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Amorim MR, Moreira DA, Santos BM, Ferrari GD, Nogueira JE, de Deus JL, Alberici LC, Branco LGS. Increased lipopolysaccharide-induced hypothermia in neurogenic hypertension is caused by reduced hypothalamic PGE 2 production and increased heat loss. J Physiol 2020; 598:4663-4680. [PMID: 32749717 DOI: 10.1113/jp280321] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 07/31/2020] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS The mechanisms involved in hypothermia and fever during systemic inflammation (SI) remain largely unknown. Our data support the contention that brain-mediated mechanisms are different in hypertension during SI. Considering that, clinically, it is not easy to assess all mechanisms involved in cardiovascular and thermoregulatory control during SI, the present study sheds light on these integrated mechanisms that may be triggered simultaneously in septic hypertensive patients. The result obtained demonstrate that, in lipopolysaccharide-induced SI, an increased hypothermia is observed in neurogenic hypertension, which is caused by reduced hypothalamic prostaglandin E2 production and increased heat loss in conscious rats. Therefore, the results of the present study provide useful insight for clinical trials evaluating the thermoregulatory outcomes of septic patients with hypertension. ABSTRACT Hypertension is a prevalent disease characterized by autonomic-induced elevated and sustained blood pressure levels and abnormal body core temperature (Tb) regulation. The present study aimed to determine the brain-mediated mechanisms involved in the thermoregulatory changes observed during lipopolysaccharide (LPS)-induced systemic inflammation (SI; at a septic-like model) in spontaneously hypertensive rats (SHR). We combined Tb and skin temperature (Tsk) analysis, assessment of prostaglandin (PG) E2 levels (the proximal mediator of fever) in the anteroventral region of the hypothalamus (AVPO; an important site for Tb control), oxygen consumption analysis, cardiovascular recordings, assays of inflammatory markers, and evaluation of oxidative stress in the plasma and brain of male Wistar rats and SHR that had received LPS (1.5 mg kg-1 ) or saline. LPS induced hypothermia followed by fever in Wistar rats, whereas, in SHR, a maintained hypothermia without fever were observed. These thermoregulatory responses were associated with an increased heat loss in SHR compared to Wistar rats. We measured LPS-induced increased PGE2 levels in the AVPO in Wistar rats, but not in SHR. The LPS-induced drop in blood pressure was higher in SHR than in Wistar rats. Furthermore, LPS-induced plasma and brain [regions involved in autonomic control: nucleus tractus solitarius (NTS) and rostral ventrolateral medulla (RVLM)] cytokine surges were blunted, whereas oxidative stress was higher in SHR. LPS-induced SI leads to blunted cytokine surges both systemically (plasma) and centrally (NTS and RVLM) and reduced hypothalamic PGE2 production, which are all associated with increased hypothermia mediated by increased heat loss, but not by heat production, in SHR.
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Affiliation(s)
- Mateus R Amorim
- Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.,Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Diego A Moreira
- Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Bruna M Santos
- Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Gustavo D Ferrari
- Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.,Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jonatas E Nogueira
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Júnia L de Deus
- Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.,The Solomon H. Snyder. Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Luciane C Alberici
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luiz G S Branco
- Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Vliegen G, Kehoe K, Bracke A, De Hert E, Verkerk R, Fransen E, Jongers B‘, Peters E, Lambeir AM, Kumar-Singh S, Pickkers P, Jorens PG, De Meester I. Dysregulated activities of proline-specific enzymes in septic shock patients (sepsis-2). PLoS One 2020; 15:e0231555. [PMID: 32315321 PMCID: PMC7173796 DOI: 10.1371/journal.pone.0231555] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 03/25/2020] [Indexed: 02/07/2023] Open
Abstract
The proline-specific enzymes dipeptidyl peptidase 4 (DPP4), prolylcarboxypeptidase (PRCP), fibroblast activation protein α (FAP) and prolyl oligopeptidase (PREP) are known for their involvement in the immune system and blood pressure regulation. Only very limited information is currently available on their enzymatic activity and possible involvement in patients with sepsis and septic-shock. The activity of the enzymes was measured in EDTA-plasma of patients admitted to the intensive care unit (ICU): 40 septic shock patients (sepsis-2) and 22 ICU control patients after major intracranial surgery. These data were used to generate receiver operating characteristic (ROC) curves. A survival analysis (at 90 days) and an association study with other parameters was performed. PRCP (day 1) and PREP (all days) enzymatic activities were higher in septic shock patients compared to controls. In contrast, FAP and DPP4 were lower in these patients on all studied time points. Since large differences were found, ROC curves were generated and these yielded area under the curve (AUC) values for PREP, FAP and DPP4 of 0.88 (CI: 0.80-0.96), 0.94 (CI: 0.89-0.99) and 0.86 (CI: 0.77-0.95), respectively. PRCP had a lower predicting value with an AUC of 0.71 (CI: 0.58-0.83). A nominally significant association was observed between survival and the DPP4 enzymatic activity at day 1 (p<0.05), with a higher DPP4 activity being associated with an increase in survival. All four enzymes were dysregulated in septic shock patients. DPP4, FAP and PREP are good in discriminating between septic shock patients and ICU controls and should be further explored to see whether they are already dysregulated in earlier stages, opening perspectives for their further investigation as biomarkers in sepsis. DPP4 also shows potential as a prognostic biomarker. Additionally, the associations found warrant further research.
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Affiliation(s)
- Gwendolyn Vliegen
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Kaat Kehoe
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - An Bracke
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Emilie De Hert
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Robert Verkerk
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Erik Fransen
- StatUa Center for Statistics, University of Antwerp, Antwerp, Belgium
| | - Bart ‘s Jongers
- Molecular Pathology Group, Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - Esther Peters
- Department of Intensive Care Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Anne-Marie Lambeir
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Samir Kumar-Singh
- Molecular Pathology Group, Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - Peter Pickkers
- Department of Intensive Care Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Philippe G. Jorens
- Department of Critical Care Medicine, Antwerp University Hospital, Edegem, Belgium and Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Antwerp, Belgium
| | - Ingrid De Meester
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
- * E-mail:
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Wittrisch S, Klöting N, Mörl K, Chakaroun R, Blüher M, Beck-Sickinger AG. NPY 1R-targeted peptide-mediated delivery of a dual PPARα/γ agonist to adipocytes enhances adipogenesis and prevents diabetes progression. Mol Metab 2019; 31:163-180. [PMID: 31918918 PMCID: PMC6931124 DOI: 10.1016/j.molmet.2019.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/31/2019] [Accepted: 11/10/2019] [Indexed: 12/12/2022] Open
Abstract
Objective PPARα/γ dual agonists have been in clinical development for the treatment of metabolic diseases including type 2 diabetes and dyslipidemia. However, severe adverse side effects led to complications in clinical trials. As most of the beneficial effects rely on the compound activity in adipocytes, the selective targeting of this cell type is a cutting-edge strategy to develop safe anti-diabetic drugs. The goal of this study was to strengthen the adipocyte-specific uptake of the PPARα/γ agonist tesaglitazar via NPY1R-mediated internalization. Methods NPY1R-preferring peptide tesaglitazar-[F7, P34]-NPY (tesa-NPY) was synthesized by a combination of automated SPPS and manual couplings. Following molecular and functional analyses for proof of concept, cell culture experiments were conducted to monitor the effects on adipogenesis. Mice treated with peptide drug conjugates or vehicle either by gavage or intraperitoneal injection were characterized phenotypically and metabolically. Histological analysis and transcriptional profiling of the adipose tissue were performed. Results In vitro studies revealed that the tesaglitazar-[F7, P34]-NPY conjugate selectively activates PPARγ in NPY1R-expressing cells and enhances adipocyte differentiation and adiponectin expression in adipocyte precursor cells. In vivo studies using db/db mice demonstrated that the anti-diabetic activity of the peptide conjugate is as efficient as that of systemically administered tesaglitazar. Additionally, tesa-NPY induces adipocyte differentiation in vivo. Conclusions The use of the tesaglitazar-[F7, P34]-NPY conjugate is a promising strategy to apply the beneficial PPARα/γ effects in adipocytes while potentially omitting adverse effects in other tissues. Tesaglitazar-NPY targets adipocytes via NPY1R receptor-mediated internalization. Peptide-drug conjugate is specifically delivered to NPY1R-expressing cells. Release of tesaglitazar in adipocytes activates PPARγ. Drug delivery enhances adipocyte differentiation and adiponectin expression. Peptide conjugate exhibits antidiabetic activity in vivo.
