blood pressure leads to hypertension which is a major risk factor for development of cardiovascular disease. The present study aimed to explore possible mechanisms of elevation in blood pressure following consumption of heated vegetable oil. Methods Forty-two male Sprague-Dawley rats were equally divided into six groups: Group I (control) - normal rat chow, Group II - fresh soy oil, Group III - soy oil heated once, Group IV - soy oil heated twice, Group V - soy oil heated five times, Group VI - soy oil heated ten times. Blood pressure was measured at the baseline level and at a monthly interval for six months. Plasma nitric oxide, heme oxygenase and angiotensin-converting enzyme levels were measured prior to treatment, at month-three and month-six later. At the end of treatment, the rats were sacrificed and thoracic aortas were taken for measurement of vascular reactivity. Results Blood pressure increased significantly (p < 0.01) in the repeatedly heated oil groups compared to the control and fresh soy oil groups. Consumption of diet containing repeatedly heated oil resulted higher plasma angiotensin-converting enzyme level and lower nitric oxide content and heme oxygenase concentration. Reheated soy oil groups exhibited attenuated relaxation in response to acetylcholine or sodium nitroprusside, and greater contraction to phenylephrine. Conclusion As a result of consumption of repeatedly heated soy oil, an elevation in blood pressure was observed which may be due to the quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure.
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Affiliation(s)
- Xin-Fang Leong
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
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Ghosh S, Gal J, Marczin N. Carbon monoxide: endogenous mediator, potential diagnostic and therapeutic target. Ann Med 2010; 42:1-12. [PMID: 20092397 DOI: 10.3109/07853890903482877] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The primary objectives of this article are to review the potential role of carbon monoxide (CO) as an endogenous mediator, diagnostic marker for pulmonary disorders, and therapeutic target in critical illness. The review will start by focusing on the importance of the heme oxygenase (HO)-CO axis as an endogenous system as it relates to the cardiovascular and pulmonary systems. It will elucidate the influence of HO gene expression on critical events like shock, sepsis, ischemia-reperfusion and others. Our focus will then shift and look at the potential diagnostic role of exhaled CO in major inflammatory states of the lung, and finally we will highlight the activities on inhaled CO being considered as a possible therapeutic tool and the controversies surrounding it.
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Affiliation(s)
- Subhamay Ghosh
- Department of Anaesthesiology and Intensive Therapy, University of Pecs, 7624 Pecs, Hungary.
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Helena CV, McKee DT, Bertram R, Walker AM, Freeman ME. The rhythmic secretion of mating-induced prolactin secretion is controlled by prolactin acting centrally. Endocrinology 2009; 150:3245-51. [PMID: 19282380 PMCID: PMC2703506 DOI: 10.1210/en.2009-0095] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Artificial copulomimetic cervical stimulation (CS) induces an immediate release of oxytocin (OT) and prolactin (PRL) followed by a daily PRL rhythm characterized by nocturnal and diurnal surges. Although we have shown that the initial release of PRL is induced by the immediate release of OT, we tested whether the PRL that is released in response to CS is responsible for the initiation and maintenance of the subsequent PRL surges. Thus, we injected OVX rats centrally or peripherally with ovine PRL (oPRL) at 2200 h. Central oPRL induced PRL surges in OVX rats that were similar in size and timing to those of CS rats, whereas peripheral oPRL induced surges that were of smaller amplitude and delayed. We then infused a PRL antagonist (S179D, 0.1 ng/h) centrally into OVX and OVX-CS rats and measured the release of endogenous PRL and the activity of neuroendocrine dopaminergic neurons. Central infusion of S179D did not influence basal PRL secretion in OVX rats but prevented the expression of the CS-induced PRL surges and the accompanying noontime increase of CS-induced dopaminergic activity when continued for 3 d. However, central infusion of S179D only on the day of CS did not prevent the daily rhythm of PRL surges. These results demonstrate that PRL acts centrally to induce the PRL rhythm and that PRL in the brain is essential for the maintenance but not for the initiation of the CS-induced rhythmic PRL surges.
