1
|
de Sousa EB, Heymbeeck JAA, Feitosa LM, Xavier AGO, Dos Santos Almeida CE, da Cruz EV, Dos Santos Campos K, do Socorro Dos Santos Rodrigues L, de Freitas LM, da Silva Brito MG, do Carmo Silva RX, de Paula Torres SL, Ikeda SR, de Nazaré Dos Santos Silva S, Rocha SP, do Nascimento WL, da Silva Moraes ER, Herculano AM, Maximino C, Pereira A, Lima-Maximino M. Activation of NOS-cGMP pathways promotes stress-induced sensitization of behavioral responses in zebrafish. Pharmacol Biochem Behav 2024:173816. [PMID: 38971472 DOI: 10.1016/j.pbb.2024.173816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 06/20/2024] [Accepted: 07/03/2024] [Indexed: 07/08/2024]
Abstract
Nitric oxide (NO) is a molecule involved in plasticity across levels and systems. The role of NOergic pathways in stress-induced sensitization (SIS) of behavioral responses, in which a particular stressor triggers a state of hyper-responsiveness to other stressors after an incubation period, was assessed in adult zebrafish. In this model, adult zebrafish acutely exposed to a fear-inducing conspecific alarm substance (CAS) and left undisturbed for an incubation period show increased anxiety-like behavior 24 h after exposure. CAS increased forebrain glutamate immediately after stress and 30 min after stress, an effect that was accompanied by increased nitrite levels immediately after stress, 30 min after stress, 90 min after stress, and 24 h after stress. CAS also increased nitrite levels in the head kidney, where cortisol is produced in zebrafish. CAS-elicited nitrite responses in the forebrain 90 min (but not 30 min) after stress were prevented by a NOS-2 blocker. Blocking NOS-1 30 min after stress prevents SIS; blocking NOS-2 90 min after stress also prevents stress-induced sensitization, as does blocking calcium-activated potassium channels in this latter time window. Stress-induced sensitization is also prevented by blocking guanylate cyclase activation in both time windows, and cGMP-dependent channel activation in the second time window. These results suggest that different NO-related pathways converge at different time windows of the incubation period to induce stress-induced sensitization.
Collapse
Affiliation(s)
- Eveline Bezerra de Sousa
- Laboratório de Bacteriologia e Neuropatologia, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil; Programa de Pós-Graduação em Neurociências e Biologia Celular, Instituto de Estudos em Saúde e Biológicas, Universidade Federal do Pará (UFPA), Belém, PA, Brazil
| | - João Alphonse Apóstolo Heymbeeck
- Laboratório de Neurofarmacologia e Biofísica, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil; Programa de Pós-Graduação em Neurociências e Comportamento, Núcleo de Teoria e Pesquisa do Comportamento, Universidade Federal do Pará (UFPA), Belém, PA, Brazil
| | - Leonardo Miranda Feitosa
- Laboratório de Neurofarmacologia e Biofísica, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil; Programa de Pós-Graduação em Neurociências e Comportamento, Núcleo de Teoria e Pesquisa do Comportamento, Universidade Federal do Pará (UFPA), Belém, PA, Brazil
| | | | | | - Eliane Veiga da Cruz
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | - Kimberly Dos Santos Campos
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | | | - Larissa Mota de Freitas
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | | | - Rhayra Xavier do Carmo Silva
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | - Sara Letícia de Paula Torres
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | - Saulo Rivera Ikeda
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | | | - Sueslene Prado Rocha
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | - Wilker Leite do Nascimento
- Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| | | | - Anderson Manoel Herculano
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará (UFPA), Belém, PA, Brazil
| | - Caio Maximino
- Laboratório de Neurociências e Comportamento "Frederico Guilherme Graeff", Instituto de Estudos em Saúde e Biológicas, Universidade Federal do Sul e Sudeste do Pará (Unifesspa), Marabá, PA, Brazil.
| | - Antonio Pereira
- Laboratório de Processamento de Sinais, Instituto de Tecnologia, Universidade Federal do Pará (UFPA), Belém, PA, Brazil
| | - Monica Lima-Maximino
- Laboratório de Neurofarmacologia e Biofísica, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil; Departamento de Morfologia e Ciências Fisiológicas, Universidade do Estado do Pará, Campus VIII, Marabá, PA, Brazil
| |
Collapse
|
2
|
Tibbs GR, Uprety R, Warren JD, Beyer NP, Joyce RL, Ferrer MA, Mellado W, Wong VSC, Goldberg DC, Cohen MW, Costa CJ, Li Z, Zhang G, Dephoure NE, Barman DN, Sun D, Ingólfsson HI, Sauve AA, Willis DE, Goldstein PA. An anchor-tether 'hindered' HCN1 inhibitor is antihyperalgesic in a rat spared nerve injury neuropathic pain model. Br J Anaesth 2023; 131:745-763. [PMID: 37567808 PMCID: PMC10541997 DOI: 10.1016/j.bja.2023.06.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/20/2023] [Accepted: 06/29/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND Neuropathic pain impairs quality of life, is widely prevalent, and incurs significant costs. Current pharmacological therapies have poor/no efficacy and significant adverse effects; safe and effective alternatives are needed. Hyperpolarisation-activated cyclic nucleotide-regulated (HCN) channels are causally implicated in some forms of peripherally mediated neuropathic pain. Whilst 2,6-substituted phenols, such as 2,6-di-tert-butylphenol (26DTB-P), selectively inhibit HCN1 gating and are antihyperalgesic, the development of therapeutically tolerable, HCN-selective antihyperalgesics based on their inverse agonist activity requires that such drugs spare the cardiac isoforms and do not cross the blood-brain barrier. METHODS In silico molecular dynamics simulation, in vitro electrophysiology, and in vivo rat spared nerve injury methods were used to test whether 'hindered' variants of 26DTB-P (wherein a hydrophilic 'anchor' is attached in the para-position of 26DTB-P via an acyl chain 'tether') had the desired properties. RESULTS Molecular dynamics simulation showed that membrane penetration of hindered 26DTB-Ps is controlled by a tethered diol anchor without elimination of head group rotational freedom. In vitro and in vivo analysis showed that BP4L-18:1:1, a variant wherein a diol anchor is attached to 26DTB-P via an 18-carbon tether, is an HCN1 inverse agonist and an orally available antihyperalgesic. With a CNS multiparameter optimisation score of 2.25, a >100-fold lower drug load in the brain vs blood, and an absence of adverse cardiovascular or CNS effects, BP4L-18:1:1 was shown to be poorly CNS penetrant and cardiac sparing. CONCLUSIONS These findings provide a proof-of-concept demonstration that anchor-tethered drugs are a new chemotype for treatment of disorders involving membrane targets.
