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Passaglia P, Silva HB, de Jesus AA, Filho MAM, Trajano IP, Batalhão ME, Navegantes LCC, Branco LGS, Cárnio EC. Angiotensin-(1-7) improves tail skin heat loss and increases the survival of rats with polymicrobial sepsis. Peptides 2023; 167:171042. [PMID: 37315714 DOI: 10.1016/j.peptides.2023.171042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/02/2023] [Accepted: 06/08/2023] [Indexed: 06/16/2023]
Abstract
Sepsis is a serious syndrome, characterized by the excessive release of inflammatory mediators and thermoregulatory changes, being fever the most common sign. However, despite the importance of Angiotensin (Ang)-(1-7) in controlling the inflammation, the role of the peptide in the febrile response and mortality in animals submitted to experimental model of sepsis is still not clear. In this way, we evaluate the effect of continuous infusion of Ang-(1-7) in inflammatory response, thermoregulation and in mortality of Wistar male rats submitted to colonic ligation puncture (CLP). Before CLP surgery, the infusion pumps (Ang-(1-7), 1.5mg/mL or saline) were inserted into the abdominal cavity and maintained for 24hours. CLP rats showed a febrile response starting from 3h after and persisted until the 24th hour of experiment. Continuous treatment with Ang-(1-7) attenuated the febrile response and reestablished the euthermia 11h after CLP, until the end of experiment, which coincided with an increased heat loss index (HLI). This effect was associated with a decrease in production of pro-inflammatory mediators in liver, white adipose tissue (WAT) and hypothalamus. Moreover, an increase in norepinephrine (NE) content in interscapular brown adipose tissue (iBAT) was observed in CLP animals, which was attenuated with treatment with Ang-(1-7), and decreased mortality in CLP animals treated with Ang-(1-7). Taken together, the present study demonstrates that continuous infusion treatment with Ang-(1-7) can promote a global anti-inflammatory effect, reestablishing the tail skin heat loss as a key thermo-effector function, resulting in an increased survival of animals submitted to experimental sepsis.
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Affiliation(s)
- Patrícia Passaglia
- Department of Oral and Basic Biology Ribeirão Preto, School of Dentistry of Ribeirão Preto - University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Hadder Batista Silva
- Department of General Nursing, School of Nursing of Ribeirão Preto - University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Aline Alves de Jesus
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Marco Antonio Marangão Filho
- Department of General Nursing, School of Nursing of Ribeirão Preto - University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Isis Paiva Trajano
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Marcelo Eduardo Batalhão
- Department of General Nursing, School of Nursing of Ribeirão Preto - University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Luiz Guilherme Siqueira Branco
- Department of Oral and Basic Biology Ribeirão Preto, School of Dentistry of Ribeirão Preto - University of São Paulo, Ribeirão Preto, SP, Brazil; Department of Physiology, Ribeirão Preto Medical School - University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Evelin Capellari Cárnio
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo, Ribeirão Preto, SP, Brazil; Department of General Nursing, School of Nursing of Ribeirão Preto - University of São Paulo, Ribeirão Preto, SP, Brazil
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Ayoub SS. Paracetamol (acetaminophen): A familiar drug with an unexplained mechanism of action. Temperature (Austin) 2021; 8:351-371. [PMID: 34901318 PMCID: PMC8654482 DOI: 10.1080/23328940.2021.1886392] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/26/2021] [Accepted: 02/01/2021] [Indexed: 02/02/2023] Open
Abstract
Paracetamol (acetaminophen) is undoubtedly one of the most widely used drugs worldwide. As an over-the-counter medication, paracetamol is the standard and first-line treatment for fever and acute pain and is believed to remain so for many years to come. Despite being in clinical use for over a century, the precise mechanism of action of this familiar drug remains a mystery. The oldest and most prevailing theory on the mechanism of analgesic and antipyretic actions of paracetamol relates to the inhibition of CNS cyclooxygenase (COX) enzyme activities, with conflicting views on the COX isoenzyme/variant targeted by paracetamol and on the nature of the molecular interactions with these enzymes. Paracetamol has been proposed to selectively inhibit COX-2 by working as a reducing agent, despite the fact that in vitro screens demonstrate low potency on the inhibition of COX-1 and COX-2. In vivo data from COX-1 transgenic mice suggest that paracetamol works through inhibition of a COX-1 variant enzyme to mediate its analgesic and particularly thermoregulatory actions (antipyresis and hypothermia). A separate line of research provides evidence on potentiation of the descending inhibitory serotonergic pathway to mediate the analgesic action of paracetamol, but with no evidence of binding to serotonergic molecules. AM404 as a metabolite for paracetamol has been proposed to activate the endocannabinoid and the transient receptor potential vanilloid-1 (TRPV1) systems. The current review gives an update and in some cases challenges the different theories on the pharmacology of paracetamol and raises questions on some of the inadequately explored actions of paracetamol. List of Abbreviations: AM404, N-(4-hydroxyphenyl)-arachidonamide; CB1R, Cannabinoid receptor-1; Cmax, Maximum concentration; CNS, Central nervous system; COX, Cyclooxygenase; CSF, Cerebrospinal fluid; ED50, 50% of maximal effective dose; FAAH, Fatty acid amidohydrolase; IC50, 50% of the maximal inhibitor concentration; LPS, Lipopolysaccharide; NSAIDs, Non-steroidal anti-inflammatory drugs; PGE2, Prostaglandin E2; TRPV1, Transient receptor potential vanilloid-1.