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Affiliation(s)
- Cleyde V Helena
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4340, USA
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Wright CL, Burgoon PW, Bishop GA, Boulant JA. Cyclic GMP alters the firing rate and thermosensitivity of hypothalamic neurons. Am J Physiol Regul Integr Comp Physiol 2008; 294:R1704-15. [PMID: 18321955 DOI: 10.1152/ajpregu.00714.2007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rostral hypothalamus, especially the preoptic-anterior hypothalamus (POAH), contains temperature-sensitive and -insensitive neurons that form synaptic networks to control thermoregulatory responses. Previous studies suggest that the cyclic nucleotide cGMP is an important mediator in this neuronal network, since hypothalamic microinjections of cGMP analogs produce hypothermia in several species. In the present study, immunohistochemisty showed that rostral hypothalamic neurons contain cGMP, guanylate cyclase (necessary for cGMP synthesis), and CNG A2 (an important cyclic nucleotide-gated channel). Extracellular electrophysiological activity was recorded from different types of neurons in rat hypothalamic tissue slices. Each recorded neuron was classified according to its thermosensitivity as well as its firing rate response to 2-100 microM 8-bromo-cGMP (a membrane-permeable cGMP analog). cGMP has specific effects on different neurons in the rostral hypothalamus. In the POAH, the cGMP analog decreased the spontaneous firing rate in 45% of temperature-sensitive and -insensitive neurons, an effect that is likely due to cGMP-enhanced hyperpolarizing K(+) currents. This decreased POAH activity could attenuate thermoregulatory responses and produce hypothermia during exposures to cool or neutral ambient temperatures. Although 8-bromo-cGMP did not affect the thermosensitivity of most POAH neurons, it did increase the warm sensitivity of neurons in other hypothalamic regions located dorsal, lateral, and posterior to the POAH. This increased thermosensitivity may be due to pacemaker currents that are facilitated by cyclic nucleotides. If some of these non-POAH thermosensitive neurons promote heat loss or inhibit heat production, then their increased thermosensitivity could contribute to cGMP-induced decreases in body temperature.
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Affiliation(s)
- Chadwick L Wright
- Department of Physiology & Cell Biology, Ohio State University, Columbus, OH 43210, USA
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20
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Geeraerts T, Leblanc PE, Dufour G, Tazarourte K, Duranteau J, Vigué B. [Intracerebral monitoring of a patient with vasopasm]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2007; 26:973-979. [PMID: 17936565 DOI: 10.1016/j.annfar.2007.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Delayed neurological deficit occurs among 30% of patients after aneurysmal subarachnoid haemorrhage, mainly related to cerebral vasospasm. The early detection of cerebral ischemia remains problematic. Conventional cerebral monitoring (as intracranial pressure and cerebral perfusion pressure) appears to be insufficient, because cerebral ischemia may occur without elevated intracranial pressure. Global cerebral monitoring as venous jugular oxygen saturation are useful for regional monitoring. Local monitoring as oxygen tissue partial pressure (PtiO2) and microdialysis are sensible for brain ischemia detection, but may also ignore episodes occurring in non-monitored brain area. For the detection of most episodes of brain ischemia, several monitoring system should be use performing a multimodal intracerebral monitoring. Brain microdialysis and oxygen tissue partial pressure are promising monitoring system.
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Affiliation(s)
- T Geeraerts
- Service du Professeur-Benhamou, département d'anesthésie-réanimation chirurgicale, hôpital de Bicêtre, Assistance publique-Hôpitaux de Paris, et faculté de médecine Paris-Sud, Le Kremlin-Bicêtre, France.