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Affiliation(s)
- Stefanie Wittrisch
- Universität Leipzig, Institute of Biochemistry, Brüderstraße 34, 04103 Leipzig, Germany
| | - Nora Klöting
- Helmholtz Institute for Metabolic, Obesity, and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Ph.-Rosenthal-Str. 27, 04103 Leipzig, Germany.
| | - Karin Mörl
- Universität Leipzig, Institute of Biochemistry, Brüderstraße 34, 04103 Leipzig, Germany
| | - Rima Chakaroun
- Helmholtz Institute for Metabolic, Obesity, and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Ph.-Rosenthal-Str. 27, 04103 Leipzig, Germany; Department of Medicine, University of Leipzig, Liebigstraße 20, 04103 Leipzig, Germany
| | - Matthias Blüher
- Helmholtz Institute for Metabolic, Obesity, and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Ph.-Rosenthal-Str. 27, 04103 Leipzig, Germany; Department of Medicine, University of Leipzig, Liebigstraße 20, 04103 Leipzig, Germany.
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Makowska K, Mikolajczyk A, Calka J, Gonkowski S. Neurochemical characterization of nerve fibers in the porcine gallbladder wall under physiological conditions and after the administration of Salmonella enteritidis lipopolysaccharides (LPS). Toxicol Res (Camb) 2018; 7:73-83. [PMID: 30090564 PMCID: PMC6062139 DOI: 10.1039/c7tx00211d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/24/2017] [Indexed: 12/26/2022] Open
Abstract
Lipopolysaccharides (LPS, bacterial endotoxin) are a component of the cellular membrane of Gram-negative bacteria, which is known as an important pathological factor. In spite of many previous studies describing multidirectional negative effects of LPS on living organisms, the knowledge concerning the influence of bacterial endotoxins on the gallbladder innervation is extremely scarce. The present study, based on the immunofluorescence technique, describes the changes in the neurochemical characterization of nerves within various parts of the porcine gallbladder (neck, body and fundus) after the administration of low doses of LPS. The obtained results show that even low doses of bacterial endotoxins affect the nerve structures within the gallbladder wall and the intensity of fluctuations in immunoreactivity to particular substances clearly depends on the part of the investigated organ. The most evident changes were observed in the case of fibers exhibiting the presence of neuropeptide Y (an increase from 7.84 ± 0.17 to 14.66 ± 0.37) in the neck, substance P (an increase from 0.88 ± 0.1 to 8.4 ± 0.3) in the body and the vesicular acetylocholine transporter in the gallbladder's fundus (an increase from 4.29 ± 0.18 to 11.01 ± 0.26). The mechanisms of the observed changes still remain unclear, but probably they are connected with the pro-inflammatory and/or neurodegenerative activity of LPS.
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Affiliation(s)
- Krystyna Makowska
- Departement of Clinical Physiology , Faculty of Veterinary Medicine University of Warmia and Mazury in Olsztyn , Poland .
| | - Anita Mikolajczyk
- Department of Public Health , Epidemiology and Microbiology , Faculty of Medical Sciences University of Warmia and Mazury in Olsztyn , Poland
| | - Jaroslaw Calka
- Departement of Clinical Physiology , Faculty of Veterinary Medicine University of Warmia and Mazury in Olsztyn , Poland .
| | - Slawomir Gonkowski
- Departement of Clinical Physiology , Faculty of Veterinary Medicine University of Warmia and Mazury in Olsztyn , Poland .
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5
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Mikołajczyk A, Gonkowski S, Złotkowska D. Modulation of the main porcine enteric neuropeptides by a single low-dose of lipopolysaccharide (LPS) Salmonella Enteritidis. Gut Pathog 2017; 9:73. [PMID: 29255488 PMCID: PMC5727943 DOI: 10.1186/s13099-017-0225-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 12/06/2017] [Indexed: 12/31/2022] Open
Abstract
Background The present research was conducted to investigate the influence of a low, single dose of LPS, which does not result in any clinical symptoms of intoxication on the expression of selected neuropeptides within the intestines of the domestic pig. Methods This experiment was conducted on immature female pigs of the Pitrain × Duroc breed (n = five per group). Seven days after the intravenous injection of 10 mL saline solution for control animals and 5 μg/kg b.w. (in 10 mL saline solution) LPS Salmonella Enteritidis for the experimental group, the excised segments of duodenum, jejunum, ileum, ileocecal valve, caecum, descending colon, transverse colon, ascending colon and rectum were prepared to extract the main enteric neuropeptides, including GAL, NPY, SOM, SP, VIP. Results The results of this research indicate that single low-dose LPS S. Enteritidis produced changes in the content of the selected neuropeptides of the porcine intestine. The most visible changes were observed in the transverse colon, where LPS induced the increase of GAL expression from 19.41 ± 7.121 to 92.92 ± 11.447 ng/g tissue. Conclusion The exact functions of the substances studied and mechanisms of responses to LPS action depend on the sections of the intestines. The mechanisms of observed changes are not fully understood, but fluctuations in neuronal active substance levels may be connected with neurodegenerative and/or pro-inflammatory activity of LPS.
