1
|
Tikhonova MA, Zhanaeva SY, Shvaikovskaya AA, Olkov NM, Aftanas LI, Danilenko KV. Neurospecific Molecules Measured in Periphery in Humans: How Do They Correlate with the Brain Levels? A Systematic Review. Int J Mol Sci 2022; 23:ijms23169193. [PMID: 36012459 PMCID: PMC9409387 DOI: 10.3390/ijms23169193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/09/2022] [Accepted: 08/13/2022] [Indexed: 11/19/2022] Open
Abstract
Human brain state is usually estimated by brain-specific substances in peripheral tissues, but, for most analytes, a concordance between their content in the brain and periphery is unclear. In this systematic review, we summarized the investigated correlations in humans. PubMed was searched up to June 2022. We included studies measuring the same endogenous neurospecific analytes in the central nervous system and periphery in the same subjects. Not eligible were studies of cerebrospinal fluid, with significant blood–brain barrier disruption, of molecules with well-established blood-periphery concordance or measured in brain tumors. Seventeen studies were eligible. Four studies did not report on correlation and four revealed no significant correlation. Four molecules were examined twice. For BDNF, there was no correlation in both studies. For phenylalanine, glutamine, and glutamate, results were contradictory. Strong correlations were found for free tryptophan (r = 0.97) and translocator protein (r = 0.90). Thus, only for three molecules was there some certainty. BDNF in plasma or serum does not reflect brain content, whereas free tryptophan (in plasma) and translocator protein (in blood cells) can serve as peripheral biomarkers. We expect a breakthrough in the field with advanced in vivo metabolomic analyses, neuroimaging techniques, and blood assays for exosomes of brain origin.
Collapse
|
2
|
The N-Methyl-D-Aspartate Receptor Blocker REL-1017 (Esmethadone) Reduces Calcium Influx Induced by Glutamate, Quinolinic Acid, and Gentamicin. Pharmaceuticals (Basel) 2022; 15:ph15070882. [PMID: 35890179 PMCID: PMC9319291 DOI: 10.3390/ph15070882] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 02/05/2023] Open
Abstract
REL-1017 (esmethadone) is a novel N-methyl-D-aspartate receptor (NMDAR) antagonist and promising rapid antidepressant candidate. Using fluorometric imaging plate reader (FLIPR) assays, we studied the effects of quinolinic acid (QA) and gentamicin, with or without L-glutamate and REL-1017, on intracellular calcium ([Ca2+]in) in recombinant cell lines expressing human GluN1-GluN2A, GluN1-GluN2B, GluN1-GluN2C, and GluN1-GluN2D NMDAR subtypes. There were no effects of QA on [Ca2+]in in cells expressing GluN1-GluN2C subtypes. QA acted as a low-potency, subtype-selective, NMDAR partial agonist in GluN1-GluN2A, GluN1-GluN2B, and GluN1-GluN2D subtypes. REL-1017 reduced [Ca2+]in induced by QA. In cells expressing the GluN1-GluN2D subtype, QA acted as an agonist in the presence of 0.04 μM L-glutamate and as an antagonist in the presence of 0.2 μM L-glutamate. REL-1017 reduced [Ca2+]in induced by L-glutamate alone and with QA in all cell lines. In the absence of L-glutamate, gentamicin had no effect. Gentamicin was a positive modulator for GluN1-GluN2B subtypes at 10 μM L-glutamate, for GluN1-GluN2A at 0.2 μM L-glutamate, and for GluN1-GluN2A, GluN1-GluN2B, and GluN1-GluN2D at 0.04 μM L-glutamate. No significant changes were observed with GluN1-GluN2C NMDARs. REL-1017 reduced [Ca2+]in induced by the addition of L-glutamate in all NMDAR cell lines in the presence or absence of gentamicin. In conclusion, REL-1017 reduced [Ca2+]in induced by L-glutamate alone and when increased by QA and gentamicin. REL-1017 may protect cells from excessive calcium entry via NMDARs hyperactivated by endogenous and exogenous molecules.
Collapse
|
3
|
Skorobogatov K, De Picker L, Verkerk R, Coppens V, Leboyer M, Müller N, Morrens M. Brain Versus Blood: A Systematic Review on the Concordance Between Peripheral and Central Kynurenine Pathway Measures in Psychiatric Disorders. Front Immunol 2021; 12:716980. [PMID: 34630391 PMCID: PMC8495160 DOI: 10.3389/fimmu.2021.716980] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 09/08/2021] [Indexed: 12/19/2022] Open
Abstract
Objective Disturbances in the kynurenine pathway have been implicated in the pathophysiology of psychotic and mood disorders, as well as several other psychiatric illnesses. It remains uncertain however to what extent metabolite levels detectable in plasma or serum reflect brain kynurenine metabolism and other disease-specific pathophysiological changes. The primary objective of this systematic review was to investigate the concordance between peripheral and central (CSF or brain tissue) kynurenine metabolites. As secondary aims we describe their correlation with illness course, treatment response, and neuroanatomical abnormalities in psychiatric diseases. Methods We performed a systematic literature search until February 2021 in PubMed. We included 27 original research articles describing a correlation between peripheral and central kynurenine metabolite measures in preclinical studies and human samples from patients suffering from neuropsychiatric disorders and other conditions. We also included 32 articles reporting associations between peripheral KP markers and symptom severity, CNS pathology or treatment response in schizophrenia, bipolar disorder or major depressive disorder. Results For kynurenine and 3-hydroxykynurenine, moderate to strong concordance was found between peripheral and central concentrations not only in psychiatric disorders, but also in other (patho)physiological conditions. Despite discordant findings for other metabolites (mainly tryptophan and kynurenic acid), blood metabolite levels were associated with clinical symptoms and treatment response in psychiatric patients, as well as with observed neuroanatomical abnormalities and glial activity. Conclusion Only kynurenine and 3-hydroxykynurenine demonstrated a consistent and reliable concordance between peripheral and central measures. Evidence from psychiatric studies on kynurenine pathway concordance is scarce, and more research is needed to determine the validity of peripheral kynurenine metabolite assessment as proxy markers for CNS processes. Peripheral kynurenine and 3-hydroxykynurenine may nonetheless represent valuable predictive and prognostic biomarker candidates for psychiatric disorders.
