1
|
Xiang Z, Xu XH, Knight GE, Burnstock G. Transient expression of thyrotropin releasing hormone peptide and mRNA in the rat hippocampus following global cerebral ischemia/reperfusion injury. Int J Neurosci 2020; 132:787-801. [PMID: 33080155 DOI: 10.1080/00207454.2020.1840374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION The role of extra-hypothalamic thyrotropin-releasing hormone (TRH) has been investigated by pharmacological studies using TRH or its analogues and found to produce a wide array of effects in the central nervous system. METHODS Immunofluorescence, In situ labeling of DNA (TUNEL), in situ hybridization chain reaction and quantitative real-time polymerase chain reaction were used in this study. RESULTS We found that the granular cells of the dentate gyrus expressed transiently a significant amount of TRH-like immunoreactivity and TRH mRNA during the 6-24 h period following global cerebral ischemia/reperfusion injury. TUNEL showed that apoptosis of neurons in the CA1 region occurred from 48 h and almost disappeared at 7 days. TRH administration 30 min before or 24 h after the injury could partially inhibit neuronal loss, and improve the survival of neurons in the CA1 region. CONCLUSION These data suggest that endogenous TRH expressed transiently in the dentate gyrus of the hippocampus may play an important role in the survival of neurons during the early stage of ischemia/reperfusion injury and that delayed application of TRH still produced neuroprotection. This delayed application of TRH has a promising therapeutic significance for clinical situations.
Collapse
Affiliation(s)
- Zhenghua Xiang
- Department of Neurobiology, MOE Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, Shanghai, PR China
| | - Xiao-Hui Xu
- School of Life Science, Shanghai University, Shanghai, People's Republic of China
| | - Gillian E Knight
- Autonomic Neuroscience Centre, University College Medical School, London
| | - Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, London.,Department of Pharmacology and Therapeutics, The University of Melbourne, Australia
| |
Collapse
|
2
|
Wackerlig J, Köfeler HC, Korz V, Hussein AM, Feyissa DD, Höger H, Urban E, Langer T, Lubec G, Lubec J. Differences in Hypothalamic Lipid Profiles of Young and Aged Male Rats With Impaired and Unimpaired Spatial Cognitive Abilities and Memory. Front Aging Neurosci 2020; 12:204. [PMID: 32719597 PMCID: PMC7349000 DOI: 10.3389/fnagi.2020.00204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022] Open
Abstract
Lipids play a major role for several brain functions, including cognition and memory. There is a series of work on individual lipids showing involvement in memory mechanisms, a concise lipidome was not reported so far. Moreover, there is no evidence for age-related memory decline and there is only work on brain of young vs. aging animals. Aging animals, however, are not a homogeneous group with respect to memory impairments, thus animals with impaired and unimpaired memory can be discriminated. Following recent studies of hippocampal lipid profiles and hypothalamus controlled hormone profiles, the aim of this study was to compare hypothalamic, lipidomic changes in male Sprague-Dawley rats between young (YM), old impaired (OMI) and old unimpaired (OMU) males. Grouping criterions for aged rats were evaluated by testing them in a spatial memory task, the hole-board. YMs were also tested. Subsequently brains were removed, dissected and hypothalami were kept at −80°C until sample preparation and analysis on liquid chromatography / mass spectrometry (LC-MS). Significant differences in the amounts of a series of lipids from several classes could be detected between young and aged and between OMI and OMU. A large number of lipids were increased in OMI and a smaller number in OMU as compared to young rats. Differences of lipid ratios (log2 of ratio) between OMI and OMU consisted of glycerophosphocholines (aPC 36:2 and 36:3; PC 34:0, 36:1, 36:3 and 40:2); Glycerophosphoethanolamines (aPE 34:2, 38:5 and 40:5; LPE 18:1, 20:1, 20:4, 22:4 and 22:6; PE36:1 and 38:4); glycerophosphoserines (PS 36:1, 40:4, and 40:6); triacylglycerol TG 52:4; ceramide Cer 17:2 and sphingomyelin SM 20:0. Thus, hypothalamic lipid profiles across different lipid classes discriminate aged male animals into OMU and OMI. The underlying mechanisms may be related to different functional networks of lipids in memory mechanisms and differences in metabolic processes. The study underlines the importance of lipidomics in the pathophysiology of age-related cognitive decline. The necessity of evaluating the cognitive status of aged subjects by behavioral tests results in more specific detection of critical lipids in memory decline, on which now can be focused in subsequent memory studies in animals and humans.
