1
|
Saramago EA, Borges GS, Singolani-Jr CG, Nogueira JE, Soriano RN, Cárnio EC, Branco LGS. Molecular hydrogen potentiates hypothermia and prevents hypotension and fever in LPS-induced systemic inflammation. Brain Behav Immun 2019; 75:119-128. [PMID: 30261305 DOI: 10.1016/j.bbi.2018.09.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/21/2018] [Accepted: 09/24/2018] [Indexed: 10/28/2022] Open
Abstract
Molecular hydrogen (H2) exerts anti-oxidative, anti-apoptotic, and anti-inflammatory effects. Here we tested the hypothesis that H2 modulates cardiovascular, inflammatory, and thermoregulatory changes in systemic inflammation (SI) induced by lipopolysaccharide (LPS) at different doses (0.1 or 1.5 mg/kg, intravenously, to induce mild or severe SI) in male Wistar rats (250-300 g). LPS or saline was injected immediately before the beginning of 360-minute inhalation of H2 (2% H2, 21% O2, balanced with nitrogen) or room air (21% O2, balanced with nitrogen). Deep body temperature (Tb) was measured by dataloggers pre-implanted in the peritoneal cavity. H2 caused no change in cardiovascular, inflammatory parameters, and Tb of control rats (treated with saline). During mild SI, H2 reduced plasma surges of proinflammatory cytokines (TNF-α and IL-6) while caused an increase in plasma IL-10 (anti-inflammatory cytokine) and prevented fever. During severe SI, H2 potentiated hypothermia, and prevented fever and hypotension, which coincided with reduced plasma nitric oxide (NO) production. Moreover, H2 caused a reduction in surges of proinflammatory cytokines (plasma TNF-α and IL-1β) and prostaglandin E2 [(PGE2), in plasma and hypothalamus], and an increase in plasma IL-10. These data are consistent with the notion that H2 blunts fever in mild SI, and during severe SI potentiates hypothermia, prevents hypotension reducing plasma NO production, and exerts anti-inflammatory effects strong enough to prevent fever by altering febrigenic signaling and ultimately down-modulating hypothalamic PGE2 production.
Collapse
Affiliation(s)
- Eduardo A Saramago
- Medical School of Ribeirão Preto, 14049-900, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Gabriela S Borges
- Medical School of Ribeirão Preto, 14049-900, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Carlitos G Singolani-Jr
- Medical School of Ribeirão Preto, 14049-900, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jonatas E Nogueira
- Medical School of Ribeirão Preto, 14049-900, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; School of Physical Education and Sports of Ribeirao Preto, 14030-680, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Renato N Soriano
- Division of Physiology and Biophysics, Department of Basic Life Sciences, 35010-177, Federal University of Juiz de Fora, Governador Valadares, Minas Gerais, Brazil
| | - Evelin C Cárnio
- Nursing School of Ribeirão Preto, 14040-902, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luiz G S Branco
- Dental School of Ribeirão Preto, 14040-904, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| |
Collapse
|
2
|
Neural pathways involved in infection-induced inflammation: recent insights and clinical implications. Clin Auton Res 2018. [PMID: 29541878 DOI: 10.1007/s10286-018-0518-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Although the immune and nervous systems have long been considered independent biological systems, they turn out to mingle and interact extensively. The present review summarizes recent insights into the neural pathways activated by and involved in infection-induced inflammation and discusses potential clinical applications. The simplest activation concerns a reflex action within C-fibers leading to neurogenic inflammation. Low concentrations of pro-inflammatory cytokines or bacterial fragments may also act on these afferent nerve fibers to signal the central nervous system and bring about early fever, hyperalgesia and sickness behavior. In the brain, the preoptic area and the paraventricular hypothalamus are part of a neuronal network mediating sympathetic activation underlying fever while brainstem circuits play a role in the reduction of food intake after systemic exposure to bacterial fragments. A vagally-mediated anti-inflammatory reflex mechanism has been proposed and, in turn, questioned because the major immune organs driving inflammation, such as the spleen, are not innervated by vagal efferent fibers. On the contrary, sympathetic nerves do innervate these organs and modulate immune cell responses, production of inflammatory mediators and bacterial dissemination. Noradrenaline, which is both released by these fibers and often administered during sepsis, along with adrenaline, may exert pro-inflammatory actions through the stimulation of β1 adrenergic receptors, as antagonists of this receptor have been shown to exert anti-inflammatory effects in experimental sepsis.