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Affiliation(s)
- Samir S Ayoub
- School of Health, Sport and Bioscience, Medicines Research Group, University of East London, London, UK
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3
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Loss of hypothermic and anti-pyretic action of paracetamol in cyclooxygenase-1 knockout mice is indicative of inhibition of cyclooxygenase-1 variant enzymes. Eur J Pharmacol 2019; 861:172609. [DOI: 10.1016/j.ejphar.2019.172609] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 08/09/2019] [Accepted: 08/14/2019] [Indexed: 02/02/2023]
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Central fractalkine stimulates central prostaglandin E 2 production and induces systemic inflammatory responses. Brain Res Bull 2018; 140:311-317. [PMID: 29870777 DOI: 10.1016/j.brainresbull.2018.05.024] [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: 11/14/2017] [Revised: 04/23/2018] [Accepted: 05/31/2018] [Indexed: 11/20/2022]
Abstract
Fractalkine (FKN; CX3CL1) belongs to gamma-chemokine family and binds to CX3CR1 receptors. Currently, the mechanisms involving FKN-induced inflammatory mediators are research targets in an attempt to study immune diseases mechanisms. Besides, FKN seems to modulate inflammation in the nervous system by inducing the secretion of pro-inflammatory mediators such as prostaglandin E2 (PGE2). PGE2 is a classic and important mediator of fever that activates warm-responsive neurons in the anteroventral preoptic region of the hypothalamus (AVPO). Here, we tested the hypothesis that central FKN modulates febrigenic signaling both centrally and peripherally. We performed intracerebroventricular (icv) microinjections of saline (1 μL) or FKN (doses of 5, 50, 500 pg/μL) in rats and measured body temperature (Tb) besides assessing tail skin temperature (Tsk) as a thermoeffector indicator used to calculate the heat loss index (HLI). We also measured the time course changes in AVPO PGE2, besides plasma corticosterone (CORT) and interleukin-6 (IL-6) levels. FKN induced a long lasting febrile response in which the highest dose (500 pg/μL) induced a marked rise on Tb that was accompanied by a reduced Tsk and HLI, consequently. FKN increased AVPO PGE2 production in a time-dependent manner besides increasing plasma CORT and IL-6 levels. Our data consistently indicate that FKN increases AVPO PGE2 production and Tb, accompanied by raised plasma IL-6 levels and activation of the hypothalamus-pituitary-adrenal axis.
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Prostaglandin Transporter OATP2A1/ SLCO2A1 Is Essential for Body Temperature Regulation during Fever. J Neurosci 2018; 38:5584-5595. [PMID: 29899035 DOI: 10.1523/jneurosci.3276-17.2018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 05/07/2018] [Accepted: 05/11/2018] [Indexed: 01/24/2023] Open
Abstract
Prostaglandin E2 (PGE2) in the hypothalamus is a principal mediator of the febrile response. However, the role of organic anion transporting polypeptide 2A1 (OATP2A1/SLCO2A1), a prostaglandin transporter, in facilitating this response is unknown. Here, we investigated the effect of Slco2a1 deficiency on the body core temperature (Tc) and on the PGE2 concentration in hypothalamus interstitial fluid (Cisf) and CSF (Ccsf) of lipopolysaccharide (LPS; 100 μg/kg, i.p.)-treated mice of both sexes. Slco2a1-/- mice did not develop a febrile response. Ccsf was increased in Slco2a1+/+ and Slco2a1-/- mice, and Ccsf of Slco2a1-/- mice was well maintained at 5 h after LPS injection (1160 pg/ml) compared with Slco2a1+/+ mice (316 pg/ml). A microdialysis study revealed that Cisf peaked at 2 h after LPS injection in Slco2a1+/+ mice (841 pg/ml), whereas the increase in Cisf was negligible in Slco2a1-/- mice. The PGE2 plasma concentration in Slco2a1-/- mice (201 pg/ml) was significantly higher than that in Slco2a1+/+ mice (54 pg/ml) at 1 h after LPS injection, whereas the two groups showed similar PGE2 concentrations in the hypothalamus. Strong Oatp2a1 immunoreactivity was observed in F4/80-positive microglia and perivascular cells and in brain capillary endothelial cells. The changes in Tc and Cisf seen in LPS-injected Slco2a1+/+ mice were partially attenuated in monocyte-/macrophage-specific Slco2a1-/- (Slco2a1Fl/Fl/LysMCre/+) mice. Thus, OATP2A1 facilitates the LPS-induced febrile response by maintaining a high level of Cisf, possibly by regulating PGE2 secretion from F4/80-positive glial cells and/or facilitating PGE2 transport across the blood-brain barrier. These findings suggest that OATP2A1 is a useful therapeutic target for neuroinflammation.SIGNIFICANCE STATEMENT Fever is a physiological response caused by pyrogen-induced release of prostaglandin E2 (PGE2) in the hypothalamus, which plays a central role in regulating the set-point of body temperature. However, it is unclear whether the prostaglandin transporter OATP2A1/SLCO2A1 is involved in this response. We show here that LPS-induced fever is associated with increased PGE2 concentration in hypothalamus interstitial fluid (Cisf), but not in CSF (Ccsf), by means of a microdialysis study in global Slco2a1-knock-out mice and monocyte-/macrophage-specific Slco2a1-knock-out mice. The results suggest that OATP2A1 serves as a regulator of Cisf in F4/80-positive glial cells. OATP2A1 was detected immunohistochemically in brain capillary endothelial cells and, therefore, may also play a role in PGE2 transport across the blood-brain barrier.
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Pakai E, Tekus V, Zsiboras C, Rumbus Z, Olah E, Keringer P, Khidhir N, Matics R, Deres L, Ordog K, Szentes N, Pohoczky K, Kemeny A, Hegyi P, Pinter E, Garami A. The Neurokinin-1 Receptor Contributes to the Early Phase of Lipopolysaccharide-Induced Fever via Stimulation of Peripheral Cyclooxygenase-2 Protein Expression in Mice. Front Immunol 2018; 9:166. [PMID: 29459872 PMCID: PMC5807668 DOI: 10.3389/fimmu.2018.00166] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/18/2018] [Indexed: 12/20/2022] Open
Abstract
Neurokinin (NK) signaling is involved in various inflammatory processes. A common manifestation of systemic inflammation is fever, which is usually induced in animal models with the administration of bacterial lipopolysaccharide (LPS). A role for the NK1 receptor was shown in LPS-induced fever, but the underlying mechanisms of how the NK1 receptor contributes to febrile response, especially in the early phase, have remained unknown. We administered LPS (120 µg/kg, intraperitoneally) to mice with the Tacr1 gene, i.e., the gene encoding the NK1 receptor, either present (Tacr1+/+ ) or absent (Tacr1-/- ) and measured their thermoregulatory responses, serum cytokine levels, tissue cyclooxygenase-2 (COX-2) expression, and prostaglandin (PG) E2 concentration. We found that the LPS-induced febrile response was attenuated in Tacr1-/- compared to their Tacr1+/+ littermates starting from 40 min postinfusion. The febrigenic effect of intracerebroventricularly administered PGE2 was not suppressed in the Tacr1-/- mice. Serum concentration of pyrogenic cytokines did not differ between Tacr1-/- and Tacr1+/+ at 40 min post-LPS infusion. Administration of LPS resulted in amplification of COX-2 mRNA expression in the lungs, liver, and brain of the mice, which was statistically indistinguishable between the genotypes. In contrast, the LPS-induced augmentation of COX-2 protein expression was attenuated in the lungs and tended to be suppressed in the liver of Tacr1-/- mice compared with Tacr1+/+ mice. The Tacr1+/+ mice responded to LPS with a significant surge of PGE2 production in the lungs, whereas Tacr1-/- mice did not. In conclusion, the NK1 receptor is necessary for normal fever genesis. Our results suggest that the NK1 receptor contributes to the early phase of LPS-induced fever by enhancing COX-2 protein expression in the periphery. These findings advance the understanding of the crosstalk between NK signaling and the "cytokine-COX-2-prostaglandin E2" axis in systemic inflammation, thereby open up the possibilities for new therapeutic approaches.