Collapse
Affiliation(s)
- Judith Wackerlig
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Harald C Köfeler
- Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Volker Korz
- Department of Neuroproteomics, Paracelsus Private Medical University, Salzburg, Austria
| | - Ahmed M Hussein
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Daniel D Feyissa
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Vienna, Austria
| | - Ernst Urban
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Thierry Langer
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Gert Lubec
- Neuroscience Laboratory, Paracelsus Medical University, Salzburg, Austria
| | - Jana Lubec
- Neuroscience Laboratory, Paracelsus Medical University, Salzburg, Austria
| |
Collapse
|
3
|
Waniek A, Hartlage-Rübsamen M, Höfling C, Kehlen A, Schilling S, Demuth HU, Roßner S. Identification of thyrotropin-releasing hormone as hippocampal glutaminyl cyclase substrate in neurons and reactive astrocytes. Biochim Biophys Acta Mol Basis Dis 2014; 1852:146-55. [PMID: 25446989 DOI: 10.1016/j.bbadis.2014.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/29/2014] [Accepted: 11/11/2014] [Indexed: 01/07/2023]
Abstract
Recently, Aβ peptide variants with an N-terminal truncation and pyroglutamate modification were identified and shown to be highly neurotoxic and prone to aggregation. This modification of Aβ is catalyzed by glutaminyl cyclase (QC) and pharmacological inhibition of QC diminishes Aβ deposition and accompanying gliosis and ameliorates memory impairment in transgenic mouse models of Alzheimer's disease (AD). QC expression was initially described in the hypothalamus, where thyrotropin-releasing hormone (TRH) is one of its physiological substrates. In addition to its hormonal role, a novel neuroprotective function of TRH following excitotoxicity and Aβ-mediated neurotoxicity has been reported in the hippocampus. Functionally matching this finding, we recently demonstrated QC expression by hippocampal interneurons in mouse brain. Here, we detected neuronal co-expression of QC and TRH in the hippocampus of young adult wild type mice using double immunofluorescence labeling. This provides evidence for TRH being a physiological QC substrate in hippocampus. Additionally, in neocortex of aged but not of young mice transgenic for amyloid precursor protein an increase of QC mRNA levels was found compared to wild type littermates. This phenomenon was not observed in hippocampus, which is later affected by Aβ pathology. However, in hippocampus of transgenic - but not of wild type mice - a correlation between QC and TRH mRNA levels was revealed. This co-regulation of the enzyme QC and its substrate TRH was reflected by a co-induction of both proteins in reactive astrocytes in proximity of Aβ deposits. Also, in primary mouse astrocytes a co-induction of QC and TRH was demonstrated upon Aβ stimulation.
Collapse
Affiliation(s)
- Alexander Waniek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Germany
| | | | - Corinna Höfling
- Paul Flechsig Institute for Brain Research, University of Leipzig, Germany
| | - Astrid Kehlen
- Institute for Medical Microbiology, Martin-Luther-University Halle-Wittenberg, Germany
| | - Stephan Schilling
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT Halle, Germany
| | - Hans-Ulrich Demuth
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT Halle, Germany.
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Germany.
| |
Collapse
|
4
|
Rajput SK, Siddiqui MA, Kumar V, Meena CL, Pant AB, Jain R, Sharma SS. Protective effects of L-pGlu-(2-propyl)-L-His-L-ProNH2, a newer thyrotropin releasing hormone analog in in vitro and in vivo models of cerebral ischemia. Peptides 2011; 32:1225-31. [PMID: 21515320 DOI: 10.1016/j.peptides.2011.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 04/05/2011] [Accepted: 04/07/2011] [Indexed: 12/31/2022]
Abstract
In the present study, the newly synthesized TRH analog (L-pGlu-(2-propyl)-L-His-l-ProNH(2); NP-647) was evaluated for its effects in in vitro (oxygen glucose deprivation (OGD)-, glutamate- and H(2)O(2)-induced injury in PC-12 cells) and in vivo (transient global ischemia) models of cerebral ischemic injury. PC-12 cells were subjected to oxygen and glucose deprivation for 6h. Exposure of NP-647 was given before and during OGD. In glutamate and H(2)O(2) induced injury, exposure of NP-647 was given 1, 6 and 24h prior to exposure of glutamate and H(2)O(2) exposure. NP-647, per se found to be non-toxic in 1-100μM concentrations. NP-647 showed protection against OGD at the 1 and 10μM. The concentration-dependent protection was observed in H(2)O(2)- and glutamate-induced cellular injury. In in vivo studies, NP-647 treatment showed protection of hippocampal (CA1) neuronal damage in transient global ischemia in mice and subsequent improvement in memory retention was observed using passive avoidance retention test. Moreover, administration of NP-647 resulted in decrease in inflammatory cytokines TNF-α and IL-6 as well as lipid peroxidation. These results suggest potential of NP-647 in the treatment of cerebral ischemia and its neuroprotective effect may be attributed to reduction of excitotoxicity, oxidative stress and inflammation.
Collapse
Affiliation(s)
- Satyendra Kumar Rajput
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, (Mohali), Punjab 160 062, India
| | | | | | | | | | | | | |
Collapse
|
5
|
Jaworska-Feil L, Jantas D, Leskiewicz M, Budziszewska B, Kubera M, Basta-Kaim A, Lipkowski AW, Lason W. Protective effects of TRH and its analogues against various cytotoxic agents in retinoic acid (RA)-differentiated human neuroblastoma SH-SY5Y cells. Neuropeptides 2010; 44:495-508. [PMID: 20869113 DOI: 10.1016/j.npep.2010.08.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 08/19/2010] [Accepted: 08/30/2010] [Indexed: 12/30/2022]
Abstract
TRH (thyroliberin) and its analogues were reported to possess neuroprotective effects in cellular and animal experimental models of acute and chronic neurodegenerative diseases. In the present study we evaluated effects of TRH and its three stable analogues, montirelin (CG-3703), RGH-2202 and Z-TRH (N-(carbobenzyloxy)-pGlutamyl-Histydyl-Proline) on the neuronally differentiated human neuroblastoma SH-SY5Y cell line, which is widely accepted for studying potential neuroprotectants. We found that TRH and all the tested analogues at concentrations 0.1-50 μM attenuated cell damage induced by MPP(+) (2 mM), 3-nitropropionate (10 mM), hydrogen peroxide (0.5 mM), homocysteine (250 μM) and beta-amyloid (20μM) in retinoic acid differentiated SH-SY5Y cells. Furthermore, we demonstrated that TRH and its analogues decreased the staurosporine (0.5 μM)-induced LDH release, caspase-3 activity and DNA fragmentation, which indicate the anti-apoptotic proprieties of these peptides. The neuroprotective effects of TRH (10 μM) and RGH-2202 (10 μM) on St-induced cell death was attenuated by inhibitors of PI3-K pathway (wortmannin and LY294002), but not MAPK/ERK1/2 (PD98059 and U0126). Moreover, TRH and its analogues at neuroprotective concentrations (1 and 10 μM) increased expression of Bcl-2 protein, as confirmed by Western blot analysis. All in all, these results extend data on neuroprotective properties of TRH and its analogues and provide evidence that mechanism of anti-apoptotic effects of these peptides in SH-SY5Y cell line involves induction of PI3K/Akt pathway and Bcl-2. Furthermore, the data obtained on human cell line with a dopaminergic phenotype suggest potential utility of TRH and its analogues in the treatment of some neurodegenerative diseases including Parkinson's disease.