Collapse
|
3
|
Steiner AA, Flatow EA, Brito CF, Fonseca MT, Komegae EN. Respiratory gas exchange as a new aid to monitor acidosis in endotoxemic rats: relationship to metabolic fuel substrates and thermometabolic responses. Physiol Rep 2017; 5:5/1/e13100. [PMID: 28082427 PMCID: PMC5256159 DOI: 10.14814/phy2.13100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/01/2016] [Accepted: 12/03/2016] [Indexed: 11/26/2022] Open
Abstract
This study introduces the respiratory exchange ratio (RER; the ratio of whole‐body CO2 production to O2 consumption) as an aid to monitor metabolic acidosis during the early phase of endotoxic shock in unanesthetized, freely moving rats. Two serotypes of lipopolysaccharide (lipopolysaccharide [LPS] O55:B5 and O127:B8) were tested at shock‐inducing doses (0.5–2 mg/kg). Phasic rises in RER were observed consistently across LPS serotypes and doses. The RER rise often exceeded the ceiling of the quotient for oxidative metabolism, and was mirrored by depletion of arterial bicarbonate and decreases in pH. It occurred independently of ventilatory adjustments. These data indicate that the rise in RER results from a nonmetabolic CO2 load produced via an acid‐induced equilibrium shift in the bicarbonate buffer. Having validated this new experimental aid, we asked whether acidosis was interconnected with the metabolic and thermal responses that accompany endotoxic shock in unanesthetized rats. Contrary to this hypothesis, however, acidosis persisted regardless of whether the ambient temperature favored or prevented downregulation of mitochondrial oxidation and regulated hypothermia. We then asked whether the substrate that fuels aerobic metabolism could be a relevant factor in LPS‐induced acidosis. Food deprivation was employed to divert metabolism away from glucose oxidation and toward fatty acid oxidation. Interestingly, this intervention attenuated the RER response to LPS by 58%, without suppressing other key aspects of systemic inflammation. We conclude that acid production in unanesthetized rats with endotoxic shock results from a phasic activation of glycolysis, which occurs independently of physiological changes in mitochondrial oxidation and body temperature.
Collapse
Affiliation(s)
- Alexandre A Steiner
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elizabeth A Flatow
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Camila F Brito
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Monique T Fonseca
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Evilin N Komegae
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
4
|
Millington WR, Yilmaz MS, Feleder C. The initial fall in arterial pressure evoked by endotoxin is mediated by the ventrolateral periaqueductal gray. Clin Exp Pharmacol Physiol 2017; 43:612-5. [PMID: 27009880 DOI: 10.1111/1440-1681.12573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/04/2016] [Accepted: 03/21/2016] [Indexed: 11/29/2022]
Abstract
This study tested the hypothesis that the initial fall in arterial pressure evoked by lipopolysaccharide (LPS) is mediated by the ventrolateral column of the midbrain periaqueductal gray region (vlPAG). To test this hypothesis, the local anaesthetic lidocaine (2%; 0.1 μL, 0.2 μL or 1.0 μL), the delta opioid receptor antagonist naltrindole (2 nmol) or saline was microinjected into the vlPAG of isoflurane-anaesthetized rats bilaterally and LPS (1 mg/kg) or saline was administered intravenously 2 min later. Both lidocaine and naltrindole inhibited LPS-evoked hypotension significantly but did not affect arterial pressure in saline-treated control animals. Neither lidocaine nor naltrindole altered heart rate significantly in either LPS-treated or control animals. Microinjection of lidocaine or naltrindole into the dorsolateral PAG was ineffective. These data indicate that the vlPAG plays an important role in the initiation of endotoxic hypotension and further show that delta opioid receptors in the vlPAG participate in the response.