Collapse
Affiliation(s)
- Gareth R Tibbs
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Rajendra Uprety
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - J David Warren
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Nicole P Beyer
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Rebecca L Joyce
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Matthew A Ferrer
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | | | | | | | | | | | - Zhucui Li
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Guoan Zhang
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Noah E Dephoure
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Dipti N Barman
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Delin Sun
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | | | - Anthony A Sauve
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Dianna E Willis
- Burke Neurological Institute, White Plains, NY, USA; Feil Family Brain & Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
| | - Peter A Goldstein
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA; Feil Family Brain & Mind Research Institute, Weill Cornell Medicine, New York, NY, USA; Department of Medicine, Weill Cornell Medicine, New York, NY, USA.
| |
Collapse
|
3
|
Zhao K, Li Y, Yang X, Zhou L. The Impact of Altered HCN1 Expression on Brain Function and Its Relationship with Epileptogenesis. Curr Neuropharmacol 2023; 21:2070-2078. [PMID: 37366350 PMCID: PMC10556362 DOI: 10.2174/1570159x21666230214110333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/13/2022] [Accepted: 12/06/2022] [Indexed: 03/08/2023] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated cation channel 1 (HCN1) is predominantly expressed in neurons from the neocortex and hippocampus, two important regions related to epilepsy. Both animal models for epilepsy and epileptic patients show decreased HCN1 expression and HCN1-mediated Ih current. It has been shown in neuroelectrophysiological experiments that a decreased Ih current can increase neuronal excitability. However, some studies have shown that blocking the Ih current in vivo can exert antiepileptic effects. This paradox raises an important question regarding the causal relationship between HCN1 alteration and epileptogenesis, which to date has not been elucidated. In this review, we summarize the literature related to HCN1 and epilepsy, aiming to find a possible explanation for this paradox, and explore the correlation between HCN1 and the mechanism of epileptogenesis. We analyze the alterations in the expression and distribution of HCN1 and the corresponding impact on brain function in epilepsy. In addition, we also discuss the effect of blocking Ih on epilepsy symptoms. Addressing these issues will help to inspire new strategies to explore the relationship between HCN1 and epileptogenesis, and ultimately promote the development of new targets for epilepsy therapy.
Collapse
Affiliation(s)
- Ke Zhao
- Department of Neurology, The Seventh Affliated Hospital of Sun Yet-sen University, No. 628, Zhenyuan Road, Xinhu Street, Guangming District, Shenzhen, China
| | - Yinchao Li
- Department of Neurology, The Seventh Affliated Hospital of Sun Yet-sen University, No. 628, Zhenyuan Road, Xinhu Street, Guangming District, Shenzhen, China
| | - Xiaofeng Yang
- Guangzhou Laboratory, Guangzhou, No. 9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, Guangdong Province, China
| | - Liemin Zhou
- Department of Neurology, The Seventh Affliated Hospital of Sun Yet-sen University, No. 628, Zhenyuan Road, Xinhu Street, Guangming District, Shenzhen, China
| |
Collapse
|
4
|
Kessi M, Peng J, Duan H, He H, Chen B, Xiong J, Wang Y, Yang L, Wang G, Kiprotich K, Bamgbade OA, He F, Yin F. The Contribution of HCN Channelopathies in Different Epileptic Syndromes, Mechanisms, Modulators, and Potential Treatment Targets: A Systematic Review. Front Mol Neurosci 2022; 15:807202. [PMID: 35663267 PMCID: PMC9161305 DOI: 10.3389/fnmol.2022.807202] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/06/2022] [Indexed: 12/04/2022] Open
Abstract
Background Hyperpolarization-activated cyclic nucleotide-gated (HCN) current reduces dendritic summation, suppresses dendritic calcium spikes, and enables inhibitory GABA-mediated postsynaptic potentials, thereby suppressing epilepsy. However, it is unclear whether increased HCN current can produce epilepsy. We hypothesized that gain-of-function (GOF) and loss-of-function (LOF) variants of HCN channel genes may cause epilepsy. Objectives This systematic review aims to summarize the role of HCN channelopathies in epilepsy, update genetic findings in patients, create genotype–phenotype correlations, and discuss animal models, GOF and LOF mechanisms, and potential treatment targets. Methods The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, for all years until August 2021. Results We identified pathogenic variants of HCN1 (n = 24), HCN2 (n = 8), HCN3 (n = 2), and HCN4 (n = 6) that were associated with epilepsy in 74 cases (43 HCN1, 20 HCN2, 2 HCN3, and 9 HCN4). Epilepsy was associated with GOF and LOF variants, and the mechanisms were indeterminate. Less than half of the cases became seizure-free and some developed drug-resistant epilepsy. Of the 74 cases, 12 (16.2%) died, comprising HCN1 (n = 4), HCN2 (n = 2), HCN3 (n = 2), and HCN4 (n = 4). Of the deceased cases, 10 (83%) had a sudden unexpected death in epilepsy (SUDEP) and 2 (16.7%) due to cardiopulmonary failure. SUDEP affected more adults (n = 10) than children (n = 2). HCN1 variants p.M234R, p.C329S, p.V414M, p.M153I, and p.M305L, as well as HCN2 variants p.S632W and delPPP (p.719–721), were associated with different phenotypes. HCN1 p.L157V and HCN4 p.R550C were associated with genetic generalized epilepsy. There are several HCN animal models, pharmacological targets, and modulators, but precise drugs have not been developed. Currently, there are no HCN channel openers. Conclusion We recommend clinicians to include HCN genes in epilepsy gene panels. Researchers should explore the possible underlying mechanisms for GOF and LOF variants by identifying the specific neuronal subtypes and neuroanatomical locations of each identified pathogenic variant. Researchers should identify specific HCN channel openers and blockers with high binding affinity. Such information will give clarity to the involvement of HCN channelopathies in epilepsy and provide the opportunity to develop targeted treatments.
Collapse
Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
- Department of Pediatrics, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Haolin Duan
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Hailan He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Juan Xiong
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Ying Wang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Guoli Wang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Karlmax Kiprotich
- Department of Epidemiology and Medical Statistics, School of Public Health, Moi University, Eldoret, Kenya
| | - Olumuyiwa A. Bamgbade
- Department of Anesthesiology and Pharmacology, University of British Columbia, Vancouver, BC, Canada
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
- *Correspondence: Fei Yin
| |
Collapse
|
5
|
Borowicz-Reutt KK. Effects of Antiarrhythmic Drugs on Antiepileptic Drug Action-A Critical Review of Experimental Findings. Int J Mol Sci 2022; 23:ijms23052891. [PMID: 35270033 PMCID: PMC8911389 DOI: 10.3390/ijms23052891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 02/28/2022] [Accepted: 03/04/2022] [Indexed: 01/27/2023] Open
Abstract
Severe cardiac arrhythmias developing in the course of seizures increase the risk of SUDEP (sudden unexpected death in epilepsy). Hence, epilepsy patients with pre-existing arrhythmias should receive appropriate pharmacotherapy. Concomitant treatment with antiarrhythmic and antiseizure medications creates, however, the possibility of drug–drug interactions. This is due, among other reasons, to a similar mechanism of action. Both groups of drugs inhibit the conduction of electrical impulses in excitable tissues. The aim of this review was the analysis of such interactions in animal seizure models, including the maximal electroshock (MES) test in mice, a widely accepted screening test for antiepileptic drugs.