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Affiliation(s)
- Eszter Pakai
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary.,Momentum Gastroenterology Multidisciplinary Research Group, Hungarian Academy of Sciences - University of Szeged, Szeged, Hungary
| | - Valeria Tekus
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pecs, Pecs, Hungary.,Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Csaba Zsiboras
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Zoltan Rumbus
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Emoke Olah
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Patrik Keringer
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Nora Khidhir
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Robert Matics
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Laszlo Deres
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary.,First Department of Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Katalin Ordog
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary.,First Department of Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Nikolett Szentes
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pecs, Pecs, Hungary.,Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Krisztina Pohoczky
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pecs, Pecs, Hungary.,Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Agnes Kemeny
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary.,Department of Medical Biology, Medical School, University of Pecs, Pecs, Hungary
| | - Peter Hegyi
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary.,Momentum Gastroenterology Multidisciplinary Research Group, Hungarian Academy of Sciences - University of Szeged, Szeged, Hungary.,First Department of Medicine, University of Szeged, Szeged, Hungary
| | - Erika Pinter
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pecs, Pecs, Hungary.,Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Andras Garami
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
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7
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Garami A, Steiner AA, Romanovsky AA. Fever and hypothermia in systemic inflammation. HANDBOOK OF CLINICAL NEUROLOGY 2018; 157:565-597. [PMID: 30459026 DOI: 10.1016/b978-0-444-64074-1.00034-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Systemic inflammation-associated syndromes (e.g., sepsis and septic shock) often have high mortality and remain a challenge in emergency medicine. Systemic inflammation is usually accompanied by changes in body temperature: fever or hypothermia. In animal studies, systemic inflammation is often modeled by administering bacterial lipopolysaccharide, which triggers autonomic and behavioral thermoeffector responses and causes either fever or hypothermia, depending on the dose and ambient temperature. Fever and hypothermia are regulated changes of body temperature, which correspond to mild and severe forms of systemic inflammation, respectively. Mediators of fever and hypothermia are called endogenous pyrogens and cryogens; they are produced when the innate immune system recognizes an infectious pathogen. Upon an inflammatory challenge, hepatic and pulmonary macrophages (and later brain endothelial cells) start to release lipid mediators, of which prostaglandin (PG) E2 plays the key role, and cytokines. Blood PGE2 enters the brain and triggers fever. At later stages of fever, PGE2 synthesized within the blood-brain barrier maintains fever. In both cases, PGE2 is synthesized by cyclooxygenase-2 and microsomal PGE2synthase-1. Mediators of hypothermia are not well established. Both fever and hypothermia are beneficial host defense responses. Based on evidence from studies in laboratory animals and clinical trials in humans, fever is beneficial for fighting mild infection. Based mainly on animal studies, hypothermia is beneficial in severe systemic inflammation and infection.
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Affiliation(s)
- Andras Garami
- Institute for Translational Medicine, Medical School, University of Pécs, Pécs, Hungary.
| | - Alexandre A Steiner
- Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Andrej A Romanovsky
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States
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Abstract
Fever depends on a complex physiologic response to infectious agents and other conditions. To alleviate fever, many medicinal agents have been developed over a century of trying to improve upon aspirin, which was determined to work by inhibiting prostaglandin synthesis. We present the process of fever induction through prostaglandin synthesis and discuss the development of pharmaceuticals that target enzymes and receptors involved in prostaglandin-mediated signal transduction, including prostaglandin H2 synthase (also known as cyclooxygenase), phospholipase A2, microsomal prostaglandin E2 synthase-1, EP receptors, and transient potential cation channel subfamily V member 1. Clinical use of established antipyretics will be discussed as well as medicinal agents under clinical trials and future research.
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Affiliation(s)
- Jonathan J Lee
- Biochemistry Department, Brigham Young University, Provo, UT, United States
| | - Daniel L Simmons
- Biochemistry Department, Brigham Young University, Provo, UT, United States.
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9
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Mota CMD, Rodrigues-Santos C, Fernández RAR, Carolino ROG, Antunes-Rodrigues J, Anselmo-Franci JA, Branco LGS. Central serotonin attenuates LPS-induced systemic inflammation. Brain Behav Immun 2017; 66:372-381. [PMID: 28723348 DOI: 10.1016/j.bbi.2017.07.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/06/2017] [Accepted: 07/15/2017] [Indexed: 12/21/2022] Open
Abstract
Serotonin (5-HT) is a neuromodulator involved in several central-mediated mechanisms, such as endocrine processes, behavior, and sleep. Dysfunction of the serotonergic system is mainly linked to psychiatric disorders, but emerging evidence suggests that immune system activation may also alter brain 5-HT signaling. However, whether central 5-HT modulates systemic inflammation (SI) remains unknown. For this purpose, male Wistar rats (280-350g, 8-9weeks) were submitted to the experimental protocols beginning between 9 and 10AM with the performance of injections. The animals were housed at controlled conditions [temperature (25±1°C), light (06:00-18:00) and humidity (60-65%)]. Thus, we measured 5-HT and its metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) in the anteroventral preoptic region [(AVPO) - the hierarchically most important region for body temperature (Tb) control] during lipopolysaccharide (LPS)-induced SI. We also combined LPS (100μg/kg) treatment with intracerebroventricular (icv) injection of 5-HT (5, 10 and 40μg/μL) and measured Tb ("hallmark" of SI), AVPO prostaglandin E2 [(PGE2) - an essential mediator of fever] and prostaglandin D2 [(PGD2) - a cryogenic mediator], plasma corticosterone [(CORT) - a stress marker with an endogenous anti-inflammatory effect] and interleukin-6 [(IL-6) - an immune mediator] levels. Detection limits of PGE2, PGD2, CORT and IL-6 assays were 39.1-2500pg/mL, 19.5-2500pg/mL, 0.12-2000μg/dL, and 0.125-8ng/mL, respectively. We also assessed tail skin temperature [used to calculate heat loss index (HLI)] to assess a key thermoeffector mechanism. As expected we observed LPS-induced increases in Tb, AVPO PGE2 (whereas PGD2 remained unchanged), plasma CORT and IL-6 levels, as well as a decrease in HLI. These changes were accompanied by reduced levels of AVPO 5-HT and 5-HIAA. Furthermore, we also observed a negative correlation between 5-HT and plasma CORT levels. Moreover, icv 5-HT (5, 10 and 40μg/μL) microinjection caused a U-shaped dose-response curve in LPS fever, in which the intermediate dose reduced the febrile response. Icv 5-HT (10μg/μL) microinjection prevented the LPS-induced increases in AVPO PGE2 (whereas not altering PGD2), plasma CORT and IL-6 levels, as well as preventing reduced HLI. Our data are consistent with the notion that AVPO 5-HT synthesis is down-regulated during SI, favoring AVPO PGE2 synthesis and consequently potentiating the immune response. These results reveal a novel effect of central 5-HT as an anti-inflammatory neuromodulator that may take place during psychiatric disorder treatment with 5-HT reuptake inhibitors as well as suggesting that 5-HT modulation per se is a potential therapeutic approach for inflammatory diseases.