Collapse
Affiliation(s)
- William R Millington
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| | - M Sertac Yilmaz
- Department of Medical Pharmacology, Faculty of Medicine, Uludag University, Bursa, Turkey
| | - Carlos Feleder
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| |
Collapse
|
5
|
Surkin PN, Di Rosso ME, Correa F, Elverdin JC, Genaro AM, De Laurentiis A, Fernández-Solari J. Participation of hypothalamic CB1 receptors in reproductive axis disruption during immune challenge. J Neuroendocrinol 2017; 29. [PMID: 28665507 DOI: 10.1111/jne.12499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 06/26/2017] [Accepted: 06/26/2017] [Indexed: 12/24/2022]
Abstract
Immune challenge inhibits reproductive function and endocannabinoids (eCB) modulate sexual hormones. However, no studies have been performed to assess whether the eCB system mediates the inhibition of hormones that control reproduction as a result of immune system activation during systemic infections. For that reason, we evaluated the participation of the hypothalamic cannabinoid receptor CB1 on the hypothalamic-pituitary-gonadal (HPG) axis activity in rats submitted to immune challenge. Male adult rats were treated i.c.v. administration with a CB1 antagonist/inverse agonist (AM251) (500 ng/5 μL), followed by an i.p. injection of lipopolysaccharide (LPS) (5 mg/kg) 15 minutes later. Plasmatic, hypothalamic and adenohypophyseal pro-inflammatory cytokines, hormones and neuropeptides were assessed 90 or 180 minutes post-LPS. The plasma concentration of tumour necrosis factor α and adenohypophyseal mRNA expression of Tnfα and Il1β increased 90 and 180 minutes post i.p. administration of LPS. However, cytokine mRNA expression in the hypothalamus increased only 180 minutes post-LPS, suggesting an inflammatory delay in this organ. CB1 receptor blockade with AM251 increased LPS inflammatory effects, particularly in the hypothalamus. LPS also inhibited the HPG axis by decreasing gonadotrophin-releasing hormone hypothalamic content and plasma levels of luteinising hormone and testosterone. These disruptor effects were accompanied by decreased hypothalamic Kiss1 mRNA expression and prostaglandin E2 content, as well as by increased gonadotrophin-inhibitory hormone (Rfrp3) mRNA expression. All these disruptive effects were prevented by the presence of AM251. In summary, our results suggest that, in male rats, eCB mediate immune challenge-inhibitory effects on reproductive axis at least partially via hypothalamic CB1 activation. In addition, this receptor also participates in homeostasis recovery by modulating the inflammatory process taking place after LPS administration.
Collapse
Affiliation(s)
- P N Surkin
- Facultad de Odontología, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - M E Di Rosso
- Pontificia Universidad Católica Argentina (UCA), Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Biomédicas (BIOMED), Buenos Aires, Argentina
| | - F Correa
- Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - J C Elverdin
- Facultad de Odontología, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - A M Genaro
- Pontificia Universidad Católica Argentina (UCA), Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Biomédicas (BIOMED), Buenos Aires, Argentina
- Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - A De Laurentiis
- Facultad de Odontología, Universidad de Buenos Aires, Buenos Aires, Argentina
- Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - J Fernández-Solari
- Facultad de Odontología, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| |
Collapse
|
6
|
Göktalay G, Millington WR. Hypovolemic hemorrhage induces Fos expression in the rat hypothalamus: Evidence for involvement of the lateral hypothalamus in the decompensatory phase of hemorrhage. Neuroscience 2016; 322:464-78. [PMID: 26947128 DOI: 10.1016/j.neuroscience.2016.02.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 02/10/2016] [Accepted: 02/27/2016] [Indexed: 01/02/2023]
Abstract
This study tested the hypothesis that the hypothalamus participates in the decompensatory phase of hemorrhage by measuring Fos immunoreactivity and by inhibiting neuronal activity in selected hypothalamic nuclei with lidocaine or cobalt chloride. Previously, we reported that inactivation of the arcuate nucleus inhibited, but did not fully prevent, the fall in arterial pressure evoked by hypotensive hemorrhage. Here, we report that hemorrhage (2.2 ml/100g body weight over 20 min) induced Fos expression in a high percentage of cells in the paraventricular, supraoptic and arcuate nuclei of the hypothalamus as shown previously. Lower densities of Fos immunoreactive cells were also found in the medial preoptic area (mPOA), anterior hypothalamus, lateral hypothalamus (LH), dorsomedial hypothalamus, ventromedial hypothalamus (VMH) and posterior hypothalamus. Bilateral injection of lidocaine (2%; 0.1 μl or 0.3 μl) or cobalt chloride (5mM; 0.3 μl) into the tuberal portion of the LH immediately before hemorrhage was initiated reduced the magnitude of hemorrhagic hypotension and bradycardia significantly. Lidocaine injection into the VMH also attenuated the fall in arterial pressure and heart rate evoked by hemorrhage although inactivation of the mPOA or rostral LH was ineffective. These findings indicate that hemorrhage activates neurons throughout much of the hypothalamus and that a relatively broad area of the hypothalamus, extending from the arcuate nucleus laterally through the caudal VMH and tuberal LH, plays an important role in the decompensatory phase of hemorrhage.