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21
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Role of locus coeruleus heme oxygenase-carbon monoxide-cGMP pathway during hypothermic response to restraint. Brain Res Bull 2007; 75:526-32. [PMID: 18355628 DOI: 10.1016/j.brainresbull.2007.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 08/16/2007] [Accepted: 09/07/2007] [Indexed: 02/02/2023]
Abstract
Central heme oxigenase-carbon monoxide (HO-CO) pathway has been shown to play a pyretic role in the thermoregulatory response to restraint. However, the specific site in the central nervous system where CO may act modulating this response remains unclear. LC is rich not only in sGC but also in heme oxygenase (HO; the enzyme that catalyses the metabolism of heme to CO, along with biliverdin and free iron). Therefore, the possible role of the HO-CO-cGMP pathway in the restraint-induced-hypothermia by LC neurons was investigated. Body temperature dropped about 0.7 degrees C during restraint. ZnDPBG (a HO inhibitor; 5 nmol, intra-LC) prevented the hypothermic response during restraint. Conversely, induction of the HO pathway in the LC with heme-lysinate (7.6 nmol, intra-LC) intensified the hypothermic response to restraint, and this effect was prevented by pretreatment with ODQ (a sGC inhibitor; given intracerebroventricularly, 1.3 nmol). Taken together, these data suggest that CO in the LC produced by the HO pathway and acting via cGMP is implicated in thermal responses to restraint.
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22
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Ravanelli MIB, Almeida MC, Branco LGS. Role of the locus coeruleus carbon monoxide pathway in endotoxin fever in rats. Pflugers Arch 2006; 453:471-6. [PMID: 16941138 DOI: 10.1007/s00424-006-0136-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 07/04/2006] [Indexed: 11/25/2022]
Abstract
Carbon monoxide (CO) has been identified as a diffusible signaling messenger in the brain, capable of altering body temperature by stimulating soluble guanylate cyclase (sGC). However, its site of action remains unclear. Locus coeruleus (LC) is rich not only in sGC but also in heme oxygenase (HO; the enzyme that catalyses the metabolism of heme to CO, along with biliverdin and free iron). Therefore, the possible role of the HO-CO-cGMP pathway in the lipopolysaccharide (LPS)-induced fever regulation by LC neurones was investigated. Induction of the HO pathway using heme-lysinate (7.6 nmol, intra-LC) attenuated the febrile response, and this effect could be prevented by pretreatment with ODQ (an sGC inhibitor; given intracerebroventricularly, 1.3 nmol). Moreover, ZnDPBG (an HO inhibitor; 5 nmol, intra-LC) augmented the febrile response. Taken together, these data suggest that CO in the LC produced by the HO pathway and acting via cGMP plays an antipyretic role during LPS-fever in rats.
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Affiliation(s)
- Maria Ida Bonini Ravanelli
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, SP, Brazil
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23
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Baig MS, Joseph V. Activation of NMDA receptors prevents excessive metabolic decrease in hypoxic rat pups. Respir Physiol Neurobiol 2006; 152:61-71. [PMID: 16040283 DOI: 10.1016/j.resp.2005.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 06/17/2005] [Accepted: 06/18/2005] [Indexed: 11/29/2022]
Abstract
We tested the hypothesis that glutamate NMDA receptors may help maintain metabolic rate and body temperature during acute or chronic hypoxic exposure in newborn rats. We recorded ventilation, metabolism ((.)V(O(2)) -- ((.)V(CO(2)) and rectal temperature, under normoxia, acute hypoxia (30 min -- 12% O(2)), or following 10 days of chronic hypoxia, in 10 days old male and female rats, receiving saline i.p. injection or the NMDA receptor antagonist MK-801. Acute hypoxia decreased rectal temperature and metabolism, and increased ventilation, and (.)V(E)/((.)V(O(2) and (.)V(E)/((.)V(CO(2) to the same extent in males and females. MK-801 injection amplified the metabolic decrease under acute (in males and females) and chronic (in males) hypoxia, prevented the increase of minute ventilation, while (.)V(E)/((.)V(O(2) or (.)V(E)/((.)V(CO(2)remained constant. Hence, NMDA glutamate receptors help to maintain metabolic rate, minute ventilation and body temperature at a determined level in acute (males and females) and chronic hypoxia (males only).