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Affiliation(s)
- Clarissa M D Mota
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Caroline Rodrigues-Santos
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Rodrigo A R Fernández
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Ruither O G Carolino
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - José Antunes-Rodrigues
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Janete A Anselmo-Franci
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Luiz G S Branco
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
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10
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Rakus K, Ronsmans M, Vanderplasschen A. Behavioral fever in ectothermic vertebrates. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 66:84-91. [PMID: 27381718 DOI: 10.1016/j.dci.2016.06.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 06/06/2023]
Abstract
Fever is an evolutionary conserved defense mechanism which is present in both endothermic and ectothermic vertebrates. Ectotherms in response to infection can increase their body temperature by moving to warmer places. This process is known as behavioral fever. In this review, we summarize the current knowledge on the mechanisms of induction of fever in mammals. We further discuss the evolutionary conserved mechanisms existing between fever of mammals and behavioral fever of ectothermic vertebrates. Finally, the experimental evidences supporting an adaptive value of behavioral fever expressed by ectothermic vertebrates are summarized.
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Affiliation(s)
- Krzysztof Rakus
- Department of Evolutionary Immunology, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland.
| | - Maygane Ronsmans
- Immunology-Vaccinology, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.
| | - Alain Vanderplasschen
- Immunology-Vaccinology, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.
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11
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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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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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Steiner AA, Romanovsky AA. Platelet-activating factor is a potent pyrogen and cryogen, but it does not mediate lipopolysaccharide fever or hypothermia. Temperature (Austin) 2015; 2:535-42. [PMID: 27227073 PMCID: PMC4843927 DOI: 10.1080/23328940.2015.1030540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 03/13/2015] [Accepted: 03/13/2015] [Indexed: 12/22/2022] Open
Abstract
We examined whether platelet-activating factor (PAF) and its receptor mediate lipopolysaccharide (LPS)-induced fever and hypothermia in rats. Two highly potent, structurally distinct antagonists of the PAF receptor, CV6209 and WEB2086, were used. At a neutral ambient temperature (Ta) of 30ºC, administration of LPS at a low (10 μg/kg, i.v.) or high (1,000 μg/kg, i.v.) dose resulted in fever. The response to the high dose was turned into hypothermia at a subneutral Ta of 22ºC. Neither LPS-induced fever nor hypothermia was affected by pretreatment with CV6209 (5 mg/kg, i.v.) or WEB2086 (5 mg/kg, i.v.). However, both PAF antagonists were efficacious in blocking the thermoregulatory response caused by PAF (334 pmol/kg/min, 1 h, i.v.), regardless of whether the response was a fever (at 30ºC) or hypothermia (at 22ºC). Additional experiments showed that the thermoregulatory responses to LPS and PAF are also distinct in terms of their mediation by prostaglandins. Neither PAF fever nor PAF hypothermia was affected by pretreatment with the cyclooxygenase-2 inhibitor SC236 (5 mg/kg, i.p.), which is known to abrogate LPS fever. The responses to PAF were also unaffected by pretreatment with the cyclooxygenase-1 inhibitor SC560 (5 mg/kg, i.p.), which is known to attenuate LPS hypothermia. In conclusion, PAF infusion at a picomolar dose causes fever at thermoneutrality but hypothermia in a subthermoneutral environment, both responses being dependent on the PAF receptor and independent of prostaglandins. However, the PAF receptor does not mediate LPS-induced fever or hypothermia, thus challenging the dogma that PAF is an upstream mediator of responses to LPS.
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Affiliation(s)
- Alexandre A Steiner
- Feverlab; Trauma Research; St. Joseph's Hospital and Medical Center; Phoenix, AZ USA; Department of Immunology; Institute of Biomedical Sciences; University of São Paulo; São Paulo, SP Brazil
| | - Andrej A Romanovsky
- Feverlab; Trauma Research; St. Joseph's Hospital and Medical Center ; Phoenix, AZ USA
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14
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Abstract
The heat shock response (HSR) is an ancient and highly conserved process that is essential for coping with environmental stresses, including extremes of temperature. Fever is a more recently evolved response, during which organisms temporarily subject themselves to thermal stress in the face of infections. We review the phylogenetically conserved mechanisms that regulate fever and discuss the effects that febrile-range temperatures have on multiple biological processes involved in host defense and cell death and survival, including the HSR and its implications for patients with severe sepsis, trauma, and other acute systemic inflammatory states. Heat shock factor-1, a heat-induced transcriptional enhancer is not only the central regulator of the HSR but also regulates expression of pivotal cytokines and early response genes. Febrile-range temperatures exert additional immunomodulatory effects by activating mitogen-activated protein kinase cascades and accelerating apoptosis in some cell types. This results in accelerated pathogen clearance, but increased collateral tissue injury, thus the net effect of exposure to febrile range temperature depends in part on the site and nature of the pathologic process and the specific treatment provided.