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Affiliation(s)
- Anita Mikołajczyk
- Department of Public Health, Epidemiology and Microbiology, Faculty of Health Sciences, University of Warmia and Mazury in Olsztyn, ul. Warszawska 30 Str., 10-082 Olsztyn, Poland
| | - Sławomir Gonkowski
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13 Str., 10-718 Olsztyn, Poland
| | - Dagmara Złotkowska
- Department of Food Immunology and Microbiology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, Tuwima 10 Str., 10-748 Olsztyn, Poland
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Dawson DG, Bower KA, Burnette CN, Holt RK, Swearengen JR, Dabisch PA, Scorpio A. Using Telemetry Data to Refine Endpoints for New Zealand White Rabbits Challenged with Bacillus anthracis. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2017; 56:792-801. [PMID: 29256375 PMCID: PMC5710159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 08/07/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
We used a continuous-monitoring digital telemetry system to investigate temperature response in New Zealand White rabbits after inhalation or subcutaneous challenge with Bacillus anthracis. Two spore preparations of B. anthracis Ames A2084 were evaluated by using a nose-only inhalation model, and 2 strains, B. anthracis Ames A2084 and B. anthracis UT500, were evaluated in a subcutaneous model. Animal body temperature greater than 3 SD above the mean baseline temperature was considered a significant increase in body temperature (SIBT). All rabbits that exhibited SIBT after challenge by either route of infection or bacterial strain eventually died or were euthanized due to infection, and all rabbits that died or were euthanized due to infection exhibited SIBT during the course of disease. The time at onset of SIBT preceded clinical signs of disease in 94% of the rabbits tested by as long as 2 days. In addition, continuous temperature monitoring facilitated discrimination between the 2 B. anthracis strains with regard to the time interval between SIBT and death. These data suggest that for the New Zealand White rabbit anthrax model, SIBT is a reliable indicator of infection, is predictive of experimental outcome in the absence of treatment, and is measurable prior to the appearance of more severe signs of disease. The use of digital telemetry to monitor infectious disease course in animal models of anthrax can potentially be used in conjunction with other clinical score metrics to refine endpoint euthanasia criteria.
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Affiliation(s)
- David G Dawson
- National Biological Threat Characterization Center, National Biodefense Analysis and Countermeasures Center, Frederick, Maryland
| | - Kristin A Bower
- National Biological Threat Characterization Center, National Biodefense Analysis and Countermeasures Center, Frederick, Maryland
| | - Candace N Burnette
- National Biological Threat Characterization Center, National Biodefense Analysis and Countermeasures Center, Frederick, Maryland
| | - Rebecca K Holt
- National Biological Threat Characterization Center, National Biodefense Analysis and Countermeasures Center, Frederick, Maryland
| | - James R Swearengen
- National Biological Threat Characterization Center, National Biodefense Analysis and Countermeasures Center, Frederick, Maryland
| | - Paul A Dabisch
- National Biological Threat Characterization Center, National Biodefense Analysis and Countermeasures Center, Frederick, Maryland
| | - Angelo Scorpio
- National Biological Threat Characterization Center, National Biodefense Analysis and Countermeasures Center, Frederick, Maryland;,
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Ye H, Yang Z, Li H, Gao Z. NPY binds with heme to form a NPY–heme complex: enhancing peroxidase activity in free heme and promoting NPY nitration and inactivation. Dalton Trans 2017; 46:10315-10323. [DOI: 10.1039/c7dt01822c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
NPY binding with heme enhances the peroxidase activity of free heme, resulting in the important tyrosine nitration, which will attenuate its bioactivity.
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Affiliation(s)
- Huixian Ye
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica
| | - Zhen Yang
- Department of Chemical and Biomolecular Engineering
- University of Houston
- Houston
- USA
| | - Hailing Li
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica
| | - Zhonghong Gao
- School of Chemistry and Chemical Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica
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Hao L, Sheng Z, Potian J, Deak A, Rohowsky-Kochan C, Routh VH. Lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFα) blunt the response of Neuropeptide Y/Agouti-related peptide (NPY/AgRP) glucose inhibited (GI) neurons to decreased glucose. Brain Res 2016; 1648:181-192. [PMID: 27473896 DOI: 10.1016/j.brainres.2016.07.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 07/18/2016] [Accepted: 07/19/2016] [Indexed: 02/07/2023]
Abstract
A population of Neuropeptide Y (NPY) neurons which co-express Agouti-related peptide (AgRP) in the arcuate nucleus of the hypothalamus (ARC) are inhibited at physiological levels of brain glucose and activated when glucose levels decline (e.g. glucose-inhibited or GI neurons). Fasting enhances the activation of NPY/AgRP-GI neurons by low glucose. In the present study we tested the hypothesis that lipopolysaccharide (LPS) inhibits the enhanced activation of NPY/AgRP-GI neurons by low glucose following a fast. Mice which express green fluorescent protein (GFP) on their NPY promoter were used to identify NPY/AgRP neurons. Fasting for 24h and LPS injection decreased blood glucose levels. As we have found previously, fasting increased c-fos expression in NPY/AgRP neurons and increased the activation of NPY/AgRP-GI neurons by decreased glucose. As we predicted, LPS blunted these effects of fasting at the 24h time point. Moreover, the inflammatory cytokine tumor necrosis factor alpha (TNFα) blocked the activation of NPY/AgRP-GI neurons by decreased glucose. These data suggest that LPS and TNFα may alter glucose and energy homeostasis, in part, due to changes in the glucose sensitivity of NPY/AgRP neurons. Interestingly, our findings also suggest that NPY/AgRP-GI neurons use a distinct mechanism to sense changes in extracellular glucose as compared to our previous studies of GI neurons in the adjacent ventromedial hypothalamic nucleus.
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Affiliation(s)
- Lihong Hao
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA; Graduate School of the Biomedical Sciences, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Zhenyu Sheng
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Joseph Potian
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Adam Deak
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Christine Rohowsky-Kochan
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Vanessa H Routh
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA.
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Clausen T. Excitation of skeletal muscle is a self-limiting process, due to run-down of Na+, K+ gradients, recoverable by stimulation of the Na+, K+ pumps. Physiol Rep 2015; 3:3/4/e12373. [PMID: 25862098 PMCID: PMC4425977 DOI: 10.14814/phy2.12373] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The general working hypothesis of this study was that muscle fatigue and force recovery depend on passive and active fluxes of Na+ and K+. This is tested by examining the time-course of excitation-induced fluxes of Na+ and K+ during 5–300 sec of 10–60 Hz continuous electrical stimulation in rat extensor digitorum longus (EDL) muscles in vitro and in vivo using 22Na and flame photometric determination of Na+ and K+. 60 sec of 60 Hz stimulation rapidly increases 22Na influx, during the initial phase (0–15 sec) by 0.53 μmol(sec)−1(g wet wt.)−1, sixfold faster than in the later phase (15–60 sec). These values agree with flame photometric measurements of Na+ content. The progressive reduction in the rate of excitation-induced Na+ uptake is likely to reflect gradual loss of excitability due to accumulation of K+ in the extracellular space and t-tubules leading to depolarization. This is in keeping with the concomitant progressive loss of contractile force previously demonstrated. During electrical stimulation rat muscles rapidly reach high rates of active Na+, K+-transport (in EDL muscles a sevenfold increase and in soleus muscles a 22-fold increase), allowing efficient and selective compensation for the large excitation-induced passive Na+, K+-fluxes demonstrated over the latest decades. The excitation-induced changes in passive fluxes of Na+ and K+ are both clearly larger than previously observed. The excitation-induced reduction in [Na+]o contributes considerably to the inhibitory effect of elevated [K+]o. In conclusion, excitation-induced passive and active Na+ and K+ fluxes are important causes of muscle fatigue and force recovery, respectively.