Collapse
Affiliation(s)
- L Jaworska-Feil
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Cadet JL, McCoy MT, Cai NS, Krasnova IN, Ladenheim B, Beauvais G, Wilson N, Wood W, Becker KG, Hodges AB. Methamphetamine preconditioning alters midbrain transcriptional responses to methamphetamine-induced injury in the rat striatum. PLoS One 2009; 4:e7812. [PMID: 19915665 PMCID: PMC2771908 DOI: 10.1371/journal.pone.0007812] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 10/15/2009] [Indexed: 01/19/2023] Open
Abstract
Methamphetamine (METH) is an illicit drug which is neurotoxic to the mammalian brain. Numerous studies have revealed significant decreases in dopamine and serotonin levels in the brains of animals exposed to moderate-to-large METH doses given within short intervals of time. In contrast, repeated injections of small nontoxic doses of the drug followed by a challenge with toxic METH doses afford significant protection against monoamine depletion. The present study was undertaken to test the possibility that repeated injections of the drug might be accompanied by transcriptional changes involved in rendering the nigrostriatal dopaminergic system refractory to METH toxicity. Our results confirm that METH preconditioning can provide significant protection against METH-induced striatal dopamine depletion. In addition, the presence and absence of METH preconditioning were associated with substantial differences in the identity of the genes whose expression was affected by a toxic METH challenge. Quantitative PCR confirmed METH-induced changes in genes of interest and identified additional genes that were differentially impacted by the toxic METH challenge in the presence of METH preconditioning. These genes include small heat shock 27 kD 27 protein 2 (HspB2), thyrotropin-releasing hormone (TRH), brain derived neurotrophic factor (BDNF), c-fos, and some encoding antioxidant proteins including CuZn superoxide dismutase (CuZnSOD), glutathione peroxidase (GPx)-1, and heme oxygenase-1 (Hmox-1). These observations are consistent, in part, with the transcriptional alterations reported in models of lethal ischemic injuries which are preceded by ischemic or pharmacological preconditioning. Our findings suggest that multiple molecular pathways might work in tandem to protect the nigrostriatal dopaminergic pathway against the deleterious effects of the toxic psychostimulant. Further analysis of the molecular and cellular pathways regulated by these genes should help to provide some insight into the neuroadaptive potentials of the brain when repeatedly exposed to drugs of abuse.
Collapse
Affiliation(s)
- Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, DHHS/NIH/NIDA Intramural Research Program, Baltimore, MD, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Jantas D, Jaworska-Feil L, Lipkowski AW, Lason W. Effects of TRH and its analogues on primary cortical neuronal cell damage induced by various excitotoxic, necrotic and apoptotic agents. Neuropeptides 2009; 43:371-85. [PMID: 19666192 DOI: 10.1016/j.npep.2009.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 07/17/2009] [Accepted: 07/18/2009] [Indexed: 11/17/2022]
Abstract
The tripeptide thyrotropin-releasing hormone (TRH, pGlu-His-Pro-NH2) has been shown to possess neuroprotective activity in in vitro and in vivo models. Since its potential utility is limited by relatively rapid metabolism, metabolically stabilized analogues have been constructed. In the present study we investigated the influence of TRH and its three stable analogues: Montirelin (MON, CG-3703), RGH-2202 (L-6-keto-piperidine-2carbonyl-l-leucyl-l-prolinamide) and Z-TRH (N-carbobenzyloxy-pGlutamyl-Histydyl-Proline) in various models of mouse cortical neuronal cell injury. Twenty four hour pre-treatment with TRH and its analogues in low micromolar concentrations attenuated the neuronal cell death evoked by excitatory amino acids (EAAs: glutamate, NMDA, kainate, quisqualate) and hydrogen peroxide. All the peptides showed neuroprotective action on staurosporine (St)-evoked apoptotic neuronal cell death, but this effect was caspase-3 independent. Interestingly, in mixed neuronal-glial cell preparations only MON decreased St- and glutamate-evoked neurotoxicity. None of the peptides inhibited the doxorubicin- and lactacystin-induced neuronal cortical cell death, agents acting via activation of death receptor (FAS) or inhibition of proteasome function, respectively. Furthermore, we found that neither inhibitors of PI3-K (wortmannin, LY 294002) nor MAPK/ERK1/2 (PD 098059, U 0126) were able to inhibit neuroprotective properties of TRH and MON in St model of apoptosis. The protection mediated by TRH and MON it that model was also not connected with influence of peptides on the pro-apoptotic GSK-3beta and JNK protein kinase expression and activity. Further studies showed that calpains, calcium-activated proteases were induced by Glu, but not by St in cortical neurons. Moreover, the Glu-evoked increase in spectrin alpha II cleavage product induced by calpains was blocked by TRH. The obtained data showed that the potency of TRH and its analogues in inhibiting EAAs- and H(2)O(2)-induced neuronal cell death from the highest to lowest activity was: MON>TRH>Z-TRH>RHG. Interestingly, all peptides were active against St-induced apoptosis, however, on concentration basis MON was far more potent than the other peptides. None of the peptides inhibited Dox- and LC-evoked apoptotic cell death. Additionally, the data exclude potential role of pro-survival (PI3-K/Akt and MAPK/ERK1/2) and pro-apoptotic (GSK-3beta and JNK) pathways in neuroprotective effects of TRH and its analogues on St-induced neuronal apoptosis. Moreover, the results point to involvement of the inhibition of calpains in the TRH neuroprotective effect in Glu model of neuronal cell death.