Collapse
Affiliation(s)
- G Göktalay
- Department of Medical Pharmacology, Uludag University, Faculty of Medicine, Bursa, Turkey
| | - W R Millington
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY, United States.
| |
Collapse
|
7
|
Widening and Elaboration of Consecutive Research into Therapeutic Antioxidant Enzyme Derivatives. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3075695. [PMID: 27148430 PMCID: PMC4842371 DOI: 10.1155/2016/3075695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/16/2016] [Accepted: 03/16/2016] [Indexed: 01/03/2023]
Abstract
Undiminishing actuality of enzyme modification for therapeutic purposes has been confirmed by application of modified enzymes in clinical practice and numerous research data on them. Intravenous injection of the superoxide dismutase-chondroitin sulfate-catalase (SOD-CHS-CAT) conjugate in preventive and medicative regimes in rats with endotoxin shock induced with a lipopolysaccharide bolus has demonstrated that antioxidant agents not only effectively prevent damage caused by oxidative stress (as believed previously) but also can be used for antioxidative stress therapy. The results obtained emphasize the importance of investigation into the pathogenesis of vascular damage and the role of oxidative stress in it. The effects of intravenous medicative injection of SOD-CHS-CAT in a rat model of endotoxin shock have demonstrated a variety in the activity of this conjugate in addition to prevention of NO conversion in peroxynitrite upon interaction with O2∙− superoxide radical. Together with the literature data, these findings offer a prospect for the study of NO-independent therapeutic effects of SOD-CHS-CAT, implying the importance of a better insight into the mechanisms of the conjugate activity in modeled cardiovascular damage involving vasoactive agents other than NO.
Collapse
|
8
|
The intracerebroventricular injection of rimonabant inhibits systemic lipopolysaccharide-induced lung inflammation. J Neuroimmunol 2015; 286:16-24. [PMID: 26298320 DOI: 10.1016/j.jneuroim.2015.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 06/22/2015] [Accepted: 07/01/2015] [Indexed: 01/23/2023]
Abstract
We investigated the role of intracerebroventricular (ICV) injection of rimonabant (500ng), a CB1 antagonist, on lipopolysaccharide ((LPS) 5mg/kg)-induced pulmonary inflammation in rats in an isolated perfused lung model. There were decreases in pulmonary capillary pressure (Ppc) and increases in the ((Wet-Dry)/Dry lung weight)/(Ppc) ratio in the ICV-vehicle/LPS group at 4h. There were decreases in TLR4 pathway markers, such as interleukin receptor-associated kinase-1, IκBα, Raf1 and phospho-SFK (Tyr416) at 30min and at 4h increases in IL-6, vascular cell adhesion molecule-1 and myeloperoxidase in lung homogenate. Intracerebroventricular rimonabant attenuated these LPS-induced responses, indicating that ICV rimonabant modulates LPS-initiated pulmonary inflammation.