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Affiliation(s)
- Torben Clausen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
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10
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Farzi A, Reichmann F, Holzer P. The homeostatic role of neuropeptide Y in immune function and its impact on mood and behaviour. Acta Physiol (Oxf) 2015; 213:603-27. [PMID: 25545642 DOI: 10.1111/apha.12445] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/10/2014] [Accepted: 12/21/2014] [Indexed: 12/18/2022]
Abstract
Neuropeptide Y (NPY), one of the most abundant peptides in the nervous system, exerts its effects via five receptor types, termed Y1, Y2, Y4, Y5 and Y6. NPY's pleiotropic functions comprise the regulation of brain activity, mood, stress coping, ingestion, digestion, metabolism, vascular and immune function. Nerve-derived NPY directly affects immune cells while NPY also acts as a paracrine and autocrine immune mediator, because immune cells themselves are capable of producing and releasing NPY. NPY is able to induce immune activation or suppression, depending on a myriad of factors such as the Y receptors activated and cell types involved. There is an intricate relationship between psychological stress, mood disorders and the immune system. While stress represents a risk factor for the development of mood disorders, it exhibits diverse actions on the immune system as well. Conversely, inflammation is regarded as an internal stressor and is increasingly recognized to contribute to the pathogenesis of mood and metabolic disorders. Intriguingly, the cerebral NPY system has been found to protect against distinct disturbances in response to immune challenge, attenuating the sickness response and preventing the development of depression. Thus, NPY plays an important homeostatic role in balancing disturbances of physiological systems caused by peripheral immune challenge. This implication is particularly evident in the brain in which NPY counteracts the negative impact of immune challenge on mood, emotional processing and stress resilience. NPY thus acts as a unique signalling molecule in the interaction of the immune system with the brain in health and disease.
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Affiliation(s)
- A. Farzi
- Research Unit of Translational Neurogastroenterology; Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - F. Reichmann
- Research Unit of Translational Neurogastroenterology; Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
| | - P. Holzer
- Research Unit of Translational Neurogastroenterology; Institute of Experimental and Clinical Pharmacology; Medical University of Graz; Graz Austria
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11
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Radler ME, Wright BJ, Walker FR, Hale MW, Kent S. Calorie restriction increases lipopolysaccharide-induced neuropeptide Y immunolabeling and reduces microglial cell area in the arcuate hypothalamic nucleus. Neuroscience 2014; 285:236-47. [PMID: 25446356 DOI: 10.1016/j.neuroscience.2014.11.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/20/2014] [Accepted: 11/04/2014] [Indexed: 11/30/2022]
Abstract
Calorie restriction (CR) increases longevity and elicits many health promoting benefits including delaying immunosenescence and reducing the incidence of age-related diseases. Although the mechanisms underlying the health-enhancing effects of CR are not known, a likely contributing factor is alterations in immune system functioning. CR suppresses lipopolysaccharide (LPS)-induced release of pro-inflammatory cytokines, blocks LPS-induced fever, and shifts hypothalamic signaling pathways to an anti-inflammatory bias. Furthermore, we have recently shown that CR attenuates LPS-stimulated microglial activation in the hypothalamic arcuate nucleus (ARC), a brain region containing neurons that synthesize neuropeptide Y (NPY), an orexigenic neuropeptide that is upregulated by a CR diet and has anti-inflammatory properties. To determine if increased NPY expression in the ARC following CR was associated with changes in microglial activation, a set of brain sections from mice that were exposed to 50% CR or ad libitum feeding for 28 days before being injected with LPS were immunostained for NPY. The density of NPY-immunolabeling was assessed across the rostrocaudal extent of the ARC and hypothalamic paraventricular nucleus (PVN). An adjacent set of sections were immunostained for ionized calcium-binding adapter molecule-1 (Iba1) and immunostained microglia in the ARC were digitally reconstructed to investigate the effects of CR on microglial morphology. We demonstrated that exposure to CR increased NPY expression in the ARC, but not the PVN. Digital reconstruction of microglia revealed that LPS increased Iba1 intensity in ad libitum fed mice but had no effect on Iba1 intensity in CR mice. CR also decreased the size of ARC microglial cells following LPS. Correlational analyses revealed strong associations between NPY and body temperature, and body temperature and microglia area. Together these results suggest that CR-induced changes in NPY are not directly involved in the suppression of LPS-induced microglial activation, however, NPY may indirectly affect microglial morphology through changes in body temperature.
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Affiliation(s)
- M E Radler
- School of Psychological Science, La Trobe University, Melbourne, VIC, Australia
| | - B J Wright
- School of Psychological Science, La Trobe University, Melbourne, VIC, Australia
| | - F R Walker
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW, Australia
| | - M W Hale
- School of Psychological Science, La Trobe University, Melbourne, VIC, Australia
| | - S Kent
- School of Psychological Science, La Trobe University, Melbourne, VIC, Australia.
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MacDonald L, Hazi A, Paolini AG, Kent S. Calorie restriction dose-dependently abates lipopolysaccharide-induced fever, sickness behavior, and circulating interleukin-6 while increasing corticosterone. Brain Behav Immun 2014; 40:18-26. [PMID: 24440143 DOI: 10.1016/j.bbi.2014.01.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 12/15/2013] [Accepted: 01/08/2014] [Indexed: 01/08/2023] Open
Abstract
In mice a 50% calorie restriction (CR) for 28days attenuates sickness behavior after lipopolysaccharide (LPS) and these mice demonstrate a central anti-inflammatory bias. This study examined the dose-dependent effect of CR on sickness behavior (fever, anorexia, cachexia) and peripheral immune markers post-LPS. Male Sprague-Dawley rats fed ad libitum or CR by 50% for 14, 21, or 28days were injected on day 15, 22, or 29 with 50μg/kg of LPS or saline (1mL/500g). Changes in body temperature (Tb), locomotor activity, body weight, and food intake were determined. A separate cohort of rats was fed ad libitum or CR by 50% for 28days and serum levels of corticosterone (CORT), interleukin 6 (IL-6), and IL-10 were determined at 0, 2, and 4h post-LPS. The rats CR for 28days demonstrated the largest attenuation of sickness behavior: no fever, limited reduction in locomotor activity, no anorexia, and reduced cachexia following LPS. Rats CR for 14 and 21days demonstrated a partial attenuation of sickness behavior. Rats CR for 14days demonstrated a larger increase in Tb, larger reduction in locomotor activity, and larger weight loss compared to rats CR for 21days. Serum CORT was increased at 2h post-LPS in ad libitum and CR groups; however it was two times larger in the CR animals. Levels of IL-6 were significantly attenuated at 2h post-LPS in the CR animals. IL-10 levels were similar post-LPS. CR results in an enhanced anti-inflammatory response in the form of increased CORT and diminished pro-inflammatory signals.
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Affiliation(s)
- Leah MacDonald
- School of Psychological Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Agnes Hazi
- School of Psychological Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Antonio G Paolini
- School of Psychological Science, La Trobe University, Melbourne, VIC 3086, Australia
| | - Stephen Kent
- School of Psychological Science, La Trobe University, Melbourne, VIC 3086, Australia.