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Affiliation(s)
- Jeffrey D Hasday
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine and the Baltimore V.A. Medical Center, Baltimore, Maryland
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15
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Wanner SP, Yoshida K, Kulchitsky VA, Ivanov AI, Kanosue K, Romanovsky AA. Lipopolysaccharide-induced neuronal activation in the paraventricular and dorsomedial hypothalamus depends on ambient temperature. PLoS One 2013; 8:e75733. [PMID: 24069444 PMCID: PMC3777970 DOI: 10.1371/journal.pone.0075733] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 08/16/2013] [Indexed: 01/24/2023] Open
Abstract
Systemic inflammatory response syndrome is associated with either fever or hypothermia, but the mechanisms responsible for switching from one to the other are unknown. In experimental animals, systemic inflammation is often induced by bacterial lipopolysaccharide (LPS). To identify the diencephalic and brainstem structures involved in the fever-hypothermia switch, we studied the expression of c-Fos protein, a marker of neuronal activation, in rats treated with the same high dose of LPS (0.5 mg/kg, intravenously) either in a thermoneutral (30 °C) or cool (24 °C) environment. At 30 °C, LPS caused fever; at 24 °C, the same dose caused profound hypothermia. Both fever and hypothermia were associated with the induction of c-Fos in many brain areas, including several structures of the anterior preoptic, paraventricular, lateral, and dorsal hypothalamus, the bed nucleus of the stria terminalis, the posterior pretectal nucleus, ventrolateral periaqueductal gray, lateral parabrachial nucleus, area postrema, and nucleus of the solitary tract. Every brain area studied showed a comparable response to LPS at the two different ambient temperatures used, with the exception of two areas: the dorsomedial hypothalamic nucleus (DMH), which we studied together with the adjacent dorsal hypothalamic area (DA), and the paraventricular hypothalamic nucleus (PVH). Both structures had much stronger c-Fos expression during LPS hypothermia than during fever. We propose that PVH and DMH/DA neurons are involved in a circuit, which - depending on the ambient temperature - determines whether the thermoregulatory response to bacterial LPS will be fever or hypothermia.
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Affiliation(s)
- Samuel P. Wanner
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
- School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Kyoko Yoshida
- Department of Physiology, School of Allied Health Sciences, Faculty of Medicine, Osaka University, Osaka, Japan
| | - Vladimir A. Kulchitsky
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
- Institute of Physiology, National Academy of Sciences, Minsk, Belarus
| | - Andrei I. Ivanov
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
- Department of Human and Molecular Genetics and Virginia Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Kazuyuki Kanosue
- Department of Physiology, School of Allied Health Sciences, Faculty of Medicine, Osaka University, Osaka, Japan
- Graduate School of Sport Sciences, Waseda University, Tokorozawa, Japan
| | - Andrej A. Romanovsky
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
- Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, Arizona, United States of America
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Damm J, Harden LM, Gerstberger R, Roth J, Rummel C. The putative JAK-STAT inhibitor AG490 exacerbates LPS-fever, reduces sickness behavior, and alters the expression of pro- and anti-inflammatory genes in the rat brain. Neuropharmacology 2013; 71:98-111. [DOI: 10.1016/j.neuropharm.2013.03.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 02/28/2013] [Accepted: 03/18/2013] [Indexed: 11/26/2022]
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Saper CB, Romanovsky AA, Scammell TE. Neural circuitry engaged by prostaglandins during the sickness syndrome. Nat Neurosci 2012; 15:1088-95. [PMID: 22837039 DOI: 10.1038/nn.3159] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
During illnesses caused by infectious disease or other sources of inflammation, a suite of brain-mediated responses called the sickness syndrome occurs, which includes fever, anorexia, sleepiness, hyperalgesia and elevated corticosteroid secretion. Much of the sickness syndrome is mediated by prostaglandins acting on the brain and can be prevented by nonsteroidal anti-inflammatory drugs, such as aspirin or ibuprofen, that block prostaglandin synthesis. By examining which prostaglandins are produced at which sites and how they interact with the nervous system, researchers have identified specific neural circuits that underlie the sickness syndrome.
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Affiliation(s)
- Clifford B Saper
- Department of Neurology, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
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Yun CH, Kim JG, Park BS, Lee HM, Kim DH, Kim EO, Park JJ, Park JW, Damante G, Kim YI, Lee BJ. TTF-1 action on the transcriptional regulation of cyclooxygenase-2 gene in the rat brain. PLoS One 2011; 6:e28959. [PMID: 22174936 PMCID: PMC3236776 DOI: 10.1371/journal.pone.0028959] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 11/17/2011] [Indexed: 12/04/2022] Open
Abstract
We have recently found that thyroid transcription factor-1 (TTF-1), a homeodomain-containing transcription factor, is postnatally expressed in discrete areas of the hypothalamus and closely involved in neuroendocrine functions. We now report that transcription of cyclooxygenase-2 (COX-2), the rate limiting enzyme in prostaglandin biosynthesis, was inhibited by TTF-1. Double immunohistochemistry demonstrated that TTF-1 was expressed in the astrocytes and endothelial cells of blood vessel in the hypothalamus. Promoter assays and electrophoretic mobility shift assays showed that TTF-1 inhibited COX-2 transcription by binding to specific binding domains in the COX-2 promoter. Furthermore, blocking TTF-1 synthesis by intracerebroventricular injection of an antisense oligomer induced an increase of COX-2 synthesis in non-neuronal cells of the rat hypothalamus, and resulted in animals' hyperthermia. These results suggest that TTF-1 is physiologically involved in the control of thermogenesis by regulating COX-2 transcription in the brain.
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Affiliation(s)
- Chang Ho Yun
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
| | - Jae Geun Kim
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
| | - Byong Seo Park
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
| | - Hye Myeong Lee
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
| | - Dong Hee Kim
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
| | - Eun Ok Kim
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
| | - Joong Jean Park
- Department of Physiology, College of Medicine, Korea University, Seoul, South Korea
| | - Jeong Woo Park
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
| | - Giuseppe Damante
- Department of Biomedical Sciences and Technologies, University of Udine, Udine, Italy
| | - Young Il Kim
- Department of Internal Medicine, Ulsan University Hospital, Ulsan, South Korea
- * E-mail: (YIK); (BJL)
| | - Byung Ju Lee
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan, South Korea
- * E-mail: (YIK); (BJL)
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Abstract
Stress is a state of physiological or psychological strain caused by adverse stimuli; responses to stress include activation of the sympathetic nervous system, glucocorticoid secretion and emotional behaviors. Prostaglandin E(2) (PGE(2)), acting through its four receptor subtypes (EP1, EP2, EP3 and EP4), is involved in these stress responses. Studies of EP-selective drugs and mice lacking specific EPs have identified the neuronal pathways regulated by PGE(2). In animals with febrile illnesses, PGE(2) acts on neurons expressing EP3 in the preoptic hypothalamus. In illness-induced activation of the hypothalamic-pituitary-adrenal axis, EP1 and EP3 regulate distinct neuronal pathways that converge at the paraventricular hypothalamus. During psychological stress, EP1 suppresses impulsive behaviors via the midbrain dopaminergic systems. PGE(2) promotes illness-induced memory impairment, yet also supports hippocampus-dependent memory formation and synaptic plasticity via EP2 in physiological conditions. In response to illness, PGE(2) is synthesized by enzymes induced in various cell types inside and outside the brain, whereas constitutively expressed enzymes in neurons and/or microglia synthesize PGE(2) in response to psychological stress. Dependent on the type of stress stimuli, PGE(2) released from different cell types activates distinct EP receptors, which mobilize multiple neuronal pathways, resulting in stress responses.