Collapse
|
9
|
Feleder C, Sertac Yilmaz M, Peng J, Göktalay G, Millington WR. The OVLT initiates the fall in arterial pressure evoked by high dose lipopolysaccharide: evidence that dichotomous, dose-related mechanisms mediate endotoxic hypotension. J Neuroimmunol 2015. [PMID: 26198924 DOI: 10.1016/j.jneuroim.2015.05.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study tested the hypothesis that lipopolysaccharide (LPS) lowers arterial pressure through two different mechanisms depending on the dose. Previously, we found that a low hypotensive dose of LPS (1mg/kg) lowers arterial pressure by activating vagus nerve afferents. Here we report that hypotension evoked by high dose LPS (15mg/kg) can be prevented by injecting lidocaine into the OVLT but not by vagotomy or inactivation of the NTS. The hypotension produced by both LPS doses was correlated with elevated extracellular norepinephrine concentrations in the POA and prevented by blocking alpha-adrenergic receptors. Thus, initiation of endotoxic hypotension is dose-related, mechanistically.
Collapse
Affiliation(s)
- Carlos Feleder
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, United States
| | - M Sertac Yilmaz
- Department of Medical Pharmacology, Uludag University, Faculty of Medicine, Bursa 16059, Turkey
| | - Jianya Peng
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, United States
| | - Gökhan Göktalay
- Department of Medical Pharmacology, Uludag University, Faculty of Medicine, Bursa 16059, Turkey
| | - William R Millington
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, United States.
| |
Collapse
|
10
|
Lv KY, Zhong QS, Liu XF, Zhu SH, Xiao SC, Wang GY, Ma B, Xia ZF. Deficiency of Smad3 results in enhanced inducible nitric oxide synthase-mediated hypotension in lipopolysaccharide-induced endotoxemia. J Surg Res 2013; 187:640-5. [PMID: 24332550 DOI: 10.1016/j.jss.2013.11.1090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/14/2013] [Accepted: 11/15/2013] [Indexed: 12/27/2022]
Abstract
BACKGROUND Smad3 is a principal intracellular mediator of signaling for transforming growth factor β, a cytokine involved in pleiotropic pathophysiological processes including inflammation and immunity. The function of Smad3 in regulating inducible nitric oxide synthase (iNOS) expression and septic shock has not been characterized. METHODS Smad3(-/-) (referred hereafter as KO) and wild-type (WT) mice were injected intraperitoneally with lipopolysaccharide (LPS) to induce the septic hypotension. Mortality, blood pressure, and plasma levels of nitrite were measured. The iNOS messenger RNA and protein levels in lung, kidney, and spleen were also analyzed. RESULTS Mice lacking functional Smad3 respond to LPS with greater mortality than their WT littermates. The high mortality of KO mice is accompanied by enhanced hypotension after intraperitoneal injection of LPS. Both KO and WT mice displayed an increase in plasma nitrite during the experimental period; however, LPS administration caused more dramatic changes in KO mice than WT mice. Likewise, the iNOS messenger RNA and protein levels in lung, kidney, and spleen were more strongly increased in KO mice than in WT mice after LPS administration. CONCLUSIONS Defects in the Smad3 gene may increase susceptibility to the development of septic hypotension because of enhanced iNOS production.
Collapse
Affiliation(s)
- Kai-Yang Lv
- Department of Burn & Burn Center, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Qi-Sheng Zhong
- Department of Neurosurgery, General Hospital of Jinan Military Command of Chinese PLA, Jinan, Shandong, China
| | - Xue-Feng Liu
- Department of Critical Care and Emergency Medicine, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Shi-Hui Zhu
- Department of Burn & Burn Center, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Shi-Chu Xiao
- Department of Burn & Burn Center, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Guang-Yi Wang
- Department of Burn & Burn Center, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Bing Ma
- Department of Burn & Burn Center, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Zhao-Fan Xia
- Department of Burn & Burn Center, Changhai Hospital, Second Military Medical University, Shanghai, China.