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13
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Radler ME, Hale MW, Kent S. Calorie restriction attenuates lipopolysaccharide (LPS)-induced microglial activation in discrete regions of the hypothalamus and the subfornical organ. Brain Behav Immun 2014; 38:13-24. [PMID: 24291211 DOI: 10.1016/j.bbi.2013.11.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/06/2013] [Accepted: 11/20/2013] [Indexed: 12/11/2022] Open
Abstract
Calorie restriction (CR) has been shown to increase longevity and elicit many health promoting benefits including delaying immunosenescence and attenuating neurodegeneration in animal models of Alzheimer's disease and Parkinson's disease. CR also suppresses microglial activation following cortical injury and aging. We previously demonstrated that CR attenuates lipopolysaccharide (LPS)-induced fever and shifts hypothalamic signaling pathways to an anti-inflammatory bias; however, the effects of CR on LPS-induced microglial activation remain largely unexplored. The current study investigated regional changes in LPS-induced microglial activation in mice exposed to 50% CR for 28days. Immunohistochemistry was conducted to examine changes in ionized calcium-binding adapter molecule-1 (Iba1), a protein constitutively expressed by microglia, in a total of 27 brain regions involved in immunity, stress, and/or thermoregulation. Exposure to CR attenuated LPS-induced fever, and LPS-induced microglial activation in a subset of regions: the arcuate nucleus (ARC) and ventromedial nucleus of the hypothalamus (VMH) and the subfornical organ (SFO). Microglial activation in the ARC and VMH was positively correlated with body temperature. These data suggest that CR exerts effects on regionally specific populations of microglia; particularly, in appetite-sensing regions of the hypothalamus, and/or regions lacking a complete blood brain barrier, possibly through altered pro- and anti-inflammatory signaling in these regions.
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Affiliation(s)
- Morgan E Radler
- School of Psychological Science, La Trobe University, Melbourne, VIC, Australia
| | - Matthew W Hale
- School of Psychological Science, La Trobe University, Melbourne, VIC, Australia
| | - Stephen Kent
- School of Psychological Science, La Trobe University, Melbourne, VIC, Australia.
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14
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Augustyniak D, Nowak J, Lundy FT. Direct and indirect antimicrobial activities of neuropeptides and their therapeutic potential. Curr Protein Pept Sci 2013; 13:723-38. [PMID: 23305360 PMCID: PMC3601409 DOI: 10.2174/138920312804871139] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 07/07/2012] [Accepted: 09/15/2012] [Indexed: 02/07/2023]
Abstract
As global resistance to conventional antibiotics rises we need to develop new strategies to develop future novel therapeutics. In our quest to design novel anti-infectives and antimicrobials it is of interest to investigate host-pathogen interactions and learn from the complexity of host defense strategies that have evolved over millennia. A myriad of host defense molecules are now known to play a role in protection against human infection. However, the interaction between host and pathogen is recognized to be a multifaceted one, involving countless host proteins, including several families of peptides. The regulation of infection and inflammation by multiple peptide families may represent an evolutionary failsafe in terms of functional degeneracy and emphasizes the significance of host defense in survival. One such family is the neuropeptides (NPs), which are conventionally defined as peptide neurotransmitters but have recently been shown to be pleiotropic molecules that are integral components of the nervous and immune systems. In this review we address the antimicrobial and anti-infective effects of NPs both in vitro and in vivo and discuss their potential therapeutic usefulness in overcoming infectious diseases. With improved understanding of the efficacy of NPs, these molecules could become an important part of our arsenal of weapons in the treatment of infection and inflammation. It is envisaged that targeted therapy approaches that selectively exploit the anti-infective, antimicrobial and immunomodulatory properties of NPs could become useful adjuncts to our current therapeutic modalities.
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Affiliation(s)
- Daria Augustyniak
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland.
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15
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Prolonged postsurgical recovery period and adverse effects of a leptin application in endotoxemic obese rodents. Life Sci 2013; 93:247-56. [DOI: 10.1016/j.lfs.2013.06.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 05/29/2013] [Accepted: 06/13/2013] [Indexed: 01/10/2023]
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16
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Mpouzika MDA, Papathanassoglou EDE, Giannakopoulou M, Bozas E, Middleton N, Boti S, Patiraki EI, Karabinis A. Altered serum stress neuropeptide levels in critically ill individuals and associations with lymphocyte populations. Neuropeptides 2013; 47:25-36. [PMID: 22981820 DOI: 10.1016/j.npep.2012.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 07/06/2012] [Accepted: 07/19/2012] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Potential physiological correlates of stress and the role of stress neuropeptides, other than those of the hypothalamic-pituitary-adrenal axis, in critical illness have not been addressed. We investigated: (a) serum levels of stress neuropeptides (ACTH, substance P (SP), neuropeptide Y (NPY), cortisol, prolactin) in critically ill individuals compared to matched controls, (b) associations with lymphocyte counts, (c) associations among stress neuropeptide levels, and (d) associations with perceived intensity of stress, critical illness severity and survival. METHODS Correlational design with repeated measures. Thirty-six critically ill patients were followed up for 14 days compared to 36 healthy matched controls. Stress was assessed by the ICUESS scale. Correlations, cross-sectional comparisons and multiple regression models were pursued. RESULTS For the first time, we report lower SP (Difference of means (DM) = 2928-3286 ng/ml, p < 0.001) and NPY (DM = 0.77-0.83 ng/ml, p < 0.0001) levels in critically ill individuals compared to controls. Cortisol levels were higher (DM = 140-173 ng/ml, p<0.0001) and lymphocyte population counts (p < 0.002) were lower in patients throughout the study. NPY levels associated with lymphocyte (r = 0.411-0.664, p < 0.04), T-lymphocyte (r = 0.403-0.781, p< 0.05), T-helper (r = 0.492-0.690, p < 0.03) and T-cytotoxic cell populations (r = 0.39-0.740, p < 0.03). On day 1, cortisol levels exhibited associations with lymphocyte (r = -0.452, p = 0.01), T-cell (r = -0.446, p = 0.02), T-helper (r = -0.428, p = 0.026) and T-cytotoxic cells ( r = -0.426, p = 0.027). ACTH levels associated with NK cell counts (r = 0.326-0.441, p < 0.05). Associations among stress neuropeptides levels were observed throughout (p < 0.05). ACTH levels associated with disease severity (r = 0.340-0.387, p < 0.005). A trend for an association between ACTH levels and intensity of stress was noted (r = 0.340, p = 0.057). CONCLUSION The significantly lowered NPY and SP levels and the associations with cortisol, ACTH and lymphocytes suggest that the role of these peptides in critical illness merit further investigation. Future studies need to address associations between these neuropeptides and functional immune cell responses and inflammatory markers in critical illness.
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Affiliation(s)
- Meropi D A Mpouzika
- Department of Nursing B, Faculty of Health and Caring Professions, Technological Educational Institute of Athens, Greece.