Collapse
Affiliation(s)
- D Jantas
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, PL 31-343 Krakow, Poland.
| | | | | | | |
Collapse
|
8
|
Thyrotropin-releasing hormone d,l polylactide nanoparticles (TRH-NPs) protect against glutamate toxicity in vitro and kindling development in vivo. Brain Res 2009; 1303:151-60. [PMID: 19766611 DOI: 10.1016/j.brainres.2009.09.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/03/2009] [Accepted: 09/11/2009] [Indexed: 11/22/2022]
Abstract
Thyrotropin-releasing hormone (TRH) is reported to have anticonvulsant effects in animal seizure models and certain intractable epileptic patients. However, its duration of action is limited by rapid tissue metabolism and the blood brain barrier. Direct nose-brain delivery of neuropeptides in sustained-release biodegradable nanoparticles (NPs) is a promising mode of therapy for enhancing CNS bioavailability. Bioactivity/neuroprotection of d,l polylactide nanoparticles containing TRH was assessed against glutamate toxicity in cultured rat fetal hippocampal neurons. Subsequently, we utilized the kindling model of temporal lobe epilepsy to determine if intranasal administration of nanoparticles containing TRH (TRH-NPs) could inhibit kindling development. Animals received daily treatments of either blank (control) or TRH-NPs for 7 days before initiation of kindling. On day 8 and each day thereafter until either fully kindled or until day 20, the animals received daily treatments before receiving a kindling stimulus 3 h later. Afterdischarge duration (ADD) was assessed via electroencephalographs recorded from electrodes in the basolateral amygdalae and behavioral seizure stereotypy was simultaneously recorded digitally. Intranasal application of TRH-NPs resulted in a significant reduction in seizure ADD as kindling progressed, while the number of stimulations required to reach stage V seizures and to become permanently kindled was significantly greater in TRH-NP-treated subjects. Additionally, delay to clonus was significantly prolonged while clonus duration was reduced indicating a less severe seizure in TRH-NP-treated subjects. Our results provide proof of principle that intranasal delivery of sustained-release TRH-NPs may be neuroprotective and can be utilized to suppress seizures and perhaps epileptogenesis.
Collapse
|
9
|
Guan J, Mathai S, Harris P, Wen JY, Zhang R, Brimble M, Gluckman P. Peripheral administration of a novel diketopiperazine, NNZ 2591, prevents brain injury and improves somatosensory-motor function following hypoxia-ischemia in adult rats. Neuropharmacology 2007; 53:749-62. [PMID: 17904590 DOI: 10.1016/j.neuropharm.2007.08.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 08/03/2007] [Accepted: 08/06/2007] [Indexed: 11/29/2022]
Abstract
The current study describes the neuroprotective effects of an endogenous diketopiperazine, cyclo-glycyl-proline (cyclic GP), in rats with hypoxic-ischemic brain injury and the pre-clinical development of an analogue, cyclo-L-glycyl-L-2-allylproline (NNZ 2591), modified for improved bioavailability. The compounds were given either intracerebroventricularly or subcutaneously 2h after hypoxia-ischemia. Histology, immunohistochemistry and behavior were used to evaluate treatment effects. The central uptake of NNZ 2591 was also examined in normal and hypoxic-ischemic injured rats by HPLC-mass spectrometry. Central administration of cyclic GP or NNZ 2591 reduced the extent of brain damage in the lateral cortex, the hippocampus and the striatum (p<0.001), with NNZ 2591 being more potent. NNZ 2591 was stable in the plasma and crossed the blood-brain barrier independent of hypoxic-ischemic injury. The level of NNZ 2591 in the CSF was maintained for 2 h after a single subcutaneous dose, and modest neuroprotection was seen after a bolus subcutaneous administration (overall p<0.001). Treatment with NNZ 2591 for 5 d subcutaneously improved somatosensory-motor function (p<0.05) and long-term histological outcome (overall p<0.0001). NNZ 2591 treatment not only reduced both caspase-3 mediated apoptosis and microglial activation but also enhanced astrocytic reactivity, which may mediate its protective effect. The pharmacokinetic profile and potent long-term protective effects of NNZ 2591 suggests its utility for the treatment of ischemic brain injury and other neurological conditions requiring chronic intervention.