Collapse
Affiliation(s)
- Katrien Skorobogatov
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| | - Livia De Picker
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| | - Robert Verkerk
- Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium
| | - Violette Coppens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| | - Marion Leboyer
- INSERM U955, Equipe Psychiatrie Translationnelle, Créteil, France.,Fondation FondaMental - Hôpital Albert Chenevier - Pôle Psychiatrie, Créteil, France.,AP-HP, Hôpitaux Universitaires Henri Mondor, DHU Pepsy, Pôle de Psychiatrie et d'Addictologie, Créteil, France.,Université Paris Est Créteil, Faculté de Médecine, Creteil, France
| | - Norbert Müller
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, München, Germany
| | - Manuel Morrens
- Faculty of Medicine and Health Sciences, Collaborative Antwerp Psychiatric Research Institute (CAPRI), University of Antwerp, Antwerp, Belgium.,Scientific Initiative of Neuropsychiatric and Psychopharmacological Studies (SINAPS), University Psychiatric Centre Duffel, Duffel, Belgium
| |
Collapse
|
4
|
Santisukwongchote K, Amornlertwatana Y, Sastraruji T, Jaikang C. Possible Use of Blood Tryptophan Metabolites as Biomarkers for Coronary Heart Disease in Sudden Unexpected Death. Metabolites 2019; 10:E6. [PMID: 31861670 PMCID: PMC7022541 DOI: 10.3390/metabo10010006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/22/2019] [Accepted: 12/17/2019] [Indexed: 11/28/2022] Open
Abstract
Coronary heart disease (CHD) is the major cause of death in sudden unexpected death (SUD) cases. Tryptophan (TRP) and its metabolites are correlated with the CHD patient but less studies in the SUD. The aim of this study was to evaluate the relationship of TRP and its metabolites with the CHD in the SUD cases. Blood samples and heart tissues were collected from CHD subjects (n = 31) and the control group (n = 72). Levels of kynurenine (KYN), kynurenic acid (KYA), xanthurenic acid (XAN), 3-hydroxyanthranillic acid (HAA), quinolinic acid (QA), picolinic acid (PA) and 5-hydroxyindoleacetic acid (HIAA) were determined by HPLC-DAD. A severity of heart occlusion was categorized into four groups, and the relationship was measured with the TRP metabolites. The HIAA and The KYN levels significantly differed (p < 0.01) between the CHD group and the control group. Lower levels of QA/XAN, PA/KA, HAA/XAN, KYN/XAN and KYN/TRP were found in the CHD group. However, PA/HAA, PA/HIAA, PA/KYN and XAN/KA values in the CHD group were higher than the control group (p < 0.05). This study revealed that the values of PA/KA and PA/HAA provided better choices for a CHD biomarker in postmortem bodies.
Collapse
Affiliation(s)
- Kobchai Santisukwongchote
- Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Yutti Amornlertwatana
- Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Thanapat Sastraruji
- Center of Excellence in Oral and Maxillofacial Biology, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Churdsak Jaikang
- Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand;
| |
Collapse
|
5
|
Clària J, Moreau R, Fenaille F, Amorós A, Junot C, Gronbaek H, Coenraad MJ, Pruvost A, Ghettas A, Chu-Van E, López-Vicario C, Oettl K, Caraceni P, Alessandria C, Trebicka J, Pavesi M, Deulofeu C, Albillos A, Gustot T, Welzel TM, Fernández J, Stauber RE, Saliba F, Butin N, Colsch B, Moreno C, Durand F, Nevens F, Bañares R, Benten D, Ginès P, Gerbes A, Jalan R, Angeli P, Bernardi M, Arroyo V. Orchestration of Tryptophan-Kynurenine Pathway, Acute Decompensation, and Acute-on-Chronic Liver Failure in Cirrhosis. Hepatology 2019; 69:1686-1701. [PMID: 30521097 DOI: 10.1002/hep.30363] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 10/22/2018] [Indexed: 12/12/2022]
Abstract
Systemic inflammation (SI) is involved in the pathogenesis of acute decompensation (AD) and acute-on-chronic liver failure (ACLF) in cirrhosis. In other diseases, SI activates tryptophan (Trp) degradation through the kynurenine pathway (KP), giving rise to metabolites that contribute to multiorgan/system damage and immunosuppression. In the current study, we aimed to characterize the KP in patients with cirrhosis, in whom this pathway is poorly known. The serum levels of Trp, key KP metabolites (kynurenine and kynurenic and quinolinic acids), and cytokines (SI markers) were measured at enrollment in 40 healthy subjects, 39 patients with compensated cirrhosis, 342 with AD (no ACLF) and 180 with ACLF, and repeated in 258 patients during the 28-day follow-up. Urine KP metabolites were measured in 50 patients with ACLF. Serum KP activity was normal in compensated cirrhosis, increased in AD and further increased in ACLF, in parallel with SI; it was remarkably higher in ACLF with kidney failure than in ACLF without kidney failure in the absence of differences in urine KP activity and fractional excretion of KP metabolites. The short-term course of AD and ACLF (worsening, improvement, stable) correlated closely with follow-up changes in serum KP activity. Among patients with AD at enrollment, those with the highest baseline KP activity developed ACLF during follow-up. Among patients who had ACLF at enrollment, those with immune suppression and the highest KP activity, both at baseline, developed nosocomial infections during follow-up. Finally, higher baseline KP activity independently predicted mortality in patients with AD and ACLF. Conclusion: Features of KP activation appear in patients with AD, culminate in patients with ACLF, and may be involved in the pathogenesis of ACLF, clinical course, and mortality.