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Affiliation(s)
- Tomoyuki Furuyashiki
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Yoshida-konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
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Gaetano L, Watanabe K, Barogi S, Coceani F. Cyclooxygenase-2/microsomal prostaglandin E synthase-1 complex in the preoptic-anterior hypothalamus of the mouse: involvement through fever to intravenous lipopolysaccharide. Acta Physiol (Oxf) 2010; 200:315-24. [PMID: 20587000 DOI: 10.1111/j.1748-1716.2010.02157.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
AIM Prostaglandin E₂ (PGE₂) is now well established as a central effector of pyrogen fever. However, questions remain on the source, local vs. blood-borne, of the compound for the early phase of the typically biphasic fever (Phases 1 and 2) to i.v. pyrogens. To verify the role of centrally formed PGE₂, we examined the cyclooxygenase (COX)/prostaglandin E synthase (PGES) complex through fever to i.v. lipopolysaccharide (LPS). METHODS Experiments were carried out in the conscious mouse and LPS effect was ascertained on all steps of expression - gene, protein, catalytic activity - of individual enzymes. The analysis was limited to the preoptic-anterior hypothalamus (AH/POA). RESULTS We found upregulation of the COX2 transcript together with an upward trend for the mPGES1 transcript during Phase 1. Coincidentally, there was a progressive increase in COX2 and mPGES1 protein expression through Phases 1 and 2. Catalytic activity for COX1 and COX2 combined was instead enhanced only in Phase 2, while mPGES1 activity remained steady at an intrinsically high level. Other COX and PGES enzymes were not modified through either Phase, and COX2/mPGES1 changes subsided with fever defervescence. CONCLUSION The findings confirm a key function of COX2 and mPGES1 for the synthesis of pyrogenic PGE₂ and, at the same time, document their early response to LPS. We conclude that locally formed PGE₂ in AH/POA is qualified for a role in the initiation of fever.
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Affiliation(s)
- L Gaetano
- Scuola Superiore Sant'Anna, Pisa, Italy
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21
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Krall CM, Yao X, Hass MA, Feleder C, Steiner AA. Food deprivation alters thermoregulatory responses to lipopolysaccharide by enhancing cryogenic inflammatory signaling via prostaglandin D2. Am J Physiol Regul Integr Comp Physiol 2010; 298:R1512-21. [PMID: 20393159 DOI: 10.1152/ajpregu.00158.2010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We tested the hypothesis that food deprivation alters body temperature (T(b)) responses to bacterial LPS by enhancing inflammatory signaling that decreases T(b) (cryogenic signaling) rather than by suppressing inflammatory signaling that increases T(b) (febrigenic signaling). Free-feeding or food-deprived (24 h) rats received LPS at doses (500 and 2,500 microg/kg iv) that are high enough to activate both febrigenic and cryogenic signaling. At these doses, LPS caused fever in rats at an ambient temperature of 30 degrees C, but produced hypothermia at an ambient temperature of 22 degrees C. Whereas food deprivation had little effect on LPS fever, it enhanced LPS hypothermia, an effect that was particularly pronounced in rats injected with the higher LPS dose. Enhancement of hypothermia was not due to thermogenic incapacity, since food-deprived rats were fully capable of raising T(b) in response to the thermogenic drug CL316,243 (1 mg/kg iv). Neither was enhancement of hypothermia associated with altered plasma levels of cytokines (TNF-alpha, IL-1beta, and IL-6) or with reduced levels of an anti-inflammatory hormone (corticosterone). The levels of PGD(2) and PGE(2) during LPS hypothermia were augmented by food deprivation, although the ratio between them remained unchanged. Food deprivation, however, selectively enhanced the responsiveness of rats to the cryogenic action of PGD(2) (100 ng icv) without altering the responsiveness to febrigenic PGE(2) (100 ng icv). These findings support our hypothesis and indicate that cryogenic signaling via PGD(2) underlies enhancement of LPS hypothermia by food deprivation.
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Affiliation(s)
- Catherine M Krall
- Department of Pharmaceutical Sciences, Albany College of Pharmacy & Health Sciences, Albany, NY 12208, USA
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22
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Steiner AA, Hunter JC, Phipps SM, Nucci TB, Oliveira DL, Roberts JL, Scheck AC, Simmons DL, Romanovsky AA. Cyclooxygenase-1 or -2--which one mediates lipopolysaccharide-induced hypothermia? Am J Physiol Regul Integr Comp Physiol 2009; 297:R485-94. [PMID: 19515980 DOI: 10.1152/ajpregu.91026.2008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Systemic inflammation is associated with either fever or hypothermia. Fever, a response to mild systemic inflammation, is mediated by cyclooxygenase (COX)-2 and not by COX-1. However, it is still disputed whether COX-2, COX-1, neither, or both mediate(s) responses to severe systemic inflammation, and, in particular, the hypothermic response. We compared the effects of SC-236 (COX-2 inhibitor) and SC-560 (COX-1 inhibitor) on the deep body temperature (T(b)) of rats injected with a lower (10 microg/kg i.v.) or higher (1,000 microg/kg i.v.) dose of LPS at different ambient temperatures (T(a)s). At a neutral T(a) (30 degrees C), the rats responded to LPS with a polyphasic fever (lower dose) or a brief hypothermia followed by fever (higher dose). SC-236 (2.5 mg/kg i.v.) blocked the fever induced by either LPS dose, whereas SC-560 (5 mg/kg i.v.) altered neither the febrile response to the lower LPS dose nor the fever component of the response to the higher dose. However, SC-560 blocked the initial hypothermia caused by the higher LPS dose. At a subneutral T(a) (22 degrees C), the rats responded to LPS with early (70-90 min, nadir) dose-dependent hypothermia. The hypothermic response to either dose was enhanced by SC-236 but blocked by SC-560. The hypothermic response to the higher LPS dose was associated with a fall in arterial blood pressure. This hypotensive response was attenuated by either SC-236 or SC-560. At the onset of LPS-induced hypothermia and hypotension, the functional activity of the COX-1 pathway (COX-1-mediated PGE(2) synthesis ex vivo) increased in the spleen but not liver, lung, kidney, or brain. The expression of splenic COX-1 was unaffected by LPS. We conclude that COX-1, but not COX-2, mediates LPS hypothermia, and that both COX isoforms are required for LPS hypotension.