Collapse
Affiliation(s)
- J Guan
- The Liggins Institute, University of Auckland, Private Bag 92019, Auckland, New Zealand.
| | | | | | | | | | | | | |
Collapse
|
10
|
Tanabe M, Tokuda Y, Takasu K, Ono K, Honda M, Ono H. The synthetic TRH analogue taltirelin exerts modality-specific antinociceptive effects via distinct descending monoaminergic systems. Br J Pharmacol 2007; 150:403-14. [PMID: 17220907 PMCID: PMC2189720 DOI: 10.1038/sj.bjp.0707125] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE Exogenously administered thyrotropin-releasing hormone (TRH) is known to exert potent but short-acting centrally-mediated antinociceptive effects. We sought to investigate the mechanisms underlying these effects using the synthetic TRH analogue taltirelin, focusing on the descending monoaminergic systems in mice. EXPERIMENTAL APPROACH The mice received systemic or local injections of taltirelin combined with either central noradrenaline (NA) or 5-hydroxytryptamine (5-HT) depletion by 6-hydroxydopamine (6-OHDA) or DL-p-chlorophenylalanine (PCPA), respectively, or blockade of their receptors. The degree of antinociception was determined using the tail flick and tail pressure tests. KEY RESULTS Subcutaneously (s.c.) administered taltirelin exhibited dose-dependent antinociceptive effects in the tail flick and tail pressure tests. These effects appeared to be primarily supraspinally mediated, since intracerebroventricularly (i.c.v.) but not intrathecally (i.t.) injected taltirelin generated similar effects. Depletion of central NA abolished only the analgesic effect of taltirelin (s.c. and i.c.v.) on mechanical nociception. By contrast, depletion of central 5-HT abolished only its analgesic effect on thermal nociception. Intraperitoneal (i.p.) and i.t. injection of the alpha2-adrenoceptor antagonist yohimbine respectively reduced the analgesic effect of taltirelin (s.c. and i.c.v.) on mechanical nociception. By contrast, the 5-HT1A receptor antagonist WAY-100635 (i.p. and i.t.) reduced the effect of taltirelin (s.c. and i.c.v.) on thermal nociception. Neither the 5-HT2 receptor antagonist ketanserin nor the opioid receptor antagonist naloxone altered the antinociceptive effect of taltirelin. CONCLUSIONS AND IMPLICATIONS These findings suggest that taltirelin activates the descending noradrenergic and serotonergic pain inhibitory systems, respectively, to exert its analgesic effects on mechanical and thermal nociception.
Collapse
Affiliation(s)
- M Tanabe
- Laboratory of CNS Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan.
| | | | | | | | | | | |
Collapse
|
11
|
Veronesi MC, Yard M, Jackson J, Lahiri DK, Kubek MJ. An analog of thyrotropin-releasing hormone (TRH) is neuroprotective against glutamate-induced toxicity in fetal rat hippocampal neurons in vitro. Brain Res 2007; 1128:79-85. [PMID: 17125753 PMCID: PMC2645863 DOI: 10.1016/j.brainres.2006.10.047] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 10/23/2006] [Accepted: 10/24/2006] [Indexed: 12/24/2022]
Abstract
TRH has been found to be efficacious in treating certain neurodegenerative disorders such as epilepsy, Alzheimer's disease, neurotrauma and depression, however, its mechanism of action is poorly understood. Since glutamate (Glu) toxicity has been implicated in these disorders, we utilized primary enriched cultures of rat fetal (E 17) hippocampal neurons to test the hypothesis that an analog of TRH, 3-Methyl-Histidine TRH (3Me-H TRH), given concurrently with Glu would protect such neurons against cell damage and cell death. Cell viability was assessed via Trypan Blue exclusion cell counts, and neuronal damage was determined by assaying lactic acid dehydrogenase (LDH) released in the conditioned media. Fetal hippocampal neurons were cultured in neurobasal media for 7 days. On day 7, neurons (10(6)/well) were treated with: control media, 10 microM 3Me-H TRH, 500 microM Glu or 500 microM Glu with either 10, 1, 0.1, 0.01 or 0.001 microM 3Me-H TRH. Both media and neurons were harvested 16 h after treatment. Prolonged exposure to 10 microM 3Me-H TRH was not toxic to the cells, whereas neurons exposed to 500 microM Glu resulted in maximal cell death. Notably, 10, 1 and 0.1 microM 3Me-H TRH, when co-treated with 500 microM Glu, protected fetal neurons against cell death in a concentration-dependent manner. These results provide support for an important neuroprotective effect of TRH/analogs against glutamate toxicity in primary hippocampal neuronal culture and implicate a potentially beneficial role of TRH/analogs in neurodegenerative diseases.