Collapse
Affiliation(s)
- Joan Clària
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain.,Hospital Clínic, IDIBAPS and CIBERehd, Barcelona, Spain
| | - Richard Moreau
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain.,Inserm, Centre de Recherche sur l'Inflammation, Université Paris Diderot-Paris, Département Hospitalo-Universitaire UNITY; Service d'Hépatologie, Hôpital Beaujon, Assistance Publique-Hôpitaux de Paris; Laboratoire d'Excellence Inflamex, ComUE Sorbonne Paris Cité, Paris, France
| | - François Fenaille
- CEA, INRA, Université Paris Saclay, Laboratoire d'Etude du Métabolisme des Médicaments, MetaboHUB-Paris, Gif-Sur-Yvette, France
| | - Alex Amorós
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain
| | - Christophe Junot
- CEA, INRA, Université Paris Saclay, Laboratoire d'Etude du Métabolisme des Médicaments, MetaboHUB-Paris, Gif-Sur-Yvette, France
| | - Henning Gronbaek
- Department of Hepatology & Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Minneke J Coenraad
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, the Netherlands
| | - Alain Pruvost
- CEA, INRA Université Paris Saclay, Service de Pharmacologie et Immunoanalyse, Plateforme SMArt-MS, Gif-sur-Yvette, France
| | - Aurélie Ghettas
- CEA, INRA Université Paris Saclay, Service de Pharmacologie et Immunoanalyse, Plateforme SMArt-MS, Gif-sur-Yvette, France
| | - Emeline Chu-Van
- CEA, INRA, Université Paris Saclay, Laboratoire d'Etude du Métabolisme des Médicaments, MetaboHUB-Paris, Gif-Sur-Yvette, France
| | | | - Karl Oettl
- Medical University of Graz, Graz, Austria
| | - Paolo Caraceni
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Carlo Alessandria
- Division of Gastroenterology and Hepatology, San Giovanni Battista Hospital, Torino, Italy
| | - Jonel Trebicka
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain.,Department of Internal Medicine I, University of Bonn, Bonn, Germany.,J.W. Goethe University Hospital, Frankfurt, Germany
| | - Marco Pavesi
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain
| | - Carme Deulofeu
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain
| | | | - Thierry Gustot
- CUB Hopital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Javier Fernández
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain.,Hospital Clínic, IDIBAPS and CIBERehd, Barcelona, Spain
| | | | - Faouzi Saliba
- Hôpital Paul Brousse, Université Paris-Sud, Villejuif, France
| | - Noémie Butin
- CEA, INRA, Université Paris Saclay, Laboratoire d'Etude du Métabolisme des Médicaments, MetaboHUB-Paris, Gif-Sur-Yvette, France
| | - Benoit Colsch
- CEA, INRA, Université Paris Saclay, Laboratoire d'Etude du Métabolisme des Médicaments, MetaboHUB-Paris, Gif-Sur-Yvette, France
| | - Christophe Moreno
- CUB Hopital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - François Durand
- Inserm, Centre de Recherche sur l'Inflammation, Université Paris Diderot-Paris, Département Hospitalo-Universitaire UNITY; Service d'Hépatologie, Hôpital Beaujon, Assistance Publique-Hôpitaux de Paris; Laboratoire d'Excellence Inflamex, ComUE Sorbonne Paris Cité, Paris, France
| | | | - Rafael Bañares
- Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | | | - Pere Ginès
- Hospital Clínic, IDIBAPS and CIBERehd, Barcelona, Spain
| | - Alexander Gerbes
- Department of Medicine II, University Hospital LMU Munich, Liver Center Munich, Munich, Germany
| | - Rajiv Jalan
- Liver Failure Group, Institute for Liver Disease Health, University College London, Royal Free Hospital, London, United Kingdom
| | - Paolo Angeli
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain.,Unit of Internal Medicine and Hepatology, Department of Medicine, DIMED, University of Padova, Padoa, Italy
| | - Mauro Bernardi
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Vicente Arroyo
- European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain
| | | |
Collapse
|
6
|
Fan Y, Liu X. Alterations in Expression and Function of ABC Family Transporters at Blood-Brain Barrier under Liver Failure and Their Clinical Significances. Pharmaceutics 2018; 10:pharmaceutics10030102. [PMID: 30041501 PMCID: PMC6161250 DOI: 10.3390/pharmaceutics10030102] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 07/20/2018] [Accepted: 07/21/2018] [Indexed: 02/07/2023] Open
Abstract
Liver failure is often associated with hepatic encephalopathy, due to dyshomeostasis of the central nervous system (CNS). Under physiological conditions, the CNS homeostasis is precisely regulated by the blood-brain barrier (BBB). The BBB consists of brain microvessel endothelial cells connected with a junctional complex by the adherens junctions and tight junctions. Its main function is to maintain brain homoeostasis via limiting the entry of drugs/toxins to brain. The brain microvessel endothelial cells are characterized by minimal pinocytotic activity, absent fenestrations, and highly expressions of ATP-binding cassette (ABC) family transporters (such as P-glycoprotein, breast cancer resistance protein and multidrug resistance-associated proteins). These ABC transporters prevent brain from toxin accumulation by pumping toxins out of brain. Accumulating evidences demonstrates that liver failure diseases altered the expression and function of ABC transporters at The BBB, indicating that the alterations subsequently affect drugs’ brain distribution and CNS activity/neurotoxicity. ABC transporters also mediate the transport of endogenous substrates across the BBB, inferring that ABC transporters are also implicated in some physiological processes and the development of hepatic encephalopathy. This paper focuses on the alteration in the BBB permeability, the expression and function of ABC transporters at the BBB under liver failure status and their clinical significances.