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17
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Benz-Woerner J, Delodder F, Benz R, Cueni-Villoz N, Feihl F, Rossetti AO, Liaudet L, Oddo M. Body temperature regulation and outcome after cardiac arrest and therapeutic hypothermia. Resuscitation 2012; 83:338-42. [PMID: 22079947 DOI: 10.1016/j.resuscitation.2011.10.026] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 10/21/2011] [Accepted: 10/30/2011] [Indexed: 10/15/2022]
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18
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Stadler J, Le TP, Haas P, Nave H. Distinct effects of NPY13-36, a specific NPY Y2 agonist, in a model of rodent endotoxemia on leukocyte subsets and cytokine levels. Ann Anat 2011; 193:486-93. [PMID: 22074679 DOI: 10.1016/j.aanat.2011.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 10/09/2011] [Accepted: 10/10/2011] [Indexed: 11/30/2022]
Abstract
Even now, sepsis remains a major problem in modern clinical medicine, leading to systemic inflammatory response including altered leukocyte subset distribution and increased cytokine release. As immune cells are known to express NPY receptors, we investigated the effects of a specific NPY Y(2) receptor agonist (NPY(13-36)) and/or the corresponding Y(2) receptor antagonist BIIE0246 treatment on blood (by FACS analyses) and tissue (by immunohistochemistry) leukocyte subsets as well as on levels of IL-4, IL-6, IL-10, TNF-α, INF-γ (by Cytometric Bead Array) in healthy and acutely endotoxemic rats. Results show a significant decrease in blood monocytes after LPS challenge in endotoxemic control animals (by 93%), in endotoxemic NPY(13-36) treated animals (by 83%) and in endotoxemic BIIE0246 treated animals (by 88%) as compared to the corresponding healthy controls. Endotoxemic control animals showed a significant increase of TNF-α (by 98%) as compared to the healthy control group. A treatment with NPY(13-36) significantly stabilized TNF-α level in endotoxemic animals. This study indicates distinct subset- and cytokine-specific in vivo effects induced by an NPY Y(2) receptor specific treatment after a short-term LPS challenge.
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Affiliation(s)
- Jan Stadler
- Institute for Functional and Applied Anatomy, Hannover Medical School, Germany
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19
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MacDonald L, Radler M, Paolini AG, Kent S. Calorie restriction attenuates LPS-induced sickness behavior and shifts hypothalamic signaling pathways to an anti-inflammatory bias. Am J Physiol Regul Integr Comp Physiol 2011; 301:R172-84. [PMID: 21525175 DOI: 10.1152/ajpregu.00057.2011] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Calorie restriction (CR) has been demonstrated to alter cytokine levels; however, its potential to modify sickness behavior (fever, anorexia, cachexia) has not. The effect of CR on sickness behavior was examined in male C57BL/6J mice fed ad libitum or restricted 25% (CR25%) or restricted 50% (CR50%) in food intake for 28 days and injected with 50 μg/kg of LPS on day 29. Changes in body temperature, locomotor activity, body weight, and food intake were determined. A separate cohort of mice were fed ad libitum or CR50% for 28 days, and hypothalamic mRNA expression of inhibitory factor κB-α (IκB-α), cyclooxygenase-2 (COX-2), prostaglandin E(2) (PGE(2)), suppressor of cytokine signaling 3 (SOCS3), IL-10, neuropeptide Y (NPY), leptin, proopiomelanocortin (POMC), and corticotrophin-releasing hormone (CRH) were determined at 0, 2, and 4 h post-LPS. CR50% mice did not develop fevers, whereas the CR25% mice displayed a fever shorter in duration but with the same peak as the controls. Both CR25% and CR50% mice showed no sign of anorexia and reduced cachexia after LPS administration. Hypothalamic mRNA expression of NPY and CRH were both increased by severalfold in CR50% animals preinjection compared with controls. The CR50% mice did not demonstrate the expected rise in hypothalamic mRNA expression of COX-2, microsomal prostaglandin E synthase-1, POMC, or CRH 2 h post-LPS, and leptin expression was decreased at this time point. Increases in SOCS3, IL-10, and IκB-α expression in CR50% animals were enhanced compared with ad libitum-fed controls at 4 h post-LPS. CR results in a suppression of sickness behavior in a dose-dependent manner, which may be due to CR attenuating proinflammatory pathways and enhancing anti-inflammatory pathways.
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Affiliation(s)
- Leah MacDonald
- School of Psychological Science, La Trobe University, Bundoora, VIC 3086, Australia
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20
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GLP-1 signaling preserves cardiac function in endotoxemic Fischer 344 and DPP4-deficient rats. Naunyn Schmiedebergs Arch Pharmacol 2010; 382:463-74. [DOI: 10.1007/s00210-010-0559-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 08/31/2010] [Indexed: 10/19/2022]
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21
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Hollis JH, Lemus M, Evetts MJ, Oldfield BJ. Central interleukin-10 attenuates lipopolysaccharide-induced changes in food intake, energy expenditure and hypothalamic Fos expression. Neuropharmacology 2009; 58:730-8. [PMID: 20045008 DOI: 10.1016/j.neuropharm.2009.12.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 12/13/2009] [Accepted: 12/18/2009] [Indexed: 10/20/2022]
Abstract
Lipopolysaccharide (LPS) is often used to mimic acute infection and induces hypophagia, the selective partitioning of fat for energy, and fever. Interleukin-10 (IL-10) is an anti-inflammatory cytokine expressed in the brain which attenuates LPS-induced hypophagia; however the potential sites of interaction within the brain have not been investigated. Hypothalamic orexin (ORX) and melanin-concentrating hormone (MCH) regulate energy expenditure and food intake although the regulation of these neuropeptides through the interactions between central IL-10 and the inflammatory consequences of peripheral LPS have not been investigated. The present study in the rat investigated during the dark phase of the light-dark cycle the ability of central IL-10 (250 ng, i.c.v.) to attenuate the changes in food intake, energy substrate partitioning, and central Fos expression within the hypothalamus to peripheral LPS (100 microg/kg, i.p.); Fos expression changes specifically within ORX and MCH neurons were also investigated. Central IL-10 attenuated the peripheral LPS-induced hypophagia, reduction in motor activity, fever and reduction in respiratory exchange ratio. Central IL-10 also attenuated peripheral LPS-induced increases in Fos expression within ORX neurons and decreases in Fos expression within unidentified cells of the caudal arcuate nucleus. In contrast, both IL-10 and LPS injection independently decreased Fos expression within MCH neurons. The present study provides further insight into the interactions within the brain between the anti-inflammatory cytokine IL-10, the inflammatory consequences of LPS, and neuropeptides known to regulate energy expenditure and food intake.
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Affiliation(s)
- Jacob H Hollis
- Department of Physiology, Monash University, Victoria, Australia.
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22
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Hofbauer KG, Lecourt AC, Peter JC. Antibodies as pharmacologic tools for studies on the regulation of energy balance. Nutrition 2008; 24:791-7. [PMID: 18662861 DOI: 10.1016/j.nut.2008.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 06/03/2008] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Active immunization in rats may serve several purposes: the production of a disease-like phenotype, the generation of pharmacologic tools, and the development of clinically useful therapies. We selected the melanocortin-4 receptor (MC4R) as a target because its blockade could provide a treatment for anorexia and cachexia. METHODS We used a sequence of the N-terminal (NT) domain of the MC4R as an antigen. Rats immunized against the NT peptide produced specific MC4R antibodies (Abs) that were purified and characterized in vitro and in vivo. RESULTS The Abs acted as inverse agonists and reduced under basal conditions the production of cyclic adenosine monophosphate in HEK-293 cells expressing the human MC4R. Rats immunized against the NT peptide developed a phenotype consistent with hypothalamic MC4R blockade, i.e., increased food intake and body weight, liver and fat-pad weights, hepatic steatosis, and increased plasma triacylglycerols. With a high-fat diet, plasma insulin levels were significantly increased. In separate experiments an increase in food intake was observed after injection of purified MC4R Abs into the third ventricle. When lipopolysaccharide was administered in NT-immunized rats the reduction of food intake was partly prevented in this model of cytokine-induced anorexia. CONCLUSION Our results show that active immunization of rats against the MC4R resulted in the generation of specific Abs that stimulated food intake by acting as inverse agonists of the hypothalamic MC4R. Pharmacologically active monoclonal MC4R Abs could be the starting point for the development of novel treatments for patients with anorexia or cachexia.