Collapse
Affiliation(s)
- Michael C. Veronesi
- Program in Medical Neurobiology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Michael Yard
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202
- Program in Medical Neurobiology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - James Jackson
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Debomoy K. Lahiri
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202
- Program in Medical Neurobiology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Michael J. Kubek
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202
- Program in Medical Neurobiology, Indiana University School of Medicine, Indianapolis, IN 46202
| |
Collapse
|
12
|
Luo L, Yano N, Luo JZQ. The molecular mechanism of EGF receptor activation in pancreatic beta-cells by thyrotropin-releasing hormone. Am J Physiol Endocrinol Metab 2006; 290:E889-99. [PMID: 16603724 DOI: 10.1152/ajpendo.00466.2005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Thyrotropin-releasing hormone (TRH) and its receptor subtype TRH receptor-1 (TRHR1) are found in pancreatic beta-cells, and it has been shown that TRH might have potential for autocrine/paracrine regulation through the TRHR1 receptor. In this paper, TRHR1 is studied to find whether it can initiate multiple signal transduction pathways to activate the epidermal growth factor (EGF) receptor in pancreatic beta-cells. By initiating TRHR1 G protein-coupled receptor (GPCR) and dissociated alphabetagamma-complex, TRH (200 nM) activates tyrosine residues at Tyr845 (a known target for Src) and Tyr1068 in the EGF receptor complex of an immortalized mouse beta-cell line, betaTC-6. Through manipulating the activation of Src, PKC, and heparin-binding EGF-like growth factor (HB-EGF), with corresponding individual inhibitors and activators, multiple signal transduction pathways linking TRH to EGF receptors in betaTC-6 cell line have been revealed. The pathways include the activation of Src kinase and the release of HB-EGF as a consequence of matrix metalloproteinase (MMP)-3 activation. Alternatively, TRH inhibited PKC activity by reducing the EGF receptor serine/threonine phosphorylation, thereby enhancing tyrosine phosphorylation. TRH receptor activation of Src may have a central role in mediating the effects of TRH on the EGF receptor. The activation of the EGF receptor by TRH in multiple circumstances may have important implications for pancreatic beta-cell biology.
Collapse
Affiliation(s)
- LuGuang Luo
- The Center for Stem Cell Biology, Department of Research, Roger Williams Hospital, 825 Chalkstone Ave., Providence, RI 02908, USA
| | | | | |
Collapse
|
13
|
Hunsberger JG, Bennett AH, Selvanayagam E, Duman RS, Newton SS. Gene profiling the response to kainic acid induced seizures. ACTA ACUST UNITED AC 2005; 141:95-112. [PMID: 16165245 DOI: 10.1016/j.molbrainres.2005.08.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Revised: 07/07/2005] [Accepted: 08/07/2005] [Indexed: 01/19/2023]
Abstract
Kainic acid activates non-N-methyl-d-aspartate (NMDA) glutamate receptors where it increases synaptic activity resulting in seizures, neurodegeneration, and remodeling. We performed microarray analysis on rat hippocampal tissue following kainic acid treatment in order to study the signaling mechanisms underlying these diverse processes in an attempt to increase our current understanding of mechanisms contributing to such fundamental processes as neuronal protection and neuronal plasticity. The kainic acid-treated rats used in our array experiments demonstrated severe seizure behavior that was also accompanied by neuronal degeneration which is suggested by fluoro-jade B staining and anti-caspase-3 immunohistochemistry. The gene profile revealed 36 novel kainic acid regulated genes along with additional genes previously reported. The functional roles of these novel genes are discussed. These genes mainly have roles in transcription and to a lesser extent have roles in cell death, extracellular matrix remodeling, cell cycle progression, neuroprotection, angiogenesis, and synaptic signaling. Gene regulation was confirmed via quantitative real time polymerase chain reaction and in situ hybridization.
Collapse
Affiliation(s)
- Joshua G Hunsberger
- Yale University School of Medicine, 34 Park Street, CMHC, New Haven, CT 06520, USA
| | | | | | | | | |
Collapse
|
14
|
Eugene Pekary A, Faull KF, Paulson M, Lloyd RL, Sattin A. TRH-like antidepressant peptide, pyroglutamyltyroslyprolineamide, occurs in rat brain. JOURNAL OF MASS SPECTROMETRY : JMS 2005; 40:1232-6. [PMID: 16124040 DOI: 10.1002/jms.904] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We have previously reported the occurrence of pGlu-Glu-Pro-NH(2)(Glu-TRH, EEP), Val-TRH, Tyr-TRH, Leu-TRH, Phe-TRH, and Trp-TRH in rat brain using a combination of HPLC and radioimmunoassays with antibodies that cross-react with the general structure pGlu-X-Pro-NH(2) where 'X' maybe any amino acid residue (Peptides 2004; 25 : 647). This new family of TRH-like peptides, along with TRH (pGlu-His-Pro-NH(2)), has neuroprotective, anticonvulsant, antidepressant, euphoric, anti-amnesic, and analeptic effects. We now report that a combination of affinity chromatography using a rabbit antibody specific for Tyr-TRH and Phe-TRH, along with HPLC and tandem mass spectrometry operating in the multiple reaction monitoring (MRM) mode, provide conclusive evidence for the presence of Tyr-TRH in rat brain. Furthermore, synthetic Tyr-TRH is active in the Porsolt Swim Test suggesting that it is a fourth member of this family of in vivo neuroregulatory agents that have psychopharmacotherapeutic properties.