Collapse
Affiliation(s)
- Yilin Fan
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009, China.
| | - Xiaodong Liu
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009, China.
| |
Collapse
|
7
|
Badawy AAB. Hypothesis kynurenic and quinolinic acids: The main players of the kynurenine pathway and opponents in inflammatory disease. Med Hypotheses 2018; 118:129-138. [PMID: 30037600 DOI: 10.1016/j.mehy.2018.06.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/19/2018] [Accepted: 06/19/2018] [Indexed: 12/22/2022]
Abstract
I hypothesize that the intermediates of the kynurenine (Kyn) pathway (KP) of tryptophan (Trp) degradation kynurenic acid (KA) and quinolinic acid (QA) play opposite roles in inflammatory diseases, with KA being antiinflammatory and QA being immunosuppressant. Darlington et al. have demonstrated a decrease in the ratio of plasma 3-hydroxyanthranilic acid to anthranilic acid ([3-HAA]/[AA]) in many inflammatory conditions and proposed that this decrease either reflects inflammatory disease or is an antiinflammatory response. I argue in favour of the latter possibility and provide evidence that KA is responsible for the decrease in this ratio by increasing AA formation from Kyn through activation of the kynureninase reaction. Immunosuppression has been attributed to some Kyn metabolites tested at concentrations far greater than could occur in microenvironments. So far, only QA has been shown using immunohistochemistry to reach immunosuppressive levels. Future immune studies of the KP should focus on QA as the potentially main microenvironmentally measurable immunosuppressant and should include KA as an antiinflammatory metabolite.
Collapse
Affiliation(s)
- Abdulla A-B Badawy
- School of Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, Wales, UK.
| |
Collapse
|
8
|
Stange J, Mitzner S. A Carrier-Mediated Transport of Toxins in a Hybrid Membrane. Safety Barrier between a Patients Blood and a Bioartificial Liver. Int J Artif Organs 2018. [DOI: 10.1177/039139889601901109] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Combination of detoxifying liver support systems with liver cell bioreactors may have additional benefits for the treatment of liver failure due to the replacement of known and unknown metabolic activities of the liver. However, the problem of side effects and possible risks caused by the use of animal hepatocytes or hepatoma cells remains unsolved which underlines the need of a safety barrier between the patients blood and the extracorporeal bioreactor. Passive filters do not meet the requirements of such membranes, because in liver failure desired and undesired molecules in the patients blood share similar physicochemical properties. That challanges the developement of biologically designed separation membranes. A hybrid membrane is formed by implementation of transport proteins into a highly permeable hollow fiber. The transport of free solutes and albumin bound toxins is tested in vitro in comparison with conventional high flux membranes. The transport characteristics for tightly albumin bound toxins are significantly improved for the hybrid membrane. The transport of albumin bound toxins across the membrane is not associated with albumin. The selectivity of the transport is evaluated in vivo. No significant loss of middle molecular weight hormones attached to other carrier proteins was observed. Neither transport of immunologically relevant proteins across the membrane nor loss of valuable proteins was measured. Also in vivo, a significant reduction of protein bound toxins and a transport of metabolically relevant solutes, like amino acids, was shown. The presented hybrid membrane may be used like an “intellegent membrane” as a safety barrier between the patients blood and cell devices.
Collapse
Affiliation(s)
- J. Stange
- Department of Internal Medicine/HII, University of Rostock, Rostock - Germany
| | - S. Mitzner
- Department of Internal Medicine/HII, University of Rostock, Rostock - Germany
| |
Collapse
|
9
|
Eskelund A, Li Y, Budac DP, Müller HK, Gulinello M, Sanchez C, Wegener G. Drugs with antidepressant properties affect tryptophan metabolites differently in rodent models with depression-like behavior. J Neurochem 2017; 142:118-131. [DOI: 10.1111/jnc.14043] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/28/2017] [Accepted: 04/04/2017] [Indexed: 12/17/2022]
Affiliation(s)
| | - Yan Li
- Lundbeck Research US; Paramus New Jersey USA
| | | | | | - Maria Gulinello
- Behavioral Core Facility; Department of Neuroscience; Albert Einstein College of Medicine; Bronx New York USA
| | - Connie Sanchez
- Translational Neuropsychiatry Unit; Risskov Denmark
- Lundbeck Research US; Paramus New Jersey USA
| | | |
Collapse
|
10
|
Stone TW, Forrest CM, Mackay GM, Stoy N, Darlington LG. Tryptophan, adenosine, neurodegeneration and neuroprotection. Metab Brain Dis 2007; 22:337-52. [PMID: 17712616 DOI: 10.1007/s11011-007-9064-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This review summarises the potential contributions of two groups of compounds to cerebral dysfunction and damage in metabolic disease. The kynurenines are oxidised metabolites of tryptophan, the kynurenine pathway being the major route for tryptophan catabolism in most tissues. The pathway includes quinolinic acid -- an agonist at N-methyl-D-aspartate (NMDA) receptors, kynurenic acid -- an antagonist at glutamate and nicotinic receptors, and other redox active compounds that are able to generate free radicals under many physiological and pathological conditions. The pathway is activated in immune-competent cells, including glia in the central nervous system, and may contribute substantially to delayed neuronal damage following an infarct or metabolic insult. Adenosine is an ubiquitous purine that can protect neurons by suppressing excitatory neurotransmitter release, reducing calcium fluxes and inhibiting NMDA receptors. The extent of brain injury is critically dependent on the balance between the two opposing forces of kynurenines and purines.