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Affiliation(s)
- Mirza Shafiulla Baig
- Department of Pediatrics, Laval University, Centre de Recherche (D0-711), Hôpital St-François d'Assise, 10 rue de l'Espinay, Que. (QC), Canada G1L 3L5
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24
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Ewing JF, Maines MD. Regulation and expression of heme oxygenase enzymes in aged-rat brain: age related depression in HO-1 and HO-2 expression and altered stress-response. J Neural Transm (Vienna) 2006; 113:439-54. [PMID: 16467964 DOI: 10.1007/s00702-005-0408-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Accepted: 09/26/2005] [Indexed: 10/25/2022]
Abstract
The heme oxygenase isozymes, HO-1 and HO-2, oxidatively cleave the heme molecule to produce biliverdin and the gaseous messenger, CO. The cleavage results in the release of iron, a regulator of transferrin, ferritin, and nitric oxide (NO) synthase gene expression. Biliverdin reductase (BVR) then catalyzes the reduction of biliverdin, generating the potent intracellular antioxidant, bilirubin. We report an age-related decrease in HO-1 and HO-2 expression present in select brain regions including the hippocampus and the substantia nigra, that are involved in the high order cognitive processes of learning and memory. The age-related loss of monoxide-producing potential in select regions of the brain was not specific to the HO system but was also observed in neuronal NO-generating system. Furthermore, compared to 2-month old rats, the ability of aged brain tissue to respond to hypoxic/hyperthermia was compromised at both the protein and the transcription levels as judged by attenuated induction of HO-1 immunoreactive protein and its 1.8 Kb transcript. Neotrofin (AIT), a cognitive-enhancing and neuroprotective drug, caused a robust increase in HO-1 immunoreactive protein in select neuronal regions and increased the expression of HO-2 transcripts. The potential interplay between regulation of HO-2 gene expression and the serum levels of the adrenal steroids is discussed. We suggest the search for therapeutic agents that reverse the decline and aberrant stress response of HO enzymes may lead to effective treatment regimens for age-associated neuronal deficits.
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Affiliation(s)
- J F Ewing
- Department of Biochemistry/Biophysics, University of Rochester School of Medicine, Rochester, NY 14642, USA
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25
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Shi F, Stewart RL, Perez E, Chen JYH, LaPolt PS. Cell-specific expression and regulation of soluble guanylyl cyclase alpha 1 and beta 1 subunits in the rat ovary. Biol Reprod 2004; 70:1552-61. [PMID: 14749300 DOI: 10.1095/biolreprod.103.025510] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Soluble guanylyl cyclase (sGC) is activated by nitric oxide (NO) and carbon monoxide, resulting in cGMP production. Recent studies indicate that NO and cGMP influence ovarian functions. However, little information is available regarding the ovarian expression of sGC. The present study examined sGC alpha(1) and beta(1) subunit protein levels in the ovary during postnatal development, gonadotropin-induced follicle growth, ovulation, and luteinization as well as in cultured rat granulosa cells. In postnatal rats, sGC alpha(1) subunit immunoreactivity was high in granulosa cells of primordial and primary follicles on Day 5 but low in granulosa cells of larger follicles on Days 10 and 19. Theca cells of developing follicles, but not stromal cells, also demonstrated moderate sGC alpha(1) immunoreactivity. In gonadotropin- treated immature rats, intense sGC alpha(1) subunit staining was similarly observed in granulosa cells of primordial and primary follicles, but such staining was low in granulosa cells of small antral follicles and undetectable in granulosa cells of large antral and preovulatory follicles. Following ovulation, corpora lutea expressed moderate sGC alpha(1) immunoreactivity. Similar ovarian localization and expression patterns were seen for sGC beta(1), indicating regulated coexpression of sGC subunits. Immunoblot analysis revealed no change in total ovarian sGC alpha(1) and beta(1) subunit protein levels during gonadotropin treatment. Similarly, no effect of FSH on sGC subunit protein levels was apparent in cultured granulosa cells. These findings indicate regulated, cell- specific patterns of sGC expression in the ovary and are consistent with roles for cGMP in modulating ovarian functions.