Collapse
Affiliation(s)
- Kinga K Borowicz-Reutt
- Independent Unit of Experimental Neuropathophysiology, Department of Toxicology, Medical University of Lublin, 20-090 Lublin, Poland
| |
Collapse
|
6
|
Nano-ivabradine averts behavioral anomalies in Huntington's disease rat model via modulating Rhes/m-tor pathway. Prog Neuropsychopharmacol Biol Psychiatry 2021; 111:110368. [PMID: 34087391 DOI: 10.1016/j.pnpbp.2021.110368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 05/14/2021] [Accepted: 05/26/2021] [Indexed: 01/24/2023]
Abstract
Huntington's disease (HD) is characterized by abnormal involuntary movements together with cognitive impairment and disrupted mood changes. 3-nitropropionic acid (3-NP) is one of the chemo-toxic models used to address the striatal neurotoxicity pattern encountered in HD. This study aims to explain the neuroprotective effect of nano-formulated ivabradine (nano IVA) in enhancing behavioral changes related to 3-NP model and to identify the involvement of ras homolog enriched striatum (Rhes)/mammalian target of rapamycin (m-Tor) mediated autophagy pathway. Rats were divided into 6 groups, the first 3 groups received saline (control), ivabradine (IVA), nano IVA respectively, the fourth received a daily dose of 3-NP (20 mg/kg, s.c) for 2 weeks, the fifth received 3-NP + IVA (1 mg/kg, into the tail vein, every other day for 1 week) and the last group received 3-NP + nano IVA (1 mg/kg, i.v, every other day for 1 week). Interestingly, nano IVA reversed motor disabilities, improved memory function and overcame the psychiatric changes. It boosted expression of autophagy markers combined with down regulation of Rhes, m-Tor and b-cell lymphoma 2 protein levels. Also, it restored the normal level of neurotransmitters and myocardial function related-proteins. Histopathological examination revealed a preserved striatal structure with decreased number of darkly-degenerated neurons. In conclusion, the outcomes of this study provide a well-recognized clue for the promising neuroprotective effect of IVA and the implication of autophagy and Rhes/m-Tor pathways in the 3-NP induced HD and highlight the fact that nano formulations of IVA would be an auspicious approach in HD therapy.
Collapse
|
7
|
The HCN channel as a pharmacological target: Why, where, and how to block it. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:173-181. [PMID: 34303730 DOI: 10.1016/j.pbiomolbio.2021.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 06/22/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022]
Abstract
Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, expressed in a variety of cell types and in all tissues, control excitation and rhythm. Since their discovery in neurons and cardiac pacemaker cells, they attracted the attention of medicinal chemistry and pharmacology as novel targets to shape (patho)physiological mechanisms. To date, ivabradine represents the first-in-class drug as specific bradycardic agent in cardiac diseases; however, new applications are emerging in parallel with the demonstration of the involvement of different HCN isoforms in central and peripheral nervous system. Hence, the possibility to target specific isoforms represents an attractive development in this field; indeed, HCN1, HCN2 or HCN4 specific blockers have shown promising features in vitro and in vivo, with remarkable pharmacological differences likely depending on the diverse functional role and tissue distribution. Here, we show a recently developed compound with high potency as HCN2-HCN4 blocker; because of its unique profile, this compound may deserve further investigation.
Collapse
|
8
|
Iacone Y, Morais TP, David F, Delicata F, Sandle J, Raffai T, Parri HR, Weisser JJ, Bundgaard C, Klewe IV, Tamás G, Thomsen MS, Crunelli V, Lőrincz ML. Systemic administration of ivabradine, a hyperpolarization-activated cyclic nucleotide-gated channel inhibitor, blocks spontaneous absence seizures. Epilepsia 2021; 62:1729-1743. [PMID: 34018186 PMCID: PMC9543052 DOI: 10.1111/epi.16926] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are known to be involved in the generation of absence seizures (ASs), and there is evidence that cortical and thalamic HCN channel dysfunctions may have a proabsence role. Many HCN channel blockers are available, but their role in ASs has been investigated only by localized brain injection or in in vitro model systems due to their limited brain availability. Here, we investigated the effect on ASs of orally administered ivabradine (an HCN channel blocker approved for the treatment of heart failure in humans) following injection of the P-glycoprotein inhibitor elacridar, which is known to increase penetration into the brain of drug substrates for this efflux transporter. The action of ivabradine was also tested following in vivo microinjection into the cortical initiation network (CIN) of the somatosensory cortex and in the thalamic ventrobasal nucleus (VB) as well as on cortical and thalamocortical neurons in brain slices. METHODS We used electroencephalographic recordings in freely moving Genetic Absence Epilepsy Rats From Strasbourg (GAERSs) to assess the action of oral administration of ivabradine, with and without elacridar, on ASs. Ivabradine was also microinjected into the CIN and VB of GAERSs in vivo and applied to Wistar CIN and GAERS VB slices while recording patch-clamped cortical Layer 5/6 and thalamocortical neurons, respectively. RESULTS Oral administration of ivabradine markedly and dose-dependently reduced ASs. Ivabradine injection into CIN abolished ASs and elicited small-amplitude 4-7-Hz waves (without spikes), whereas in the VB it was less potent. Moreover, ivabradine applied to GAERS VB and Wistar CIN slices selectively decreased HCN channel-dependent properties of cortical Layer 5/6 pyramidal and thalamocortical neurons, respectively. SIGNIFICANCE These results provide the first demonstration of the antiabsence action of a systemically administered HCN channel blocker, indicating the potential of this class of drugs as a novel therapeutic avenue for ASs.