Collapse
Affiliation(s)
- T W Stone
- Institute of Biomedical & Life Sciences, West Medical Building, University of Glasgow, Glasgow, Scotland, UK.
| | | | | | | | | |
Collapse
|
11
|
Ozdemir FN, Tutal E, Sezer S, Gür G, Bilgic A, Haberal M. Effect of supportive extracorporeal treatment in liver transplantation recipients and advanced liver failure patients. Hemodial Int 2007; 10 Suppl 2:S28-32. [PMID: 17022748 DOI: 10.1111/j.1542-4758.2006.00113.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently, continuous venovenous hemodiafiltration (CVVHDF) and plasmapheresis (PF) were suggested as supportive therapy options in combination with standard treatment in advanced liver failure. The aim of this study was to analyze the effects of supportive extracorporeal treatment (SET) in a group of patients with advanced hepatic failure. A total of 25 patients (7 women, 18 men; mean age, 39.3+/-15.4 years; 13 were transplant recipients [6 women, 7 men; mean age, 37.7+/-16.9 years]) were included. All patients were in hepatic coma and receiving standard coma and liver failure management when they received SET. Number of SET sessions; levels of serum blood urea nitrogen, creatinine, albumin, calcium, phosphorus, ammonia, alanine and aspartate aminotransferase, and total/conjugated bilirubin; and prothrombin times (PTT) before and after SET were recorded retrospectively. 7.7+/-7.9 SET sessions were performed. Thirteen liver transplant recipients required SET for an average of 9.7+/-8.3 days after transplantation. Serum ammonia and bilirubin levels were lower after termination of supportive therapy when compared with initial levels (p<0.0001 and p<0.005 respectively). During follow-up, hepatic encephalopathy and liver failure resolved in 11 patients, while 14 patients (7 transplant recipients) died. There was no significant difference between patients in either group except that PTT was shorter in patients who survived (p<0.01). Further analyses revealed that in surviving patients, ammonia clearance was higher (p<0.01). In patients with advanced liver failure, or liver transplants, CVVHDF and/or PF could be supportive options combined with standard treatment.
Collapse
Affiliation(s)
- Fatma N Ozdemir
- Department of Nephrology, Baskent University Hospital, Ankara, Turkey
| | | | | | | | | | | |
Collapse
|
12
|
Sathyasaikumar KV, Swapna I, Reddy PVB, Murthy CRK, Roy KR, Dutta Gupta A, Senthilkumaran B, Reddanna P. Co-administration of C-Phycocyanin ameliorates thioacetamide-induced hepatic encephalopathy in Wistar rats. J Neurol Sci 2006; 252:67-75. [PMID: 17169376 DOI: 10.1016/j.jns.2006.10.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 09/19/2006] [Accepted: 10/10/2006] [Indexed: 12/21/2022]
Abstract
Fulminant hepatic failure (FHF) is a condition with a sudden onset of necrosis followed by degeneration of hepatocytes, without any previously established liver disease, generally occurring within hours or days. FHF is associated with a wide spectrum of neuropsychiatric alterations ranging from stupor to coma, culminating in death. In the present study FHF was induced in rats by the administration of thioacetamide (TAA). Oxidative stress is thought to play a prominent role in the pathophysiology of cerebral changes during FHF leading to the assumption that antioxidants might offer protection. Hence, in the present study the protective effect of C-Phycocyanin (C-PC), a natural antioxidant, was evaluated on TAA-induced tissue damage. C-Phycocyanin was administered intraperitoneally twice at 24 h interval (50 mg/kg body weight) along with the hepatotoxin TAA (300 mg/kg body weight). The animals were sacrificed 18 h after the second injection of TAA treatment and various biochemical parameters were analysed in liver, serum and brain tissues. These studies revealed significant prevention of TAA-induced liver damage by C-PC, as evidenced by a) increase in survival rate; b) the prevention of leakage of liver enzymes (AAT and AST) and ammonia into serum; c) increase in prothrombin time and d) liver histopathology. Ultrastructural studies of astrocytes of different regions of brain clearly showed a decrease in edema after C-PC treatment. TAA-induced histopathological lesions in different regions of the brain namely cerebral cortex, cerebellum and pons medulla were significantly reduced by the co-administration of C-PC with TAA. Further C-PC treatment resulted in a) decrease in the levels of tryptophan and markers of lipid peroxidation and b) elevation in the activity levels of catalase, glutathione peroxidase in different regions of brain. These studies reveal the potential of C-PC in ameliorating TAA-induced hepatic encephalopathy by improving antioxidant defenses.
Collapse
Affiliation(s)
- K V Sathyasaikumar
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Hyderabad-500 046, India
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Biancofiore G, Bindi LM, Urbani L, Catalano G, Mazzoni A, Scatena F, Mosca F, Filipponi F. Combined twice-daily plasma exchange and continuous veno-venous hemodiafiltration for bridging severe acute liver failure. Transplant Proc 2004; 35:3011-4. [PMID: 14697964 DOI: 10.1016/j.transproceed.2003.10.077] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Aiming to remove the toxins produced during the course of severe hepatic failure, we combined hemodiafiltration and plasma exchange (patient plasma replaced by fresh frozen plasma in a twice-daily regimen) for treatment of five patients: two affected by primary nonfunction of a liver graft and three by fulminant hepatic failure. The simultaneous use of the two extracorporeal techniques allowed a rapid reduction in the administration of vasoactive drugs and a rapid, significant decrease in the indices of liver necrosis. Native liver functional recovery occurred in one case, and the wait for a second graft was made possible in the other four. Although it has been reported that the detoxifying efficacy of plasma exchange is optimal when the replaced volume of plasma is high, such a technique requires both long treatment times and high blood flows in the extracorporeal circuit, making it often hemodynamically intolerable. Our approach leads to replacement of smaller volumes, allowing lower blood flows that are better tolerated despite the often unstable hemodynamics of these patients. Liver transplantation and retransplantation remains the definite therapy for severe liver failure or primary nonfunction. However, the organ waiting time is unpredictable and often does not coincide with the patients' clinical needs. Thus alternative strategies must be developed until a suitable donor is found or there is spontaneous recovery. From this point of view, in our albeit limited experience, twice-daily plasma exchange combined with hemodiafiltration has proved to be an effective therapeutic approach.