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Affiliation(s)
- Karl G Hofbauer
- Applied Pharmacology, Biozentrum, University of Basel, Basel, Switzerland.
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23
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Painsipp E, Herzog H, Holzer P. Implication of neuropeptide-Y Y2 receptors in the effects of immune stress on emotional, locomotor and social behavior of mice. Neuropharmacology 2008; 55:117-26. [PMID: 18508096 DOI: 10.1016/j.neuropharm.2008.05.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 04/22/2008] [Accepted: 05/06/2008] [Indexed: 01/09/2023]
Abstract
Neuropeptide Y (NPY) is involved in the regulation of emotional behavior, and there is indirect evidence for a role of NPY in the cerebral responses to peripheral immune challenge. Since the NPY receptors involved in these reactions are not known, we investigated the effect of Escherichia coli lipopolysaccharide (LPS) on emotional, locomotor and social behavior, body temperature and circulating corticosterone in female Y2 (Y2-/-) and Y4 (Y4-/-) receptor knockout mice. LPS (0.1mg/kg injected IP 2.5h before testing) increased rectal temperature in control and Y4-/- mice to a larger degree than in Y2-/- animals. Both Y2-/- and Y4-/- mice exhibited reduced anxiety-related and depression-like behavior in the open field, elevated plus-maze and tail suspension test, respectively. While depression-like behavior was not changed by LPS, anxiety-related behavior was enhanced by LPS in Y2-/-, but not control and Y4-/- animals. Y2-/- mice were also particularly susceptible to the effect of LPS to attenuate locomotor behavior and social interaction with another mouse. The corticosterone response to LPS was blunted in Y2-/- mice which presented elevated levels of circulating corticosterone following vehicle treatment. These data show that Y2-/- mice are particularly sensitive to the effects of LPS-evoked immune stress to attenuate locomotion and social interaction and to increase anxiety-like behavior, while the LPS-induced rise of temperature and circulating corticosterone is suppressed by Y2 receptor knockout. Our observations attest to an important role of endogenous NPY acting via Y2 receptors in the cerebral response to peripheral immune challenge.
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MESH Headings
- Analysis of Variance
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Corticosterone/blood
- Exploratory Behavior/drug effects
- Exploratory Behavior/physiology
- Female
- Fever/etiology
- Immobility Response, Tonic/drug effects
- Immobility Response, Tonic/physiology
- Lipopolysaccharides/pharmacology
- Locomotion/physiology
- Maze Learning/drug effects
- Mice
- Mice, Knockout
- Receptors, Neuropeptide Y/deficiency
- Receptors, Neuropeptide Y/physiology
- Social Behavior
- Stress, Psychological/blood
- Stress, Psychological/chemically induced
- Stress, Psychological/physiopathology
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Affiliation(s)
- Evelin Painsipp
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Universitätsplatz 4, A-8010 Graz, Austria
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24
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Sajdyk TJ, Johnson PL, Leitermann RJ, Fitz SD, Dietrich A, Morin M, Gehlert DR, Urban JH, Shekhar A. Neuropeptide Y in the amygdala induces long-term resilience to stress-induced reductions in social responses but not hypothalamic-adrenal-pituitary axis activity or hyperthermia. J Neurosci 2008; 28:893-903. [PMID: 18216197 PMCID: PMC6671007 DOI: 10.1523/jneurosci.0659-07.2008] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 12/06/2007] [Accepted: 12/07/2007] [Indexed: 12/16/2022] Open
Abstract
Resilience to mental and physical stress is a key determinant for the survival and functioning of mammals. Although the importance of stress resilience has been recognized, the underlying neural mediators have not yet been identified. Neuropeptide Y (NPY) is a peptide known for its anti-anxiety-like effects mediated via the amygdala. The results of our current study demonstrate, for the first time that repeated administration of NPY directly into the basolateral nucleus of the amygdala (BLA) produces selective stress-resilient behavioral responses to an acute restraint challenge as measured in the social interaction test, but has no effect on hypothalamic-adrenal-pituitary axis activity or stress-induced hyperthermia. More importantly, the resilient behaviors observed in the NPY-treated animals were present for up to 8 weeks. Antagonizing the activity of calcineurin, a protein phosphatase involved in neuronal remodeling and present in NPY receptor containing neurons within the BLA, blocked the development of long-term, but not the acute increases in social interaction responses induced by NPY administration. This suggests that the NPY-induced long-term behavioral resilience to restraint stress may occur via mechanisms involving neuronal plasticity. These studies suggest one putative physiologic mechanism underlying stress resilience and could identify novel targets for development of therapies that can augment the ability to cope with stress.
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Affiliation(s)
- Tammy J Sajdyk
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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25
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Prenzler NK, Macke C, Horn R, Brabant G, Pabst R, Richter M, Nave H. Obesity influences the food consumption and cytokine pattern in ghrelin-treated endotoxemic rats. Life Sci 2007; 81:80-7. [PMID: 17532346 DOI: 10.1016/j.lfs.2007.04.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Revised: 04/18/2007] [Accepted: 04/23/2007] [Indexed: 12/27/2022]
Abstract
Obese patients have an increased incidence of systemic infections and higher morbidity and mortality rates than normal weight subjects. Ghrelin is a potent orexigenic signal from the stomach and seems to play a role in the generation and control of immune interactions. To examine a possible benefit of a single ghrelin application on acute endotoxemia, chronic intravenous (i.v.) cannulated lean and diet-induced obese male LEW rats were treated with a bolus injection of either ghrelin (10 nmol/kg) or vehicle, 10 min prior to a challenge with a sublethal bolus of endotoxin (100 microg/kg) or vehicle. Multiple blood samples were taken within a period from 24 h before the experiment up to 24 h after the endotoxin challenge to measure ghrelin and cytokine levels. Additionally, food consumption was recorded and ghrelin expression in fore- and glandular stomach was evaluated immunohistochemically. Despite higher serum ghrelin levels, the food consumption was significantly decreased in obese endotoxemic rats compared to lean littermates after ghrelin treatment. Furthermore we could show an increase of anti-inflammatory IL-10 serum levels after ghrelin treatment of normal weight endotoxemic and an opposite effect in obese animals. As the therapy of disease-associated cachexia and various immunological problems in endotoxemia is still insufficient, peptides such as ghrelin with their modulating abilities for the endocrine and the immune system are of special interest. However, the present study shows that the beneficial effects of ghrelin were attenuated in obese endotoxemic animals. These data further document the necessity to differentiate between normal weight and obese subjects in the attempt to establish ghrelin as a therapeutic target in endotoxemia.