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Affiliation(s)
- Alexandre A Steiner
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, 350 W. Thomas Road, Phoenix, AZ 85013, USA
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Havird JC, Miyamoto MM, Choe KP, Evans DH. Gene Duplications and Losses within the Cyclooxygenase Family of Teleosts and Other Chordates. Mol Biol Evol 2008; 25:2349-59. [DOI: 10.1093/molbev/msn183] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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MyD88 signaling in brain endothelial cells is essential for the neuronal activity and glucocorticoid release during systemic inflammation. Mol Psychiatry 2008; 13:480-97. [PMID: 18180766 DOI: 10.1038/sj.mp.4002122] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Activation of neuronal circuits involved in the control of autonomic responses is critical for the host survival to immune threats. The brain vascular system plays a key role in such immune-CNS communication, but the signaling pathway and exact type of cells within the blood-brain barrier (BBB) mediating these functions have yet to be uncovered. To elucidate this issue we used myeloid differentiation factor 88 (MyD88)-deficient mice, because these animals do not show any responses to the cytokine interleukin-1beta (IL-1beta). We created chimeric mice with competent MyD88 signaling in either the BBB endothelium or perivascular microglia of bone marrow origin and challenged them with IL-1beta. Systemic treatment with the cytokine caused a robust transcriptional activation of genes involved in the prostaglandin E(2) (PGE(2)) production by vascular cells of the brain. Upregulation of these genes is dependent on a functional MyD88 signaling in the endothelium, because MyD88-deficient mice that received bone marrow stem cells from wild-type animals (for example, functional perivascular microglia) exhibited no response to systemic IL-1beta administration. MyD88 competent endothelial cells also mediate neuronal activation and plasma release of glucocorticoids, whereas chimeric mice with MyD88-competent perivascular microglia did not show a significant increase of these functions. Moreover, competent endothelial cells for the gene encoding Toll-like receptor 4 (TLR4) are essential for the release of plasma corticosterone in response to low and high doses of lipopolysaccharide. Therefore, BBB endothelial cells and not perivascular microglia are the main target of circulating inflammatory mediators to activate the brain circuits and key autonomic functions during systemic immune challenges.
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Ootsuka Y, Blessing WW, Steiner AA, Romanovsky AA. Fever response to intravenous prostaglandin E2 is mediated by the brain but does not require afferent vagal signaling. Am J Physiol Regul Integr Comp Physiol 2008; 294:R1294-303. [DOI: 10.1152/ajpregu.00709.2007] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PGE2 produced in the periphery triggers the early phase of the febrile response to infection and may contribute to later phases. It can be hypothesized that peripherally synthesized PGE2 transmits febrigenic signals to the brain via vagal afferent nerves. Before testing this hypothesis, we investigated whether the febrigenic effect of intravenously administered PGE2 is mediated by the brain and is not the result of a direct action of PGE2 on thermoeffectors. In anesthetized rats, intravenously injected PGE2 (100 μg/kg) caused an increase in sympathetic discharge to interscapular brown adipose tissue (iBAT), as well as increases in iBAT thermogenesis, end-expired CO2, and colonic temperature (Tc). All these effects were prevented by inhibition of neuronal function in the raphe region of the medulla oblongata using an intra-raphe microinjection of muscimol. We then asked whether the brain-mediated PGE2 fever requires vagal signaling and answered this question by conducting two independent studies in rats. In a study in anesthetized rats, acute bilateral cervical vagotomy did not affect the effects of intravenously injected PGE2 (100 μg/kg) on iBAT sympathetic discharge and Tc. In a study in conscious rats, administration of PGE2 (280 μg/kg) via an indwelling jugular catheter caused tail skin vasoconstriction, tended to increase oxygen consumption, and increased Tc; none of these responses was affected by total truncal subdiaphragmatic vagotomy performed 2 wk before the experiment. We conclude that the febrile response to circulating PGE2 is mediated by the brain, but that it does not require vagal afferent signaling.
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Voss T, Barth SW, Rummel C, Gerstberger R, Hübschle T, Roth J. STAT3 and COX-2 activation in the guinea-pig brain during fever induced by the Toll-like receptor-3 agonist polyinosinic:polycytidylic acid. Cell Tissue Res 2007; 328:549-61. [PMID: 17345100 DOI: 10.1007/s00441-007-0386-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Accepted: 01/26/2007] [Indexed: 01/09/2023]
Abstract
Intra-arterial injections of synthetic double-stranded RNA (polyinosinic:polycytidylic acid, PIPC) at a dose of 500 microg/kg evoked pronounced fever in guinea-pigs. PIPC-induced fever could be antagonized by treatment with the non-selective cyclooxygenase (COX) inhibitor diclofenac and was, in part, attenuated by the administration of the selective COX-2-inhibitor nimesulide (dose: 5 mg/kg for both COX inhibitors). We further investigated whether direct activation of brain cells during PIPC-induced fever could be demonstrated. Using radioactive in situ hybridization, we demonstrated that treatment with PIPC resulted in an upregulation of COX-2 and interleukin-1 beta mRNA in the guinea-pig brain. Thus, COX-2-specific hybridization signals seemed to be mainly associated with brain blood vessels. Intra-arterial injections of PIPC further induced the pronounced nuclear translocation of the transcription factor STAT3 in the endothelium of various fore- and hindbrain areas and in the meninges. In brain structures that lacked a tight blood-brain barrier, i.e. the sensory circumventricular organs (area postrema, vascular organ of laminae terminalis, subfornical organ), the astrocytes and a population of still undetermined cellular phenotype also showed marked STAT3 activation in response to PIPC. The Toll-like receptor-3 agonist PIPC therefore caused a similar activation of brain cells as that reported for other experimental models of systemic inflammation.