Collapse
Affiliation(s)
- G Biancofiore
- Department of Anaesthesia and Intensive-Care, Azienda Ospedaliera Universitaria, Paradisa 2, Pisa 56100, Italy
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Ohashi H, Saito K, Fujii H, Wada H, Furuta N, Takemura M, Maeda S, Seishima M. Changes in quinolinic acid production and its related enzymes following D-galactosamine and lipopolysaccharide-induced hepatic injury. Arch Biochem Biophys 2004; 428:154-9. [PMID: 15246871 DOI: 10.1016/j.abb.2004.05.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Revised: 05/24/2004] [Indexed: 11/23/2022]
Abstract
Increases in quinolinic acid (QUIN), a neurotoxic L-tryptophan metabolite, have been observed in human serum and cerebrospinal fluid and in animal models of severe hepatic injury. The aim of this study was to evaluate the changes in QUIN accumulation and its related enzymes after acute hepatic injury induced by D-galactosamine and endotoxin. Gerbils were given an intraperitoneal injection of pyrogen-free saline alone as control, lipopolysaccharide (LPS) alone (150 ng/kg), D-galactosamine alone (500 mg/kg) or a combination of D-galactosamine with LPS. Concentrations of QUIN, its related metabolites, and related enzyme activities were determined. D-Galactosamine treatment significantly decreased activities of hepatic aminocarboxymuconate-semialdehyde decarboxylase (ACMSDase) resulting in increased QUIN concentrations in serum and tissues. The magnitude of QUIN responses was markedly increased by endotoxin due to the increased availability of L-kynurenine, a rate-limiting substrate for QUIN synthesis. Further, infiltration of monocytes/macrophages, which is a possible major source of QUIN production in the liver, was shown by immunohistochemistry after hepatic injury induced by D-galactosamine and endotoxin. Increased serum QUIN concentrations are probably due to the increased substrate availability and the decreased activity of aminocarboxymuconate-semialdehyde decarboxylase in the liver, accompanying the increased monocyte/macrophage infiltration into the liver after hepatic injury.
Collapse
Affiliation(s)
- Hazuki Ohashi
- Department of Informative Clinical Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Kramer L, Bauer E, Schenk P, Steininger R, Vigl M, Mallek R. Successful treatment of refractory cerebral oedema in ecstasy/cocaine-induced fulminant hepatic failure using a new high-efficacy liver detoxification device (FPSA-Prometheus). Wien Klin Wochenschr 2003; 115:599-603. [PMID: 14531175 DOI: 10.1007/bf03040456] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ecstasy-induced fulminant hepatic failure is associated with high mortality. If complicated by cerebral oedema, orthotopic liver transplantation is the only established treatment. We report a case of combined ecstasy/cocaine-induced fulminant hepatic failure presenting with severe rhabdomyolysis, myocardial infarction and multiorgan failure. Transplantation was declined by the transplant surgeons because of a history of intravenous drug abuse. As excessive hyperammonaemia (318 mumol/l) and refractory transtentorial herniation developed, treatment with a new liver detoxification device combining high-flux haemodialysis and adsorption (FPSA-Prometheus) was initiated. Within a few hours of treatment, ammonia levels normalised. Cerebral oedema was greatly reduced by day 4 and hepatic function gradually recovered. Following neurologic rehabilitation for ischaemic sequelae of herniation, the patient was discharged from hospital with only minimal deficits. In conclusion, efficient extracorporeal detoxification may be an option for reversal of hyperammonaemia and refractory cerebral oedema in ecstasy/cocaine-induced acute liver failure.
Collapse
Affiliation(s)
- Ludwig Kramer
- Department of Medicine IV, University of Vienna Medical School, Vienna, Austria.
| | | | | | | | | | | |
Collapse
|
16
|
Kramer L, Bauer E. Extracorporeal treatment in fulminant hepatic failure: pathophysiologic considerations. Int J Artif Organs 2002; 25:929-34. [PMID: 12456033 DOI: 10.1177/039139880202501006] [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] [Indexed: 02/01/2023]
Abstract
Fulminant hepatic failure is a life-threatening clinical syndrome following severe hepatic injury leading to cerebral edema and brainstem herniation. Excessive mortality can be currently reduced only by timely orthotopic liver transplantation. Due to the shortage of donor organs, a considerable proportion of patients develop irreversible neurological damage, multiorgan failure or death while waiting for transplantation. Consequently, alternatives to orthotopic liver transplantation and methods of stabilizing patients on the waiting list including extracorporeal detoxification treatment are currently investigated. Recent advances in the pathophysiology of cerebral edema have challenged some of the traditional assumptions on which many blood detoxification systems are based. This article aims to integrate pathophysiology of hepatic encephalopathy and cerebral edema into a proposed future concept of liver support.
Collapse
Affiliation(s)
- L Kramer
- Department of Medicine IV, University of Vienna Medical School, Vienna, Austria.
| | | |
Collapse
|
17
|
Abstract
In just under 20 years the kynurenine family of compounds has developed from a group of obscure metabolites of the essential amino acid tryptophan into a source of intensive research, with postulated roles for quinolinic acid in neurodegenerative disorders, most especially the AIDS-dementia complex and Huntington's disease. One of the kynurenines, kynurenic acid, has become a standard tool for use in the identification of glutamate-releasing synapses, and has been used as the parent for several groups of compounds now being developed as drugs for the treatment of epilepsy and stroke. The kynurenines represent a major success in translating a basic discovery into a source of clinical understanding and therapeutic application, with around 3000 papers published on quinolinic acid or kynurenic acid since the discovery of their effects in 1981 and 1982. This review concentrates on some of the recent work most directly relevant to the understanding and applications of kynurenines in medicine.