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Affiliation(s)
- Nils K Prenzler
- Department of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str.1, 30625 Hannover, Germany
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Akarsu ES, Mamuk S. Escherichia coli lipopolysaccharides produce serotype-specific hypothermic response in biotelemetered rats. Am J Physiol Regul Integr Comp Physiol 2007; 292:R1846-50. [PMID: 17272660 DOI: 10.1152/ajpregu.00786.2006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated whether LPS-induced hypothermia develops in a serotype-specific manner in biotelemetered conscious rats. Two different Escherichia coli serotypes of LPSs were injected at a dose of 250 mug/kg ip. E. coli O55:B5 LPS elicited an initial hypothermia and subsequent fever, but E. coli O111:B4 LPS caused more potent monophasic hypothermia. Serum tumor necrosis factor (TNF)-alpha levels were dramatically elevated at the initial phase of the hypothermia induced by both LPSs. This elevation tended to subside at the nadir of E. coli O55:B5 LPS-induced response but progressively increased at the nadir of E. coli O111:B4 LPS hypothermia. Serum IL-10 levels were moderately elevated at the initial phase of the hypothermia and persisted at the same level at the nadir of each LPS-induced response. No change was observed at the serum IL-18 levels. A selective cyclooxygenase (COX)-1 enzyme inhibitor, valeryl salicylate (20 mg/kg sc), abolished the hypothermia without any effect on the elevated cytokine levels. Another COX-1-selective inhibitor, 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole (SC-560; 1 mg/kg sc) inhibited hypothermic responses as well. Meanwhile, cytokine levels were also reduced by SC-560 treatment. These findings suggest that LPS-induced hypothermia may have serotype-specific characteristics in rats. E. coli O111:B4 LPS has more potent hypothermic activity than E. coli O55:B5 LPS; that may presumably be related to its higher or sustained capability to release antipyretic cytokines, such as TNF-alpha. COX-1 enzyme may be involved in the generation of the hypothermia, regardless of the type of LPS administered.
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Affiliation(s)
- Eyup S Akarsu
- Ankara Univ, School of Medicine, Dept of Pharmacology and Clinical Pharmacology, Sihhiye, Ankara, Turkey.
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Piao H, Nagai S, Tsurumaki T, Niki T, Higuchi H. Potentiation by neuropeptide Y of histamine H1 receptor-mediated contraction in rat blood vessels. Vascul Pharmacol 2006; 46:260-70. [PMID: 17169617 DOI: 10.1016/j.vph.2006.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 10/01/2006] [Accepted: 10/19/2006] [Indexed: 11/20/2022]
Abstract
Histamine-induced contraction and its potentiation by neuropeptide Y were investigated in rat blood vessels. Rat arteries and veins constricted with single concentrations of histamine dose-dependently (0.1-100 microM). This histamine-induced contraction immediately desensitized. Histamine H1 receptor antagonists, 1 microM mepyramine and 1 microM diphenhydramine, abolished this transient contraction completely, whereas cimetidine, phentolamine, reserpine and tetrodotoxin failed to inhibit the contraction. Histamine H1 receptor mRNA level by reverse transcription-polymerase chain reaction was quite parallel to histamine H1 receptor-mediated contraction, indicating that the contraction is mediated through histamine H1 receptors in the smooth muscle. Neuropeptide Y (10 nM in arteries and 3 nM in veins, respectively) significantly potentiated histamine H1 receptor-mediated contraction via neuropeptide Y1 receptors in most of rat blood vessels. Since the phospholipase C inhibitors, neomycin (1 mM) and 2-nitro-4-carboxyphenyl-N, N-diphenylcarbamate (NCDC, 10 microM), respectively, specifically abolished the potentiation, the potentiation by neuropeptide Y may depend on activation of phospholipase C.
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Affiliation(s)
- Honglan Piao
- Division of Pharmacology, Department of Molecular genetics and Signal Transduction Research, Course for Molecular and Cellular Medicine, Niigata University Graduate School of Medical and Dental Sciences, Japan
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Karrow NA. Activation of the hypothalamic-pituitary-adrenal axis and autonomic nervous system during inflammation and altered programming of the neuroendocrine-immune axis during fetal and neonatal development: lessons learned from the model inflammagen, lipopolysaccharide. Brain Behav Immun 2006; 20:144-58. [PMID: 16023324 DOI: 10.1016/j.bbi.2005.05.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 05/09/2005] [Accepted: 05/12/2005] [Indexed: 10/25/2022] Open
Abstract
The hypothalamic-pituitary-adrenal axis (HPAA) and autonomic nervous system (ANS) are both activated during inflammation as an elaborate multi-directional communication pathway designed to restore homeostasis, in part, by regulating the inflammatory and subsequent immune response. During fetal and neonatal development programming of the HPAA, ANS and possibly the immune system is influenced by signals from the surrounding environment, as part of an adaptive mechanism to enhance the survival of the offspring. It is currently hypothesized that if this programming is either misguided, or the individual's environment is drastically altered such that neuroendocrine programming becomes maladaptive, it may contribute to the pathogenesis of certain diseases. Current research, suggests that exposure to inflammatory signals during critical windows of early life development may influence the programming of various genes within the neuroendocrine-immune axis. This review will provide, (1) an overview of the HPAA and ANS pathways that are activated during inflammation, highlighting studies that have used lipopolysaccharide as a model inflammagen and, (2) evidence to support the hypothesis that inflammatory stress during fetal and neonatal development can alter programming of the neuroendocrine-immune axis, influencing stress and immune responsiveness, and possibly disease resistance later in life.
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Affiliation(s)
- N A Karrow
- Centre for the Genetic Improvement of Livestock, Department of Animal and Poultry Science, University of Guelph, Ont., Canada, N1G 2W1.
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Felies M, Poppendieck S, Nave H. Perioperative normothermia depends on intraoperative warming procedure, extent of the surgical intervention and age of the experimental animal. Life Sci 2005; 77:3133-40. [PMID: 15979105 DOI: 10.1016/j.lfs.2005.03.032] [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: 02/04/2005] [Accepted: 03/22/2005] [Indexed: 11/20/2022]
Abstract
The maintenance of a physiological body temperature during and early after surgical interventions in experimental animals such as rodents is often neglected. Therefore the positive influence of an adequate use of warming blankets (WB) on the rectal body temperature in rats was investigated during two different surgical interventions, with a special focus on possible differences between young adult (2.5+/-0.14 months) and adult animals (9.3+/-0.13 months). Anesthesia was induced with isoflurane short inhalation and maintained with ketamine and domitor intramuscularly. Animals were divided into ten groups according to (a) the age of the animals, (b) the temperature of the WB and (c) the kind of surgical intervention (either an intravenous [i.v.] cannulation of the right external jugular vein or an intra-aortal implantation of a telemetric transmitter or both). Results clearly show that the surface temperature of the WB has a major impact on the perioperative thermoregulation. The rectal body temperature of animals operated on a cooler WB dramatically decreased depending on the age of the rat and also on the extent of the surgical intervention. The opening of the abdominal cavity in older rats resulted in a severe hypothermia: they lost 5.6 degrees C compared to 3.2 degrees C in the young adult rats. The implantation of the i.v. catheter had no serious effect on the thermoregulation. In conclusion, the results clearly show that an adequate perioperative warming system positively influences the postoperative outcome in young adult and most notably in adult rats and thus enables early postoperative experiments without effects on measured parameters.
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Affiliation(s)
- Melanie Felies
- Department of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str.1, 30625 Hannover, Germany
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