| |
Collapse
|
11
|
Al-Saffar H, Lewis K, Liu E, Schober A, Corrigan JJ, Shibata K, Steiner AA. Lipopolysaccharide-induced hypothermia and hypotension are associated with inflammatory signaling that is triggered outside the brain. Brain Behav Immun 2013. [PMID: 23207106 DOI: 10.1016/j.bbi.2012.11.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Little is known about the neuroimmune mechanisms responsible for the switch from fever to hypothermia observed in severe forms of systemic inflammation. We evaluated whether bacterial lipopolysaccharide (LPS) acting directly on the brain could promote a fever-hypothermia switch as well as the hypotension that is often associated with hypothermia in models of systemic inflammation. At an ambient temperature of 22°C, freely moving rats received intracerebroventricular (i.c.v.) injections of LPS at doses ranging from 0.5 to 25μg. Despite the use of such high doses, the prevailing thermal response was fever. To investigate if a hypothermic response could be hidden within the prevailing febrile response, rats were pretreated with a cyclooxygenase-2 inhibitor (SC-236, 3.5mg/kg i.v.) known to block fever, but this strategy also failed to reveal any consistent hypothermic response following i.c.v. LPS. At the doses tested, i.c.v. LPS was similarly ineffective at inducing hypotension. Additional doses of LPS did not need to be tested because the 25-μg dose was already sufficient to induce both hypothermia and hypotension when administered peripherally (intra-arterially). An empirical 3D model of the interplay among body temperature, arterial pressure and heart rate following intra-arterial LPS reinforced the strong association of hypothermia with hypotension and, at the same time, exposed a bell-shaped relationship between heart rate and body temperature. In summary, the present study demonstrates that hypothermia and hypotension are triggered exclusively by LPS acting outside the brain and provides an integrated model of the thermal and cardiovascular responses to peripheral LPS.
Collapse
Affiliation(s)
- Hiba Al-Saffar
- Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| | | | | | | | | | | | | |
Collapse
|
12
|
Mittag J, Lyons DJ, Sällström J, Vujovic M, Dudazy-Gralla S, Warner A, Wallis K, Alkemade A, Nordström K, Monyer H, Broberger C, Arner A, Vennström B. Thyroid hormone is required for hypothalamic neurons regulating cardiovascular functions. J Clin Invest 2012; 123:509-16. [PMID: 23257356 DOI: 10.1172/jci65252] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 10/18/2012] [Indexed: 12/18/2022] Open
Abstract
Thyroid hormone is well known for its profound direct effects on cardiovascular function and metabolism. Recent evidence, however, suggests that the hormone also regulates these systems indirectly through the central nervous system. While some of the molecular mechanisms underlying the hormone's central control of metabolism have been identified, its actions in the central cardiovascular control have remained enigmatic. Here, we describe a previously unknown population of parvalbuminergic neurons in the anterior hypothalamus that requires thyroid hormone receptor signaling for proper development. Specific stereotaxic ablation of these cells in the mouse resulted in hypertension and temperature-dependent tachycardia, indicating a role in the central autonomic control of blood pressure and heart rate. Moreover, the neurons exhibited intrinsic temperature sensitivity in patch-clamping experiments, providing a new connection between cardiovascular function and core temperature. Thus, the data identify what we believe to be a novel hypothalamic cell population potentially important for understanding hypertension and indicate developmental hypothyroidism as an epigenetic risk factor for cardiovascular disorders. Furthermore, the findings may be beneficial for treatment of the recently identified patients that have a mutation in thyroid hormone receptor α1.