Collapse
Affiliation(s)
- T W Stone
- Institute of Biomedical and Life Sciences, University West Medical Building, University of Glasgow, Glasgow G12 8QQ, UK.
| |
Collapse
|
18
|
Kramer L, Gendo A, Madl C, Ferrara I, Funk G, Schenk P, Sunder-Plassmann G, Hörl WH. Biocompatibility of a cuprophane charcoal-based detoxification device in cirrhotic patients with hepatic encephalopathy. Am J Kidney Dis 2000; 36:1193-200. [PMID: 11096044 DOI: 10.1053/ajkd.2000.19834] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Extracorporeal detoxification has been proposed to treat patients with hepatic encephalopathy (HE) not responding to standard therapy. To investigate the biocompatibility of a cuprophane charcoal-based detoxification device, a prospective, randomized, controlled study was performed. Of 41 consecutive patients with cirrhosis and HE grade II or III who did not improve with conventional treatment, 20 patients (median age, 56 years; range, 33 to 71 years; 13 men) were randomly assigned to either ongoing conventional treatment or one additional 6-hour treatment with a sorbent suspension dialysis system. Main outcome parameters were physiological function and blood parameters of biocompatibility. In the 10 patients undergoing combined conventional and sorbent suspension dialysis treatment, blood pressure remained unchanged and body temperature and heart rate increased (P: < 0.01). Platelet count decreased (medians, from 75 to 26 g/L; P: < 0.001) and international normalized ratio increased after combined treatment (2.0 to 2.2; P: < 0.001). Three patients developed bleeding complications during treatment or shortly after. Treated patients showed increases in levels of plasma elastase (104 to 586 microg/L; P: = 0.001), tumor necrosis factor-alpha (5.4 to 7.5 pg/mL; P: = 0.04), and interleukin-6 (118 to 139 pg/mL; P: = 0.04), but not interferon-gamma and E-selectin. No changes were observed in the 10 patients treated conventionally. In conclusion, despite technical refinements compared with charcoal hemoperfusion, biocompatibility of sorbent suspension dialysis is still very limited. Clinical complications were apparently caused by blood-membrane interactions and disseminated intravascular coagulation. We suggest further developments in design and appropriate strategies of anticoagulation to improve the biocompatibility of artificial liver support.
Collapse
Affiliation(s)
- L Kramer
- Department of Medicine IV, Intensive Care Unit, University of Vienna, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Bengtsson F. Brain tryptophan/serotonin perturbations in metabolic encephalopathy and the hazards involved in the use of psychoactive drugs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 467:139-54. [PMID: 10721051 DOI: 10.1007/978-1-4615-4709-9_20] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Several combined pathogenetic factors such as hyperammonemia, different brain tryptophan metabolic disturbances and serotonin physiological/pharmacological alterations not yet defined in all details, will often give rise to the clinical neuropsychiatric condition known as hepatic encephalopathy (HE). Indeed, to this the probable exposure to novel potent CNS-monoamine acting drugs today may put such patients at certain risk for other pharmacodynamic (PD) responses than usually are expected from these "safe" drugs. Moreover, with a compromised liver function in HE, also pharmacokinetic (PK) features for the drugs are likely changed in these patients. Thus, the ultimate clinical outcome by this probable but unknown PD/PK-deviation for such psychoactive drugs when given to HE-patients needs further clarification. Accordingly, delineation of both PD- and PK-effects in experimental HE should shed light on this issue of relevance for monoamine-active drug safety as well as on some further details in the complex tryptophan/monoamine-related pathophysiology that comes into play in HE.
Collapse
Affiliation(s)
- F Bengtsson
- Department of Psychiatry, University Hospital, Linköping, Sweden.
| |
Collapse
|
20
|
Heyes MP, Saito K, Lackner A, Wiley CA, Achim CL, Markey SP. Sources of the neurotoxin quinolinic acid in the brain of HIV‐1‐infected patients and retrovirus‐infected macaques. FASEB J 1998. [DOI: 10.1096/fasebj.12.10.981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Melvyn P. Heyes
- Laboratory of NeurotoxicologyNational Institute of Mental Health Bethesda 20892 Maryland USA
| | - Kuniaki Saito
- Laboratory of NeurotoxicologyNational Institute of Mental Health Bethesda 20892 Maryland USA
| | - Andrew Lackner
- New England Regional Primate Research CenterHarvard Medical School Southborough 01772 Massachusetts USA
| | - Clayton A. Wiley
- Neuropathology DivisionPresbyterian‐University Hospital Pittsburgh 15213 Pennsylvania USA
| | - Cristian L. Achim
- Neuropathology DivisionPresbyterian‐University Hospital Pittsburgh 15213 Pennsylvania USA
| | - Sanford P. Markey
- Laboratory of NeurotoxicologyNational Institute of Mental Health Bethesda 20892 Maryland USA
| |
Collapse
|
21
|
Heyes MP, Saito K, Lackner A, Wiley CA, Achim CL, Markey SP. Sources of the neurotoxin quinolinic acid in the brain of HIV-1-infected patients and retrovirus-infected macaques. FASEB J 1998; 12:881-96. [PMID: 9657528 DOI: 10.1096/fasebj.12.10.881] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study investigated the sources of quinolinic acid, a neurotoxic tryptophan-kynurenine pathway metabolite, in the brain and blood of HIV-infected patients and retrovirus-infected macaques. In brain, quinolinic acid concentrations in HIV-infected patients were elevated by > 300-fold to concentrations that exceeded cerebrospinal fluid (CSF) by 8.9-fold. There were no significant correlations between elevated serum quinolinic acid levels with those in CSF and brain parenchyma. Because nonretrovirus-induced encephalitis confounds the interpretation of human postmortem data, rhesus macaques infected with retrovirus were used to examine the mechanisms of increased quinolinic acid accumulations and determine the relationships of quinolinic acid to encephalitits and systemic responses. The largest kynurenine pathway responses in brain were associated with encephalitis and were independent of systemic responses. CSF quinolinic acid levels were also elevated in all infected macaques, but particularly those with retrovirus-induced encephalitis. In contrast to the brain changes, there was no difference in any systemic measure between macaques with encephalitis vs. those without. Direct measures of the amount of quinolinic acid in brain derived from blood in a macaque with encephalitis showed that almost all quinolinic acid (>98%) was synthesized locally within the brain. These results demonstrate a role for induction of indoleamine-2,3dioxygenase in accelerating the local formation of quinolinic acid within the brain tissue, particularly in areas of encephalitis, rather than entry of quinolinic acid into the brain from the meninges or blood. Strategies to reduce QUIN production, targeted at intracerebral sites, are potential approaches to therapy.