Collapse
Affiliation(s)
- Yasmine Iacone
- Neuroscience ResearchH. Lundbeck A/S, ValbyCopenhagenDenmark
- Biomedical SciencesFaculty of Health and Medical SciencesCopenhagen UniversityCopenhagenDenmark
| | - Tatiana P. Morais
- Neuroscience DivisionSchool of BiosciencesCardiff UniversityCardiffUK
| | - François David
- Integrative Neuroscience and Cognition CenterUniversity of ParisParisFrance
| | | | - Joanna Sandle
- Department of Anatomy, Physiology, and NeuroscienceMTA‐SZTE Research Group for Cortical MicrocircuitsUniversity of SzegedSzegedHungary
| | - Timea Raffai
- Department of Physiology, Anatomy, and NeuroscienceFaculty of SciencesUniversity of SzegedSzegedHungary
- Department of PhysiologyFaculty of MedicineUniversity of SzegedSzegedHungary
| | | | | | | | | | - Gábor Tamás
- Department of Anatomy, Physiology, and NeuroscienceMTA‐SZTE Research Group for Cortical MicrocircuitsUniversity of SzegedSzegedHungary
| | | | - Vincenzo Crunelli
- Neuroscience DivisionSchool of BiosciencesCardiff UniversityCardiffUK
- Department of Physiology and BiochemistryFaculty of Medicine and SurgeryUniversity of MaltaMsidaMalta
| | - Magor L. Lőrincz
- Neuroscience DivisionSchool of BiosciencesCardiff UniversityCardiffUK
- Department of Physiology, Anatomy, and NeuroscienceFaculty of SciencesUniversity of SzegedSzegedHungary
- Department of PhysiologyFaculty of MedicineUniversity of SzegedSzegedHungary
| |
Collapse
|
9
|
Amstetter D, Badt F, Rubi L, Bittner RE, Ebner J, Uhrin P, Hilber K, Koenig X, Todt H. The bradycardic agent ivabradine decreases conduction velocity in the AV node and in the ventricles in-vivo. Eur J Pharmacol 2021; 893:173818. [PMID: 33345856 DOI: 10.1016/j.ejphar.2020.173818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 12/02/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
Ivabradine blocks hyperpolarisation-activated cyclic nucleotide-gated (HCN) channels, thereby lowering the heart rate, an action that is used clinically for the treatment of heart failure and angina pectoris. We and others have shown previously that ivabradine, in addition to its HCN channel blocking activity, also inhibits voltage-gated Na channels in vitro at concentrations that may be clinically relevant. Such action may reduce conduction velocity in cardiac atria and ventricles. Here, we explore the effect of administration of ivabradine on parameters of ventricular conduction and repolarization in the surface ECG of anesthetized mice. We found that 5 min after i.p. administration of 10 mg/kg ivabradine spontaneous heart rate had declined by ~13%, which is within the range observed in human clinical studies. At the same time a significant increase in QRS duration by ~18% was observed, suggesting a reduction in ventricular conduction velocity. During transesophageal pacing at heart rates between 100 and 220 beats/min there was no obvious rate-dependence of ivabradine-induced QRS prolongation. On the other hand, ivabradine produced substantial rate-dependent slowing of AV nodal conduction. We conclude that ivabradine prolongs conduction in the AV-node and in the ventricles in vivo.
Collapse
Affiliation(s)
- Daniel Amstetter
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Florian Badt
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Lena Rubi
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Janine Ebner
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Pavel Uhrin
- Department of Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, Austria
| | - Karlheinz Hilber
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Xaver Koenig
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria.
| |
Collapse
|
10
|
Testing broad-spectrum and isoform-preferring HCN channel blockers for anticonvulsant properties in mice. Epilepsy Res 2020; 168:106484. [DOI: 10.1016/j.eplepsyres.2020.106484] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/23/2020] [Accepted: 10/05/2020] [Indexed: 12/19/2022]
|
11
|
Yongning Z, Xianguang L, Hengling C, Su C, Fang L, Chenhong L. The hyperpolarization-activated cyclic nucleotide-gated channel currents contribute to oxaliplatin-induced hyperexcitability of DRG neurons. Somatosens Mot Res 2020; 38:11-19. [PMID: 33092457 DOI: 10.1080/08990220.2020.1834376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Humans are likely to experience mechanical allodynia and cold hyperalgesia after oxaliplatin intravenous injection. The mechanism by which oxaliplatin leads to these side effects is unknown. Since the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are involved in the automatic depolarization of action potentials, we speculated that HCN channels are involved in oxaliplatin-induced hyperalgesia through action potentials. Our results showed that the density of HCN channel currents and the excitability of dorsal root ganglion neurons both increased after oxaliplatin perfusion at the cellular level. The neuronal hyperexcitability could be alleviated by ivabradine. Ivabradine inhibited oxaliplatin-induced mechanical allodynia and cold hyperalgesia at the individual rat level. Oxaliplatin enhanced the function of HCN channels, which in turn promoted the automatic depolarization of action potentials. The acceleration of automatic depolarization excited the neurons and caused more rapid firing of action potentials. Therefore, the HCN channel is a potential therapeutic target for the hyperalgesia induced by oxaliplatin.
Collapse
Affiliation(s)
- Zhang Yongning
- The Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumour Diagnosis & Treatment, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, P.R. China
| | - Lin Xianguang
- The Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumour Diagnosis & Treatment, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, P.R. China
| | - Chen Hengling
- The Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumour Diagnosis & Treatment, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, P.R. China
| | - Chen Su
- The Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumour Diagnosis & Treatment, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, P.R. China
| | - Luo Fang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Li Chenhong
- The Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumour Diagnosis & Treatment, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, P.R. China
| |
Collapse
|
12
|
Kharouf Q, Phillips AM, Bleakley LE, Morrisroe E, Oyrer J, Jia L, Ludwig A, Jin L, Nicolazzo JA, Cerbai E, Romanelli MN, Petrou S, Reid CA. The hyperpolarization-activated cyclic nucleotide-gated 4 channel as a potential anti-seizure drug target. Br J Pharmacol 2020; 177:3712-3729. [PMID: 32364262 DOI: 10.1111/bph.15088] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/24/2020] [Accepted: 04/16/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by four genes (HCN1-4) with distinct biophysical properties and functions within the brain. HCN4 channels activate slowly at robust hyperpolarizing potentials, making them more likely to be engaged during hyperexcitable neuronal network activity seen during seizures. HCN4 channels are also highly expressed in thalamic nuclei, a brain region implicated in seizure generalization. Here, we assessed the utility of targeting the HCN4 channel as an anti-seizure strategy using pharmacological and genetic approaches. EXPERIMENTAL APPROACH The impact of reducing HCN4 channel function on seizure susceptibility and neuronal network excitability was studied using an HCN4 channel preferring blocker (EC18) and a conditional brain specific HCN4 knockout mouse model. KEY RESULTS EC18 (10 mg·kg-1 ) and brain-specific HCN4 channel knockout reduced seizure susceptibility and proconvulsant-mediated cortical spiking recorded using electrocorticography, with minimal effects on other mouse behaviours. EC18 (10 μM) decreased neuronal network bursting in mouse cortical cultures. Importantly, EC18 was not protective against proconvulsant-mediated seizures in the conditional HCN4 channel knockout mouse and did not reduce bursting behaviour in AAV-HCN4 shRNA infected mouse cortical cultures. CONCLUSIONS AND IMPLICATIONS These data suggest the HCN4 channel as a potential pharmacologically relevant target for anti-seizure drugs that is likely to have a low side-effect liability in the CNS.