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Affiliation(s)
- Fangxiong Shi
- Department of Biological Sciences, California State University-Los Angeles, Los Angeles, California 90032, USA
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Naik JS, Walker BR. Heme oxygenase-mediated vasodilation involves vascular smooth muscle cell hyperpolarization. Am J Physiol Heart Circ Physiol 2003; 285:H220-8. [PMID: 12637349 DOI: 10.1152/ajpheart.01131.2002] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Chronic hypoxia is associated with both blunted agonist-induced and myogenic vascular reactivity and is possibly due to an enhanced production of heme oxygenase (HO)-derived carbon monoxide (CO). However, the mechanism of endogenous CO-meditated vasodilation remains unclear. Isolated pressurized mesenteric arterioles from chronically hypoxic rats were administered the HO substrate heme-l-lysinate (HLL) in the presence or absence of iberiotoxin, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), ryanodine, or free radical spin traps (N-tert-butyl-alpha-phenylnitrone and 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt). The effects of HLL administration on vascular smooth muscle (VSM) membrane potential were assessed in superior mesenteric artery strips in the presence and absence of zinc protoporphyrin IX or iberiotoxin. The vasodilatory responses to exogenous CO were assessed in the presence and absence of ODQ or iberiotoxin. HLL administration produced a dose-dependent vasodilatory response that was nearly eliminated in the presence of iberiotoxin. Neither ODQ, spin traps, nor ryanodine altered the vasodilatory response to HLL, although ODQ abolished the vasodilatory response to S-nitroso-N-acetyl-penicillamine. HLL administration produced a zinc protoporphyrin IX- and iberiotoxin-sensitive VSM cell hyperpolarization. Iberiotoxin and ODQ inhibited the vasodilatory response to exogenous CO. Thus the vasodilatory response to endogenous CO involves cGMP-independent activation of VSM large-conductance Ca2+-activated K+ channels and does not likely involve the formation of Ca2+ sparks emanating from ryanodine-sensitive stores.
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Affiliation(s)
- Jay S Naik
- Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-5218, USA
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27
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Affiliation(s)
- Holger Scholz
- Johannes-Müller-Institut für Physiologie, Medizinische Fakultät Charité, Humboldt-Universität Berlin, 10117 Berlin, Germany.
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28
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Affiliation(s)
- Gerald F DiBona
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
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29
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Jang CG, Lee SJ, Yang SI, Kim JH, Sohn UD, Lee SY. Carbon monoxide as a novel central pyrogenic mediator. Arch Pharm Res 2002; 25:343-8. [PMID: 12135108 DOI: 10.1007/bf02976637] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Carbon monoxide (CO) are produced by heme oxygenase (HO), and HO was detected in hypothalamus. However, the roles of CO produced in hypothalamus was not fully elucidated. So, we tested the effects of CO on body temperature because preoptic-anterior hypothalamus was known as the presumptive primary fever-producing site. CO-saturated aCSF (4 microl, i.c.v.) and hemin (10 microg, i.c.v.) elicited marked febrile response. Pretreatment with indomethacin completely inhibited CO- and hemin-induced fever. Zinc protoporphyrin-IX (10 microg, i.c.v.) or ODQ (50 microg, i.c.v.) partially reduced hemin-induced febrile response. Dibutyryl-cGMP (100 microg, i.c.v.) produced profound febrile response and this febrile response was attenuated by indomethacin. These results indicate that endogenous CO may have a role as a pyrogenic mediator in CNS and CO-mediated pyresis is dependent on prostaglandin production and partially on activation of soluble guanylate cyclase.
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Affiliation(s)
- Choon-Gon Jang
- Lab of Pharmacology, College of Pharmacy, Sungkyunkwan University, Suwon, Korea
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Abstract
Hypoxia elicits an array of compensatory responses in animals ranging from protozoa to mammals. Central among these responses is anapyrexia, the regulated decrease of body temperature. The importance of anapyrexia lies in the fact that it reduces oxygen consumption, increases the affinity of hemoglobin for oxygen, and blunts the energetically costly responses to hypoxia. The mechanisms of anapyrexia are of intense interest to physiologists. Several substances, among them lactate, adenosine, opioids, and nitric oxide, have been suggested as putative mediators of anapyrexia, and most appear to act in the central nervous system. Moreover, there is evidence that the drop in body temperature in response to hypoxia, unlike the ventilatory response to hypoxia, does not depend on the activation of peripheral chemoreceptors. The current knowledge of the mechanisms of hypoxia-induced anapyrexia are reviewed.