Collapse
Affiliation(s)
- M P Heyes
- Laboratory of Neurotoxicology, National Institute of Mental Health, Bethesda, Maryland 20892, USA
| | | | | | | | | | | |
Collapse
|
22
|
Stastný F, Dvoráková L, Lisý V. Biochemical characteristics of gamma-glutamyl transpeptidase in capillaries from entorhinohippocampal complex of quinolinate-lesioned rat brain. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1997; 32:143-61. [PMID: 9437664 DOI: 10.1007/bf02815173] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Quinolinic acid (QUIN) is an endogenous excitotoxic agonist of the N-methyl-D-aspartate (NMDA) type of glutamate receptor, which causes slowly progressing degeneration of vulnerable neurons in some brain regions. Using changes in the activity of membrane-bound gamma-glutamyl transpeptidase (GGT) as a marker of cell damage, we found a significant decrease of this enzyme activity, which was preferentially located in the ipsilateral hippocampal formation and entorhinal cortex, 4 d after the unilateral intracerebroventricular (icv) injection of 0.5 mumol QUIN. The dose of QUIN divided into two half-doses injected bilaterally led to a symmetrical decline of GGT activity in hippocampal areas. The lesion was characterized by a suppression of GGT activity in hippocampal and entorhinal capillaries, corresponding to 60 and 81% of their initial value, respectively, but no significant changes were ascertained in synaptosomal membranes. The changes in the activity of capillary GGT were associated with the decrease of apparent maximal velocity Vmaxapp, whereas apparent Michaelis constant K(m)app (0.69-0.79 mM) remained unaffected. In the nonlesioned brain, concanavalin A (Con A) affinity chromatography revealed five glycoforms of synaptosomal GGT in contrast to only one found in hippocampal and entorhinal capillaries. The results document that neither the saccharide moiety of GGT nor the value of enzyme K(m)app is significantly affected by the QUIN-induced lesion of the rat brain. However, the suppression of GGT activity, which is accompanied by a decrease in the value of Vmaxapp in brain microvessels, may suggest dysfunction of the blood-brain barrier (BBB) in the QUIN-injured rat brain.
Collapse
Affiliation(s)
- F Stastný
- Department of Molecular Neurobiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
| | | | | |
Collapse
|
23
|
Dobbie MS, Surtees RA. Concentrations of quinolinic acid in cerebrospinal fluid measured by gas chromatography and electron-impact ionisation mass spectrometry. Age-related changes in a paediatric reference population. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 696:53-8. [PMID: 9300908 DOI: 10.1016/s0378-4347(97)00221-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A simple method for the determination of the excitotoxin, quinolinic acid (QUIN) in cerebrospinal fluid (CSF) is described. QUIN, in lyophilized samples, was silylated by N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide in a single-step reaction at 65 to 70 degrees C to form a di-tert.-butyldimethylsilyl ester. Neither pre-purification of QUIN from CSF nor post-derivatisation sample clean-up was required. The derivatives were analysed by gas chromatography-electron impact mass spectrometry resulting in a prominent and characteristic [M-57]+ fragment ion which was used for quantitation. 2,6-Pyridine dicarboxylic acid, a structural analog of QUIN, was used as the internal standard. The detection limits for injected standards are in the femtomole range. CSF QUIN was found to be age-related and three preliminary reference ranges for CSF QUIN were found: 0 to 1 years, 31 +/- 15 nM QUIN (mean +/- standard deviation): 1.1 to 3 years, 26 +/- 15 nM; 3.1 to 14 years, 14 +/- 9 nM.
Collapse
Affiliation(s)
- M S Dobbie
- Division of Biochemistry and Genetics, Institute of Child Health (UCLMS), London, UK
| | | |
Collapse
|
24
|
Bengtsson F, Bergqvist PB, Apelqvist G. Brain tryptophan perturbation in hepatic encephalopathy: implications for effects by neuropsychoactive drugs in clinical practice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 420:1-33. [PMID: 9286423 DOI: 10.1007/978-1-4615-5945-0_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- F Bengtsson
- Department of Clinical Pharmacology, Lund University Hospital, Sweden
| | | | | |
Collapse
|
25
|
Bengtsson F, Bergqvist P. Neuropsychiatric implications of brain tryptophan perturbations appearing in hepatic encephalopathy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 398:387-95. [PMID: 8906294 DOI: 10.1007/978-1-4613-0381-7_60] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- F Bengtsson
- Department of Clinical Pharmacology, Lund University Hospital, Sweden
| | | |
Collapse
|
26
|
Bergqvist PB, Heyes MP, Bengtsson F. Is quinolinic acid involved in the pathogenesis of hepatic encephalopathy? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 398:397-405. [PMID: 8906295 DOI: 10.1007/978-1-4613-0381-7_61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- P B Bergqvist
- Department of Clinical Pharmacology, Lund University Hospital, Sweden
| | | | | |
Collapse
|