Collapse
Affiliation(s)
- Qays Kharouf
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - A Marie Phillips
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.,School of Biosciences, University of Melbourne, Parkville, Victoria, Australia
| | - Lauren E Bleakley
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Emma Morrisroe
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Julia Oyrer
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Linghan Jia
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Andreas Ludwig
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Liang Jin
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Joseph A Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Elisabetta Cerbai
- Department of Neurosciences, Psychology, Drug Research and Child Health, (NEUROFARBA), University of Florence, Florence, Italy
| | - M Novella Romanelli
- Department of Neurosciences, Psychology, Drug Research and Child Health, (NEUROFARBA), University of Florence, Florence, Italy
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
13
|
Romanelli MN, Del Lungo M, Guandalini L, Zobeiri M, Gyökeres A, Árpádffy-Lovas T, Koncz I, Sartiani L, Bartolucci G, Dei S, Manetti D, Teodori E, Budde T, Cerbai E. EC18 as a Tool To Understand the Role of HCN4 Channels in Mediating Hyperpolarization-Activated Current in Tissues. ACS Med Chem Lett 2019; 10:584-589. [PMID: 30996800 DOI: 10.1021/acsmedchemlett.8b00587] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/06/2019] [Indexed: 12/31/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are membrane proteins encoded by four genes (HCN1-4) and widely distributed in the central and peripheral nervous system and in the heart. HCN channels are involved in several physiological functions, including the generation of rhythmic activity, and are considered important drug targets if compounds with isoform selectivity are developed. At present, however, few compounds are known, which are able to discriminate among HCN channel isoforms. The inclusion of the three-methylene chain of zatebradine into a cyclohexane ring gave a compound (3a) showing a 5-fold preference for HCN4 channels, and ability to selectively modulate Ih in different tissues. Compound 3a has been tested for its ability to reduce Ih and to interact with other ion channels in the heart and the central nervous system. Its preference for HCN4 channels makes this compound useful to elucidate the contribution of this isoform in the physiological and pathological processes involving hyperpolarization-activated current.
Collapse
Affiliation(s)
- Maria Novella Romanelli
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Martina Del Lungo
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Luca Guandalini
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Mehrnoush Zobeiri
- Institute of Physiology I, Westfälische Wilhelms-University Münster, Münster 48149, Germany
| | - András Gyökeres
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged H-6720, Hungary
| | - Tamás Árpádffy-Lovas
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged H-6720, Hungary
| | - Istvan Koncz
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged H-6720, Hungary
| | - Laura Sartiani
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Gianluca Bartolucci
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Silvia Dei
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Dina Manetti
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Elisabetta Teodori
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-University Münster, Münster 48149, Germany
| | - Elisabetta Cerbai
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence 50139, Italy
| |
Collapse
|
14
|
Cavalcante TMB, De Melo JDMA, Lopes LB, Bessa MC, Santos JG, Vasconcelos LC, Vieira Neto AE, Borges LTN, Fonteles MMF, Chaves Filho AJM, Macêdo D, Campos AR, Aguiar CCT, Vasconcelos SMM. Ivabradine possesses anticonvulsant and neuroprotective action in mice. Biomed Pharmacother 2019; 109:2499-2512. [DOI: 10.1016/j.biopha.2018.11.096] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 11/04/2018] [Accepted: 11/25/2018] [Indexed: 12/20/2022] Open
|
15
|
Sawicka KM, Wawryniuk A, Daniluk J, Karwan S, Florek-Łuszczki M, Chmielewski J, Łuszczki JJ. Influence of dronedarone (a class III antiarrhythmic drug) on the anticonvulsant potency of four classical antiepileptic drugs in the tonic-clonic seizure model in mice. J Neural Transm (Vienna) 2018; 126:115-122. [PMID: 30535773 PMCID: PMC6373245 DOI: 10.1007/s00702-018-1940-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/05/2018] [Indexed: 12/16/2022]
Abstract
Increasing evidence indicates that some antiarrhythmic drugs play a pivotal role in seizures, not only in vivo studies on animals, but also in clinical trials. Some of these antiarrhythmic drugs potentiate or alleviate the anticonvulsant action of the classical antiepileptic drugs. The aim of this study was to determine the influence of dronedarone (DRO-a multichannel blocker belonging to the class III of antiarrhythmic drugs) on the anticonvulsant effects of four standard antiepileptic drugs (carbamazepine, phenobarbital, phenytoin and valproate) in the tonic-clonic seizure model in mice. Potential acute adverse effects exerted by the antiepileptic drugs combined with DRO were evaluated in three behavioral tests (chimney, grip-strength and passive avoidance). To confirm the nature of interaction, total brain concentrations of antiepileptic drugs were measured. DRO (50 mg/kg, i.p.) significantly reduces the anticonvulsant potency of phenytoin (P < 0.05), having no impact on that of carbamazepine, phenobarbital and valproate in the tonic-clonic seizure model in mice. DRO (50 mg/kg) neither changed total brain concentrations of phenytoin in mice, nor affected normal behavior in experimental animals subjected to the chimney, grip-strength and passive avoidance tests. In conclusion, DRO should not be combined with phenytoin because it reduced the anticonvulsant effects of the latter drug in experimental animals. The combined administration of DRO with carbamazepine, phenobarbital and valproate resulted in neutral interaction between these drugs in the tonic-clonic seizure model in mice.
Collapse
Affiliation(s)
- Katarzyna M Sawicka
- Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland.,Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Agnieszka Wawryniuk
- Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland
| | - Jadwiga Daniluk
- Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland.,Pope John Paul II State School of Higher Education in Biala Podlaska, Biala Podlaska, Poland
| | | | | | - Jarosław Chmielewski
- Institute of Environmental Protection-National Research Institute in Warsaw, Warsaw, Poland
| | - Jarogniew J Łuszczki
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland. .,Isobolographic Analysis Laboratory, Institute of Rural Health, Lublin, Poland.
| |
Collapse
|
16
|
Kato AS, Witkin JM. Protein complexes as psychiatric and neurological drug targets. Biochem Pharmacol 2018; 151:263-281. [PMID: 29330067 DOI: 10.1016/j.bcp.2018.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/05/2018] [Indexed: 12/25/2022]
Abstract
The need for improved medications for psychiatric and neurological disorders is clear. Difficulties in finding such drugs demands that all strategic means be utilized for their invention. The discovery of forebrain specific AMPA receptor antagonists, which selectively block the specific combinations of principal and auxiliary subunits present in forebrain regions but spare targets in the cerebellum, was recently disclosed. This discovery raised the possibility that other auxiliary protein systems could be utilized to help identify new medicines. Discussion of the TARP-dependent AMPA receptor antagonists has been presented elsewhere. Here we review the diversity of protein complexes of neurotransmitter receptors in the nervous system to highlight the broad range of protein/protein drug targets. We briefly outline the structural basis of protein complexes as drug targets for G-protein-coupled receptors, voltage-gated ion channels, and ligand-gated ion channels. This review highlights heterodimers, subunit-specific receptor constructions, multiple signaling pathways, and auxiliary proteins with an emphasis on the later. We conclude that the use of auxiliary proteins in chemical compound screening could enhance the detection of specific, targeted drug searches and lead to novel and improved medicines for psychiatric and neurological disorders.