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Affiliation(s)
- Alexandre A Steiner
- Department of Morphology, Estomatology and Physiology, Dental School of Ribeirão Preto, SP, Brazil.
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Abstract
In this paper, selected historical aspects of thermoregulation and fever are presented as background to the application of molecular biology to thermoregulation. Temperature-sensing mechanisms, coordination of thermal information, thermoregulatory circuitry, efferent responses to thermal stimuli, set point mechanisms, and some of the mechanisms and consequences of fever and hyperthermia are highlighted. Neurotransmitters used in thermoregulatory circuits are also discussed. An attempt is made to include information from comparative physiological sources. Possible future avenues of research in the light of recent new technologies are also presented.
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Affiliation(s)
- K E Cooper
- Department of Physiology and Biophysics, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1.
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Lee HU, Lee HJ, Park HY, Lee SH, Jang CG, Lee SY. Effects of heme oxygenase system on the cyclooxygenase in the primary cultured hypothalamic cells. Arch Pharm Res 2001; 24:607-12. [PMID: 11794544 DOI: 10.1007/bf02975174] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Endogenous carbon monoxide (CO) shares with nitric oxide (NO) a role as a putative neural messenger in the brain. Both gases are believed to modulate CNS function via an increase in cytoplasmic cGMP concentrations secondary to the activation of soluble guanylate cyclase (sGC). Recently CO and NO were proposed as a possible mediator of febrile response in hypothalamus. NO has been reported to activate both the constitutive and inducible isoform of the cyclooxygenase (COX). Thus, we investigated whether CO arising from heme catabolism by heme oxygenase (HO) is involved in the febrile response via the activation of COX in the hypothalamus. PGE2 which is a final mediator of febrile response released from primary cultured hypothalamic cells was taken as a marker of COX activity. PGE2 concentration was measured with EIA kits. Exogenous CO (CO-saturated medium) and hemin (a substrate and potent inducer of HO) evoked an increase in PGE2 release from hypothalamic cells, and these effects were blocked by methylene blue (an inhibitor of sGC). And membrane permeable cGMP analogue, dibutyryl-cGMP elicited significant increases in PGE2 release. These results suggest that there may be a functional link between HO and COX enzymatic activities. The gaseous product of hemin through the HO pathway, CO, might play a role through the modulation of the COX activity in the hypothalamus.
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Affiliation(s)
- H U Lee
- Lab of Pharmacology, College of Pharmacy, Sungkyunkwan University, Suwon, Korea
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33
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Naik JS, Walker BR. Homogeneous segmental profile of carbon monoxide-mediated pulmonary vasodilation in rats. Am J Physiol Lung Cell Mol Physiol 2001; 281:L1436-43. [PMID: 11704540 DOI: 10.1152/ajplung.2001.281.6.l1436] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Carbon monoxide (CO) has been proposed to attenuate the vasoconstrictor response to local hypoxia that contributes to pulmonary hypertension. However, the segmental response to CO, as well as its mechanism of action in the pulmonary circulation, has not been fully defined. To investigate the hemodynamic response to exogenous CO, lungs from male Sprague-Dawley rats were perfused with physiological saline solution. Measurements were made of pulmonary arterial, venous, and capillary pressures. Lungs were constricted with the thromboxane mimetic U-46619. To examine the vasodilatory response to CO, 500 microl of CO-equilibrated physiological saline solution or vehicle were injected into the arterial line. Additionally, CO and vehicle responses were examined in the presence of the soluble guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 microM) or the larger conductance calcium-activated K(+) (BK(Ca)) channel blockers tetraethylammonium chloride (10 mM) and iberiotoxin (100 nM). CO administration decreased vascular resistance to a similar degree in both vascular segments. This vasodilatory response was completely abolished in lungs pretreated with ODQ. Furthermore, CO administration increased whole lung cGMP content, which was prevented by ODQ. Neither tetraethylammonium chloride nor iberiotoxin affected the CO response. We conclude that exogenous CO administration causes vasodilation in the pulmonary vasculature via a soluble guanylyl cyclase-dependent mechanism that does not likely involve activation of K(Ca) channels.
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Affiliation(s)
- J S Naik
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131-5218, USA
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