Collapse
Affiliation(s)
- Jens Mittag
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Chan GSH, Tang CHH, Middleton PM, Cave G, Harvey M, Savkin AV, Lovell NH. Augmented photoplethysmographic low frequency waves at the onset of endotoxic shock in rabbits. Physiol Meas 2010; 31:1605-21. [DOI: 10.1088/0967-3334/31/12/004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
14
|
Central cannabinoid 1 receptor antagonist administration prevents endotoxic hypotension affecting norepinephrine release in the preoptic anterior hypothalamic area. Shock 2010; 32:614-20. [PMID: 19295473 DOI: 10.1097/shk.0b013e3181a4fd8f] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
It is widely assumed that LPS lowers arterial pressure during sepsis by stimulating release of TNF-alpha and other vasoactive mediators from macrophages. However, recent data from this and other laboratories have shown that LPS hypotension can be prevented by inhibiting afferent impulse flow in the vagus nerve, by blocking neuronal activity in the nucleus of the solitary tract, or by blocking alpha-adrenergic receptors in the preoptic area/anterior hypothalamic area (POA). These findings suggest that the inflammatory signal is conveyed from the periphery to the brain via the vagus nerve, and that endotoxic shock is mediated through a central mechanism that requires activation of POA neurons. In the present study, we tested whether central cannabinoid 1 (CB1) receptors participate in the control of arterial pressure during endotoxemia based on evidence that hypothalamic neurons express CB1 receptors and synthesize the endogenous CB anandamide. We found that intracerebroventricular administration of rimonabant, a CB1 receptor antagonist, inhibited the fall in arterial pressure evoked by LPS significantly in both conscious and anesthetized rats. Rimonabant attenuated both the immediate fall in arterial pressure evoked by LPS and the second, delayed hypotensive phase that leads to tissue ischemia and death. Rimonabant also prevented the associated LPS-induced rise in extracellular fluid norepinephrine concentrations in the POA. Furthermore, rimonabant attenuated the associated increase in plasma TNF-alpha concentrations characteristic of the late phase of endotoxic hypotension. These data indicate that central CB1 receptors may play an important role in the initiation of endotoxic hypotension.
Collapse
|
15
|
DellaGioia N, Hannestad J. A critical review of human endotoxin administration as an experimental paradigm of depression. Neurosci Biobehav Rev 2009; 34:130-43. [PMID: 19666048 DOI: 10.1016/j.neubiorev.2009.07.014] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 07/22/2009] [Accepted: 07/24/2009] [Indexed: 12/12/2022]
Abstract
The syndrome called depression may represent the common final pathway at which different aetiopathogenic processes converge. One such aetiopathogenic process is innate immune system activation. Some depressed patients have increased levels of inflammatory cytokines and other immunologic abnormalities. It is not known whether immune system activation contributes to the pathogenesis of depressive symptoms. Supporting this possibility is the observation that in both rodents and humans, exogenous immune stimuli such as endotoxin can produce symptoms that resemble depression. A new approach to depression research would be to use immune stimuli to elicit depressive symptoms in humans. Here we review each of the symptoms elicited in humans by endotoxin administration, and compare this model to two other immune depression paradigms: interferon-alpha treatment and typhoid vaccine administration, to assess to what degree endotoxin administration represents a valid model of immune depression. We also review corresponding behavioral changes in rodents and the potential molecular pathways through which immune system activation produces each symptom.
Collapse
Affiliation(s)
- Nicole DellaGioia
- Yale Department of Psychiatry, Clinical Neuroscience Research Unit, Yale University School of Medicine, New Haven, CT 06519, USA
| | | |
Collapse
|
16
|
Lipopolysaccharide-induced hypotension is mediated by a neural pathway involving the vagus nerve, the nucleus tractus solitarius and alpha-adrenergic receptors in the preoptic anterior hypothalamic area. J Neuroimmunol 2009; 203:39-49. [PMID: 18653249 DOI: 10.1016/j.jneuroim.2008.06.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 06/16/2008] [Accepted: 06/17/2008] [Indexed: 11/21/2022]
Abstract
We recently reported that the preoptic anterior hypothalamic area (POA) mediates the hypotensive response evoked by lipopolysaccharide (LPS). In this study, we investigated how the inflammatory signal induced by LPS reaches the POA. Subdiaphragmatic vagotomy and abdominal perivagal lidocaine administration, or lidocaine injection into the nucleus tractus solitarius (NTS) prevented LPS hypotension. Microinjection of the alpha-adrenergic receptor antagonist phentolamine into the POA, blocked initiation of the hypotensive response and prevented the late decompensatory phase. These data suggest that LPS hypotension is mediated by the vagus nerve which conveys the signal to the NTS and, in turn, stimulates norepinephrine release within the POA.
Collapse
|
17
|
What's new in Shock, February 2008? Shock 2008; 29:151-3. [PMID: 18204383 DOI: 10.1097/shk.0b013e318160f549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|