Collapse
Affiliation(s)
- A Eugene Pekary
- Research Service, VA Greater Los Angeles Healthcare System and Department of Medicine, University of California, Los Angeles, CA 90073, USA.
| | | | | | | | | |
Collapse
|
15
|
Nie Y, Schoepp DD, Klaunig JE, Yard M, Lahiri DK, Kubek MJ. Thyrotropin-releasing hormone (protirelin) inhibits potassium-stimulated glutamate and aspartate release from hippocampal slices in vitro. Brain Res 2005; 1054:45-54. [PMID: 16055093 DOI: 10.1016/j.brainres.2005.06.077] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 06/17/2005] [Accepted: 06/25/2005] [Indexed: 10/25/2022]
Abstract
Excess excitatory amino acid release is involved in pathways associated with seizures and neurodegeneration. Thyrotropin-releasing hormone (TRH; protirelin), a brain-derived tripeptide, has shown efficacy in the treatment of such disorders, yet its mechanism of neuroprotection is poorly understood. Using superfused hippocampal slices, we tested the hypothesis that TRH could inhibit evoked glutamate/aspartate release in vitro. Rat hippocampal slices were first equilibrated in oxygenated Krebs buffer (KRB) (120 min) then superfused for 10 min with KRB (control), or KRB containing 0.1, 1, or 10 microM TRH respectively, prior to and during 5 min depolarization with high potassium KRB (50 mM [K(+)] +/- TRH). Fractions (1 min) were collected during the 5 min stimulation and for an additional 10 min thereafter and analyzed for glutamate and aspartate by HPLC. TRH had no effect on baseline glutamate/aspartate release, while all three TRH doses significantly (P < 0.05) inhibited peak 50 mM [K(+)]-stimulated glutamate/aspartate release, and glutamate remained below control (P < 0.05) at 15 min post stimulation. A 5 min pulse of TRH (10 microM) had no affect on basal glutamate/aspartate release, whereas the TRH pre-pulsed slices failed to release glutamate/aspartate by [K(+)]-stimulation given 15 min later. These results are the first to show a potent and prolonged inhibitory effect of TRH on evoked glutamate/aspartate release in vitro. These initial studies suggest that exogenous and/or endogenous TRH may function, in part, to modulate excess glutamate release in specific CNS loci. Additional studies are in progress to fully understand the mechanism of this potent effect of TRH and its implication in various CNS disorders.
Collapse
Affiliation(s)
- Y Nie
- Department of Anatomy and Cell Biology, MS 5035, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | | | | | | | | | | |
Collapse
|
16
|
Valdivia A, Irazusta J, Fernández D, Múgica J, Ochoa C, Casis L. Pyroglutamyl peptidase I and prolyl endopeptidase in human semen: increased activity in necrozoospermia. ACTA ACUST UNITED AC 2004; 122:79-84. [PMID: 15380924 DOI: 10.1016/j.regpep.2004.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2004] [Revised: 05/21/2004] [Accepted: 05/21/2004] [Indexed: 11/16/2022]
Abstract
Thyrotropin-releasing hormone (TRH) and its analogues have been reported to have important functions in human semen. In the present paper, we have characterized the activity of the TRH-degrading enzymes pyroglutamyl peptidase I and prolyl endopeptidase in the fluid and prostasomes of human semen and in subcellular fractions of the corresponding sperm. Enzymatic activities were measured fluorimetrically using beta-naphthylamine derivatives as substrate. Activity associated with both enzymes was detected in seminal fluid and in the prostasome fraction, as well as in soluble and particulate sperm subcellular fractions. Pyroglutamyl-peptidase I activity presented highest levels in the particulate sperm fraction, whereas the activity of prolyl endopeptidase was maximal in the soluble sperm fraction. In addition, we compared the activity of both enzymes in different seminal fractions in normozoospermic, fertile men and in subfertile patients with different abnormalities revealed by spermiogram analysis (astenozoospermia, necrozoospermia and teratozoospermia). The activities of pyroglutamyl peptidase I and prolyl endopeptidase in necrozoospermia were found to be higher in the corresponding soluble and particulate sperm fractions, respectively, with respect to those measured in normozoospermic semen. The results of the present study indicate that these enzymes may participate in regulating the levels of seminal TRH analogues and in mediating sperm death associated with necrozoospermia.
Collapse
Affiliation(s)
- Asier Valdivia
- Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, P.O. Box 699 Bilbao, Bizkaia, Spain.
| | | | | | | | | | | |
Collapse
|
17
|
Lewerenz J, Letz J, Methner A. Activation of stimulatory heterotrimeric G proteins increases glutathione and protects neuronal cells against oxidative stress. J Neurochem 2003; 87:522-31. [PMID: 14511129 DOI: 10.1046/j.1471-4159.2003.02019.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Oxidative glutamate toxicity in the neuronal cell line HT22 is a model for cell death by oxidative stress, where an excess of extracellular glutamate inhibits import of cystine, a building block of the antioxidant glutathione. The subsequent decrease in glutathione then leads to the accumulation of reactive oxygen species (ROS) and programmed cell death. We used pharmacological compounds known to interact with heterotrimeric G-protein signalling and studied their effects on cell survival, morphology, and intracellular events that ultimately lead to cell death. Cholera toxin and phorbol esters were most effective and prevented cell death through independent pathways. Treating HT22 cells with cholera toxin attenuated the glutamate-induced accumulation of ROS and calcium influx. This was, at least in part, caused by an increase in glutathione due to improved uptake of cystine mediated by the induction of the glutamate/cystine-antiporter subunit xCT or, additionally, by the up-regulation of the antiapoptotic protein Bcl-2. Gs activation also protected HT22 cells from hydrogen peroxide or inhibition of glutathione synthesis by buthionine sulfoximine, and immature cortical neurones from oxidative glutamate toxicity. Thus, this pathway might be more generally implicated in protection from neuronal death by oxidative stress.