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Affiliation(s)
- Thilo Voss
- Institut für Veterinär-Physiologie, Justus-Liebig-Universität Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
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Romanovsky AA. Thermoregulation: some concepts have changed. Functional architecture of the thermoregulatory system. Am J Physiol Regul Integr Comp Physiol 2007; 292:R37-46. [PMID: 17008453 DOI: 10.1152/ajpregu.00668.2006] [Citation(s) in RCA: 415] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
While summarizing the current understanding of how body temperature (Tb) is regulated, this review discusses the recent progress in the following areas: central and peripheral thermosensitivity and temperature-activated transient receptor potential (TRP) channels; afferent neuronal pathways from peripheral thermosensors; and efferent thermoeffector pathways. It is proposed that activation of temperature-sensitive TRP channels is a mechanism of peripheral thermosensitivity. Special attention is paid to the functional architecture of the thermoregulatory system. The notion that deep Tb is regulated by a unified system with a single controller is rejected. It is proposed that Tb is regulated by independent thermoeffector loops, each having its own afferent and efferent branches. The activity of each thermoeffector is triggered by a unique combination of shell and core Tbs. Temperature-dependent phase transitions in thermosensory neurons cause sequential activation of all neurons of the corresponding thermoeffector loop and eventually a thermoeffector response. No computation of an integrated Tb or its comparison with an obvious or hidden set point of a unified system is necessary. Coordination between thermoeffectors is achieved through their common controlled variable, Tb. The described model incorporates Kobayashi’s views, but Kobayashi’s proposal to eliminate the term sensor is rejected. A case against the term set point is also made. Because this term is historically associated with a unified control system, it is more misleading than informative. The term balance point is proposed to designate the regulated level of Tb and to attract attention to the multiple feedback, feedforward, and open-loop components that contribute to thermal balance.
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Affiliation(s)
- Andrej A Romanovsky
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, USA.
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Dimicco JA, Zaretsky DV. The dorsomedial hypothalamus: a new player in thermoregulation. Am J Physiol Regul Integr Comp Physiol 2007; 292:R47-63. [PMID: 16959861 DOI: 10.1152/ajpregu.00498.2006] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neurons in the dorsomedial hypothalamus (DMH) play key roles in physiological responses to exteroceptive (“emotional”) stress in rats, including tachycardia. Tachycardia evoked from the DMH or seen in experimental stress in rats is blocked by microinjection of the GABAA receptor agonist muscimol into the rostral raphe pallidus (rRP), an important thermoregulatory site in the brain stem, where disinhibition elicits sympathetically mediated activation of brown adipose tissue (BAT) and cutaneous vasoconstriction in the tail. Disinhibition of neurons in the DMH also elevates core temperature in conscious rats and sympathetic activity to least significant difference interscapular BAT (IBAT) and IBAT temperature in anesthetized preparations. The latter effects are blocked by microinjection of muscimol into the rRP, while microinjection of muscimol into either the rRP or DMH suppresses increases in sympathetic nerve activity to IBAT, IBAT temperature, and core body temperature elicited either by microinjection of PGE2 into the preoptic area (an experimental model for fever), or central administration of fentanyl. Neurons concentrated in the dorsal region of the DMH project directly to the rRP, a location corresponding to that of neurons transsynaptically labeled from IBAT. Thus these neurons control nonshivering thermogenesis in rats, and their activation signals its recruitment in diverse experimental paradigms. Evidence also points to a role for neurons in the DMH in thermoregulatory cutaneous vasoconstriction, shivering, and endocrine adjustments. These directions provide intriguing avenues for future exploration that may expand our understanding of the DMH as an important hypothalamic site for the integration of autonomic, endocrine, and behavioral responses to diverse challenges.
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Affiliation(s)
- Joseph A Dimicco
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Steiner AA, Ivanov AI, Serrats J, Hosokawa H, Phayre AN, Robbins JR, Roberts JL, Kobayashi S, Matsumura K, Sawchenko PE, Romanovsky AA. Cellular and molecular bases of the initiation of fever. PLoS Biol 2006; 4:e284. [PMID: 16933973 PMCID: PMC1551923 DOI: 10.1371/journal.pbio.0040284] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Accepted: 06/21/2006] [Indexed: 02/02/2023] Open
Abstract
All phases of lipopolysaccharide (LPS)-induced fever are mediated by prostaglandin (PG) E2. It is known that the second febrile phase (which starts at ~1.5 h post-LPS) and subsequent phases are mediated by PGE2 that originated in endotheliocytes and perivascular cells of the brain. However, the location and phenotypes of the cells that produce PGE2 triggering the first febrile phase (which starts at ~0.5 h) remain unknown. By studying PGE2 synthesis at the enzymatic level, we found that it was activated in the lung and liver, but not in the brain, at the onset of the first phase of LPS fever in rats. This activation involved phosphorylation of cytosolic phospholipase A2 (cPLA2) and transcriptional up-regulation of cyclooxygenase (COX)-2. The number of cells displaying COX-2 immunoreactivity surged in the lung and liver (but not in the brain) at the onset of fever, and the majority of these cells were identified as macrophages. When PGE2 synthesis in the periphery was activated, the concentration of PGE2 increased both in the venous blood (which collects PGE2 from tissues) and arterial blood (which delivers PGE2 to the brain). Most importantly, neutralization of circulating PGE2 with an anti-PGE2 antibody both delayed and attenuated LPS fever. It is concluded that fever is initiated by circulating PGE2 synthesized by macrophages of the LPS-processing organs (lung and liver) via phosphorylation of cPLA2 and transcriptional up-regulation of COX-2. Whether PGE2 produced at the level of the blood–brain barrier also contributes to the development of the first phase remains to be clarified. The authors show that peripherally-produced COX2 plays an important role in the earliest stages of fever.
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Affiliation(s)
- Alexandre A Steiner
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
| | - Andrei I Ivanov
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Jordi Serrats
- Laboratory of Neuronal Structure and Function, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Hiroshi Hosokawa
- Department of Intelligence Science and Technology, Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | - Allison N Phayre
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
| | - Jared R Robbins
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
| | - Jennifer L Roberts
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
| | - Shigeo Kobayashi
- Department of Intelligence Science and Technology, Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | | | - Paul E Sawchenko
- Laboratory of Neuronal Structure and Function, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Andrej A Romanovsky
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
- * To whom correspondence should be addressed. E-mail:
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Persson PB. Temperature control: from molecular insights, regulation in king penguins and diving seals, to studies in humans. Am J Physiol Regul Integr Comp Physiol 2006. [DOI: 10.1152/ajpregu.00315.2006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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