Collapse
Affiliation(s)
- Akihiko S Kato
- Neuroscience Discovery, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, USA.
| | - Jeffrey M Witkin
- Neuroscience Discovery, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, USA
| |
Collapse
|
17
|
Tae HS, Smith KM, Phillips AM, Boyle KA, Li M, Forster IC, Hatch RJ, Richardson R, Hughes DI, Graham BA, Petrou S, Reid CA. Gabapentin Modulates HCN4 Channel Voltage-Dependence. Front Pharmacol 2017; 8:554. [PMID: 28871229 PMCID: PMC5566583 DOI: 10.3389/fphar.2017.00554] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/07/2017] [Indexed: 12/18/2022] Open
Abstract
Gabapentin (GBP) is widely used to treat epilepsy and neuropathic pain. There is evidence that GBP can act on hyperpolarization-activated cation (HCN) channel-mediated Ih in brain slice experiments. However, evidence showing that GBP directly modulates HCN channels is lacking. The effect of GBP was tested using two-electrode voltage clamp recordings from human HCN1, HCN2, and HCN4 channels expressed in Xenopus oocytes. Whole-cell recordings were also made from mouse spinal cord slices targeting either parvalbumin positive (PV+) or calretinin positive (CR+) inhibitory neurons. The effect of GBP on Ih was measured in each inhibitory neuron population. HCN4 expression was assessed in the spinal cord using immunohistochemistry. When applied to HCN4 channels, GBP (100 μM) caused a hyperpolarizing shift in the voltage of half activation (V1/2) thereby reducing the currents. Gabapentin had no impact on the V1/2 of HCN1 or HCN2 channels. There was a robust increase in the time to half activation for HCN4 channels with only a small increase noted for HCN1 channels. Gabapentin also caused a hyperpolarizing shift in the V1/2 of Ih measured from HCN4-expressing PV+ inhibitory neurons in the spinal dorsal horn. Gabapentin had minimal effect on Ih recorded from CR+ neurons. Consistent with this, immunohistochemical analysis revealed that the majority of CR+ inhibitory neurons do not express somatic HCN4 channels. In conclusion, GBP reduces HCN4 channel-mediated currents through a hyperpolarized shift in the V1/2. The HCN channel subtype selectivity of GBP provides a unique tool for investigating HCN4 channel function in the central nervous system. The HCN4 channel is a candidate molecular target for the acute analgesic and anticonvulsant actions of GBP.
Collapse
Affiliation(s)
- Han-Shen Tae
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia
| | - Kelly M Smith
- School of Biomedical Sciences and Pharmacy, University of Newcastle, CallaghanNSW, Australia.,Hunter Medical Research Institute, New Lambton HeightsNSW, Australia
| | - A Marie Phillips
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia.,School of BioSciences, The University of Melbourne, ParkvilleVIC, Australia
| | - Kieran A Boyle
- Institute of Neuroscience and Psychology, University of GlasgowGlasgow, United Kingdom
| | - Melody Li
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia
| | - Ian C Forster
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia
| | - Robert J Hatch
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia
| | - Robert Richardson
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia
| | - David I Hughes
- Institute of Neuroscience and Psychology, University of GlasgowGlasgow, United Kingdom
| | - Brett A Graham
- School of Biomedical Sciences and Pharmacy, University of Newcastle, CallaghanNSW, Australia.,Hunter Medical Research Institute, New Lambton HeightsNSW, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia
| | - Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, ParkvilleVIC, Australia
| |
Collapse
|
18
|
Sawicka KM, Załuska K, Wawryniuk A, Załuska-Patel K, Szczyrek M, Drop B, Daniluk J, Szpringer M, Żółkowska D, Łuszczki JJ. Ivabradine attenuates the anticonvulsant potency of lamotrigine, but not that of lacosamide, pregabalin and topiramate in the tonic-clonic seizure model in mice. Epilepsy Res 2017; 133:67-70. [PMID: 28458102 DOI: 10.1016/j.eplepsyres.2017.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 03/28/2017] [Accepted: 04/15/2017] [Indexed: 11/16/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are involved not only in synaptic transmission and neuronal excitability under physiological conditions, but also in seizure activity. To determine the influence of ivabradine (an HCN channel inhibitor) on the anticonvulsant potency of four novel antiepileptic drugs (AEDs: lacosamide, lamotrigine, pregabalin and topiramate) in the mouse maximal electroshock-induced seizure (MES) model. Adult male albino Swiss mice were challenged with maximal electroconvulsions (electric current of 25mA delivered via auricular electrodes). Total brain concentrations of AEDs were measured with high-pressure liquid chromatography. Ivabradine (10mg/kg, i.p.) significantly reduced the anticonvulsant potency of lamotrigine by elevating the ED50 value of the AED from 7.48 (6.15-9.11) to 10.07 (8.85-11.45) mg/kg (P<0.05) in the mouse MES model. In contrast, ivabradine (10mg/kg, i.p.) did not significantly affect the anticonvulsant potency of lacosamide, pregabalin or topiramate in the mouse MES model. Additionally, ivabradine had no impact on total brain concentrations of all the studied AEDs in mice. A special caution is advised when combining ivabradine with lamotrigine in epilepsy patients due to the possible pharmacodynamic reduction of the anticonvulsant action of the later drug. The combinations of ivabradine with lacosamide, pregabalin and topiramate seem to be pharmacodynamic and neutral from a preclinical viewpoint.
Collapse
Affiliation(s)
- Katarzyna M Sawicka
- Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland; Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Katarzyna Załuska
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Agnieszka Wawryniuk
- Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland
| | | | - Michał Szczyrek
- Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland
| | - Bartłomiej Drop
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Jadwiga Daniluk
- Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland
| | - Monika Szpringer
- Faculty of Medicine and Health Sciences, The Jan Kochanowski University in Kielce, Kielce, Poland
| | - Dorota Żółkowska
- Department of Neurology, School of Medicine, University of California-Davis, Sacramento, CA, USA
| | | |
Collapse
|
19
|
Banzrai C, Nodera H, Okada R, Higashi S, Osaki Y, Kaji R. Modification of multiple ion channel functions in vivo by pharmacological inhibition: observation by threshold tracking and modeling. THE JOURNAL OF MEDICAL INVESTIGATION 2017; 64:30-38. [PMID: 28373625 DOI: 10.2152/jmi.64.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Maintenance of axonal excitability relies on complex balance by multiple ion currents, but its evaluation is limited by in vitro single channel neurophysiological study on overall behavior. We sought to evaluate behaviors of multiple ion currents by pharmacological blockade. The threshold tracking technique was used to measure multiple excitability indices on tail sensory nerve of normal male mice before and after administration of either BaCl2 or ivabradine. Mathematical modeling was used to identify the interval changes of the channel parameters. After administration of BaCl2 and ivabradine, the following changes were present: greater threshold changes of both depolarizing and hyperpolarizing threshold electrotonus by both; additionally, reduced S2 accommodation, reduced late subexcitability and increased superexcitability by BaCl2, increased S3 accommodation by ivabradine. Mathematical modelling implied reduction of slow K+ conductance, along with reduction of H conductance (Ih) by BaCl2; and reduction of Ih while augmentation of K+ conductances by ivabradine. Pharmacological blockade of a selective ion channel may be compensated by other ion channels. Unintended effects by ion channel modification could be caused by secondary current alteration by multiple ion channels. J. Med. Invest. 64: 30-38, February, 2017.