Collapse
Affiliation(s)
- Jan Lewerenz
- Research Group Protective Signalling, Zentrum für Molekulare Neurobiologie and Department of Neurology, University Hospital Hamburg, Hamburg, Germany
| | | | | |
Collapse
|
18
|
Urayama A, Yamada S, Kimura R, Zhang J, Watanabe Y. Neuroprotective effect and brain receptor binding of taltirelin, a novel thyrotropin-releasing hormone (TRH) analogue, in transient forebrain ischemia of C57BL/6J mice. Life Sci 2002; 72:601-7. [PMID: 12467901 DOI: 10.1016/s0024-3205(02)02268-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Thyrotropin-releasing hormone (TRH) and some of its stable analogues have been shown to improve neurologic dysfunctions such as brain trauma in both animals and humans. Our previous study revealed that taltirelin, a novel orally active TRH analogue, binds to rat brain TRH receptors in vivo. The present study was undertaken to investigate whether taltirelin has neuroprotective effects in transient brain ischemia of C57BL/6J mice induced by bilateral carotid artery occlusion (2VO). Neuronal cell density in the hippocampal CA1 region of C57BL/6J mice was significantly (39.9%) decreased 1 week after 2VO-reperfusion, compared to the case of the sham group, and this reduction of hippocampal neuronal density was significantly suppressed by an intravenous (i.v.) injection of taltirelin (0.3 mg/kg). The i.v. injection of taltirelin at this dosage produced a significant increase in the dissociation constant (Kd) of specific [3H]MeTRH binding in sham and 2VO-reperfusion groups (33.6 and 51.4%, respectively) compared with the vehicle-treated group. These results indicate that the intravenously injected taltirelin bound to TRH receptors in the ischemic brain. There was little difference in the brain-to-plasma concentration ratio (Kp) of [14C]sucrose between the sham and 2VO groups of C57BL/6J mice, indicating that the tight junction of the blood-brain barrier may be intact in the ischemic brain. In conclusion, the study has shown that taltirelin may have a significant neuroprotective effect on the ischemic brain.
Collapse
Affiliation(s)
- Akihiko Urayama
- Department of Biopharmacy, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka, Shizuoka,422-8526, Japan
| | | | | | | | | |
Collapse
|
19
|
Koenig ML, Sgarlat CM, Yourick DL, Long JB, Meyerhoff JL. In vitro neuroprotection against glutamate-induced toxicity by pGlu-Glu-Pro-NH(2) (EEP). Peptides 2001; 22:2091-7. [PMID: 11786195 DOI: 10.1016/s0196-9781(01)00544-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
EEP is a tripeptide structurally similar to thyrotropin releasing hormone (TRH) and, like TRH, it is found in the mammalian brain. TRH has been found to increase in brain regions after seizures and to be neuroprotective. EEP has also been shown to increase in brain regions following seizure activity. We therefore sought to determine whether the similarities between these two peptides might be extended to include neuroprotection. Both TRH and EEP were found to be neuroprotective in vitro against an excitotoxic insult. Interestingly, the two tripeptides appeared to have different mechanisms of action. Even though EEP was as much as four times more neuroprotective than TRH, its ability to reduce glutamate-stimulated increases in intraneuronal Ca(2+) was about half that of TRH.
Collapse
Affiliation(s)
- M L Koenig
- Department of Neuroendocrinology and Neurochemistry, Division of Neurosciences, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500, USA.
| | | | | | | | | |
Collapse
|
20
|
Jaworska-Feil L, Kajta M, Budziszewska B, Leśkiewicz M, Lasoń W. Protective effects of TRH and its stable analogue, RGH-2202, on kainate-induced seizures and neurotoxicity in rodents. Epilepsy Res 2001; 43:67-73. [PMID: 11137388 DOI: 10.1016/s0920-1211(00)00178-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Thyrotropin-releasing hormone (TRH) has been postulated to be involved in the regulation of seizures and neural degeneration. We examined the effects of TRH and its stable analogue, RGH-2202, on the kainate-induced seizures and excitotoxicity in mice - a model of a drug-resistant temporal lobe epilepsy. We found that TRH (2.0 and 5.0 mg/kg) and RGH-2202 (2.5 and 5 mg/kg) elevated the ED(50) for kainate-induced convulsions and tended to decrease mortality. A histological analysis showed that kainate caused a neuronal loss of CA(1) and CA(3) hippocampal fields. TRH (10, 20 and 50 mg/kg) and RGH-2202 (2.5, 7.5 and 10.0 mg/kg) markedly reduced the excitotoxic effect of kainate. Further studies showed that TRH (1-100 microM) and RGH-2202 (100 microM) significantly attenuated the kainate (150 microM)-induced lactate dehydrogenase release in a primary cortical cell culture from rat embryos. In conclusion, the present study showed that TRH and RGH-2202 attenuated the kainate-induced seizures and inhibited the kainate-evoked neurotoxicity in vivo and in vitro. These results support the hypothesis of a potential utility of TRH and its analogues in the treatment of seizures and some neurodegenerative diseases.
Collapse
Affiliation(s)
- L Jaworska-Feil
- Department of Endocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna St., 31-343, Kraków, Poland
| | | | | | | | | |
Collapse
|