Collapse
|
20
|
Sawicka KM, Wawryniuk A, Zwolak A, Daniluk J, Szpringer M, Florek-Luszczki M, Drop B, Zolkowska D, Luszczki JJ. Influence of Ivabradine on the Anticonvulsant Action of Four Classical Antiepileptic Drugs Against Maximal Electroshock-Induced Seizures in Mice. Neurochem Res 2017; 42:1038-1043. [PMID: 28083847 PMCID: PMC5375969 DOI: 10.1007/s11064-016-2136-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/28/2016] [Accepted: 12/03/2016] [Indexed: 11/28/2022]
Abstract
Although the role of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in neuronal excitability and synaptic transmission is still unclear, it is postulated that the HCN channels may be involved in seizure activity. The aim of this study was to assess the effects of ivabradine (an HCN channel inhibitor) on the protective action of four classical antiepileptic drugs (carbamazepine, phenobarbital, phenytoin and valproate) against maximal electroshock-induced seizures in mice. Tonic seizures (maximal electroconvulsions) were evoked in adult male albino Swiss mice by an electric current (sine-wave, 25 mA, 0.2 s stimulus duration) delivered via auricular electrodes. Acute adverse-effect profiles of the combinations of ivabradine with classical antiepileptic drugs were measured in mice along with total brain antiepileptic drug concentrations. Results indicate that ivabradine (10 mg/kg, i.p.) significantly enhanced the anticonvulsant activity of valproate and considerably reduced that of phenytoin in the mouse maximal electroshock-induced seizure model. Ivabradine (10 mg/kg) had no impact on the anticonvulsant potency of carbamazepine and phenobarbital in the maximal electroshock-induced seizure test in mice. Ivabradine (10 mg/kg) significantly diminished total brain concentration of phenytoin and had no effect on total brain valproate concentration in mice. In conclusion, the enhanced anticonvulsant action of valproate by ivabradine in the mouse maximal electroshock-induced seizure model was pharmacodynamic in nature. A special attention is required when combining ivabradine with phenytoin due to a pharmacokinetic interaction and reduction of the anticonvulsant action of phenytoin in mice. The combinations of ivabradine with carbamazepine and phenobarbital were neutral from a preclinical viewpoint.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Dorota Zolkowska
- School of Medicine, University of California-Davis, Sacramento, California, USA
| | | |
Collapse
|
21
|
Silva FC, Paiva FA, Müller-Ribeiro FC, Caldeira HMA, Fontes MAP, de Menezes RCA, Casali KR, Fortes GH, Tobaldini E, Solbiati M, Montano N, Dias Da Silva VJ, Chianca DA. Chronic Treatment with Ivabradine Does Not Affect Cardiovascular Autonomic Control in Rats. Front Physiol 2016; 7:305. [PMID: 27507948 PMCID: PMC4960883 DOI: 10.3389/fphys.2016.00305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/06/2016] [Indexed: 12/05/2022] Open
Abstract
A low resting heart rate (HR) would be of great benefit in cardiovascular diseases. Ivabradine—a novel selective inhibitor of hyperpolarization-activated cyclic nucleotide gated (HCN) channels- has emerged as a promising HR lowering drug. Its effects on the autonomic HR control are little known. This study assessed the effects of chronic treatment with ivabradine on the modulatory, reflex and tonic cardiovascular autonomic control and on the renal sympathetic nerve activity (RSNA). Male Wistar rats were divided in 2 groups, receiving intraperitoneal injections of vehicle (VEH) or ivabradine (IVA) during 7 or 8 consecutive days. Rats were submitted to vessels cannulation to perform arterial blood pressure (AP) and HR recordings in freely moving rats. Time series of resting pulse interval and systolic AP were used to measure cardiovascular variability parameters. We also assessed the baroreflex, chemoreflex and the Bezold-Jarish reflex sensitivities. To better evaluate the effects of ivabradine on the autonomic control of the heart, we performed sympathetic and vagal autonomic blockade. As expected, ivabradine-treated rats showed a lower resting (VEH: 362 ± 16 bpm vs. IVA: 260 ± 14 bpm, p = 0.0005) and intrinsic HR (VEH: 369 ± 9 bpm vs. IVA: 326 ± 11 bpm, p = 0.0146). However, the chronic treatment with ivabradine did not change normalized HR spectral parameters LF (nu) (VEH: 24.2 ± 4.6 vs. IVA: 29.8 ± 6.4; p > 0.05); HF (nu) (VEH: 75.1 ± 3.7 vs. IVA: 69.2 ± 5.8; p > 0.05), any cardiovascular reflexes, neither the tonic autonomic control of the HR (tonic sympathovagal index; VEH: 0.91± 0.02 vs. IVA: 0.88 ± 0.03, p = 0.3494). We performed the AP, HR and RSNA recordings in urethane-anesthetized rats. The chronic treatment with ivabradine reduced the resting HR (VEH: 364 ± 12 bpm vs. IVA: 207 ± 11 bpm, p < 0.0001), without affecting RSNA (VEH: 117 ± 16 vs. IVA: 120 ± 9 spikes/s, p = 0.9100) and mean arterial pressure (VEH: 70 ± 4 vs. IVA: 77 ± 6 mmHg, p = 0.3293). Our results suggest that, in health rats, the long-term treatment with ivabradine directly reduces the HR without changing the RSNA modulation and the reflex and tonic autonomic control of the heart.
Collapse
Affiliation(s)
- Fernanda C Silva
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Franciny A Paiva
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Flávia C Müller-Ribeiro
- Laboratory of Hypertension, Institute of Biological Sciences, Department of Physiology and Biophysics, Federal University of Minas Gerais Belo Horizonte, Brazil
| | - Henrique M A Caldeira
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto Ouro Preto, Brazil
| | - Marco A P Fontes
- Laboratory of Hypertension, Institute of Biological Sciences, Department of Physiology and Biophysics, Federal University of Minas Gerais Belo Horizonte, Brazil
| | - Rodrigo C A de Menezes
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| | - Karina R Casali
- Laboratory of Biomedical Engineering, Institute of Science and Technology, Federal University of São Paulo São José dos Campos, Brazil
| | | | - Eleonora Tobaldini
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Monica Solbiati
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Nicola Montano
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan Milan, Italy
| | - Valdo J Dias Da Silva
- Department of Physiology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro Uberaba, Brazil
| | - Deoclécio A Chianca
- Laboratory of Cardiovascular Physiology, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro PretoOuro Preto, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro PretoOuro Preto, Brazil
| |
Collapse
|
22
|
Shafaroodi H, Barati S, Ghasemi M, Almasirad A, Moezi L. A role for ATP-sensitive potassium channels in the anticonvulsant effects of triamterene in mice. Epilepsy Res 2016; 121:8-13. [PMID: 26855365 DOI: 10.1016/j.eplepsyres.2016.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 01/05/2016] [Accepted: 01/16/2016] [Indexed: 12/13/2022]
Abstract
There are reports indicating that diuretics including chlorothiazide, furosemide, ethacrynic acid, amiloride and bumetanide can have anticonvulsant properties. Intracellular acidification appears to be a mechanism for the anticonvulsant action of some diuretics. This study was conducted to investigate whether or not triamterene, a K(+)-sparing diuretic, can generate protection against seizures induced by intravenous or intraperitoneal pentylenetetrazole (PTZ) models. And to see if, triamterene can withstand maximal electroshock seizure (MES) in mice. We also investigated to see if there is any connection between triamterene's anti-seizure effect and ATP-sensitive K(+) (KATP) channels. Five days triamterene oral administration (10, 20 and 40 mg/kg), significantly increased clonic seizure threshold which was induced by intravenous pentylenetetrazole. Triamterene (10, 20 and 40 mg/kg) treatment also increased the latency of clonic seizure and decreased its frequency in intraperitoneal PTZ model. Administration of triamterene (20 mg/kg) also decreased the incidence of tonic seizure in MES-induced seizure. Co-administration of a KATP sensitive channel blocker, glibenclamide, in the 6th day, 60 min before intravenous PTZ blocked triamterene's anticonvulsant effect. A KATP sensitive channel opener, diazoxide, enhanced triamterene's anti-seizure effect in both intravenous PTZ or MES seizure models. At the end, triamterene exerts anticonvulsant effect in 3 seizure models of mice including intravenous PTZ, intraperitoneal PTZ and MES. The anti-seizure effect of triamterene probably is induced through KATP channels.
Collapse
Affiliation(s)
- Hamed Shafaroodi
- Department of Pharmacology and Toxicology, Pharmaceutical Sciences Branch and Pharmaceutical Sciences Research Center, Islamic Azad University, Tehran, Iran
| | - Saghar Barati
- Department of Pharmacology and Toxicology, Pharmaceutical Sciences Branch and Pharmaceutical Sciences Research Center, Islamic Azad University, Tehran, Iran
| | - Mehdi Ghasemi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Ali Almasirad
- Department of Medicinal Chemistry, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran, Iran
| | - Leila Moezi
- Department of Pharmacology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; Nanomedicine and Nanobiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
| |
Collapse
|
23
|
Novella Romanelli M, Sartiani L, Masi A, Mannaioni G, Manetti D, Mugelli A, Cerbai E. HCN Channels Modulators: The Need for Selectivity. Curr Top Med Chem 2016; 16:1764-91. [PMID: 26975509 PMCID: PMC5374843 DOI: 10.2174/1568026616999160315130832] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 12/27/2022]
Abstract
Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, the molecular correlate of the hyperpolarization-activated current (If/Ih), are membrane proteins which play an important role in several physiological processes and various pathological conditions. In the Sino Atrial Node (SAN) HCN4 is the target of ivabradine, a bradycardic agent that is, at the moment, the only drug which specifically blocks If. Nevertheless, several other pharmacological agents have been shown to modulate HCN channels, a property that may contribute to their therapeutic activity and/or to their side effects. HCN channels are considered potential targets for developing drugs to treat several important pathologies, but a major issue in this field is the discovery of isoform-selective compounds, owing to the wide distribution of these proteins into the central and peripheral nervous systems, heart and other peripheral tissues. This survey is focused on the compounds that have been shown, or have been designed, to interact with HCN channels and on their binding sites, with the aim to summarize current knowledge and possibly to unveil useful information to design new potent and selective modulators.
Collapse
Affiliation(s)
- Maria Novella Romanelli
- University of Florence, Department of Neurosciences, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
| | | | | | | | | | | | | |
Collapse
|
24
|
Zolkowska D, Andres-Mach M, Prisinzano TE, Baumann MH, Luszczki JJ. Modafinil and its metabolites enhance the anticonvulsant action of classical antiepileptic drugs in the mouse maximal electroshock-induced seizure model. Psychopharmacology (Berl) 2015; 232:2463-79. [PMID: 25697861 PMCID: PMC4480820 DOI: 10.1007/s00213-015-3884-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/25/2015] [Indexed: 11/24/2022]
Abstract
RATIONALE Seizures occur when the excitability of brain circuits is not sufficiently restrained by inhibitory mechanisms. Although modafinil is reported to reduce GABA-activated currents and extracellular GABA levels in the brain, the drug exerts anticonvulsant effects in animal studies. OBJECTIVES The aim of this study was to determine the effects of modafinil and its metabolites (sulfone and carboxylic acid) on the anticonvulsant action of four classical antiepileptic drugs (AEDs)-carbamazepine (CBZ), phenobarbital (PB), phenytoin (PHT), and valproate (VPA). METHODS Anticonvulsant activity was assessed with the maximal electroshock seizure threshold (MEST) test and MES test in mice. Brain concentrations of AEDs were measured to ascertain any pharmacokinetic contribution to the observed anticonvulsant effects. RESULTS Intraperitoneal injection of 75 mg kg(-1) of modafinil or its metabolites significantly elevated the threshold for electroconvulsions in mice, whereas 50 mg kg(-1) of each compound enhanced the anticonvulsant activity of CBZ, PHT, and VPA, but not that of PB. A 25-mg kg(-1) dose of modafinil or its sulfone metabolite enhanced anticonvulsant activity of VPA. Modafinil and its metabolites (50 mg kg(-1)) did not alter total brain concentrations of PB and VPA but did elevate CBZ and PHT. CONCLUSIONS Enhancement of anticonvulsant actions of VPA by modafinil in the mouse MES model is a pharmacodynamic effect. Collectively, our data suggest that modafinil may be a safe and beneficial adjunct to the therapeutic effects of AEDs in human patients.
Collapse
Affiliation(s)
- Dorota Zolkowska
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, California USA
| | - Marta Andres-Mach
- Isobolographic Analysis Laboratory, Institute of Rural Health, Lublin, Poland
| | - Thomas E. Prisinzano
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas USA
| | - Michael H. Baumann
- Medicinal Chemistry Section, Intramural Research Program (IRP), NIDA, NIH, Baltimore, MD USA
| | - Jarogniew J. Luszczki
- Isobolographic Analysis Laboratory, Institute of Rural Health, Lublin, Poland ,Department of Pathophysiology, Medical University of Lublin, Ceramiczna 1, 20-150 Lublin, Poland
| |
Collapse
|