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da Silva ALM, Nascimento CP, Azevedo JEC, Vieira LR, Hamoy AO, Tiago ACDS, Martins Rodrigues JC, de Araujo DB, Favacho Lopes DC, de Mello VJ, Hamoy M. Unmasking hidden risks: The surprising link between PDE5 inhibitors and seizure susceptibility. PLoS One 2023; 18:e0294754. [PMID: 38033148 PMCID: PMC10688920 DOI: 10.1371/journal.pone.0294754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Phosphodiesterase 5 inhibitors (PDE5i) are the first line treatment for erectile dysfunction; however, several articles and case reports have shown central nervous system effects, that can cause seizures in susceptible patients. This study aims to describe the changes caused by the use of Sildenafil and Tadalafil through the analysis of abnormalities expressed in the electrocorticogram (ECoG) of rats and evaluate the seizure threshold response and treatment of seizures with anticonvulsants. MATERIALS AND METHODS The study used 108 rats (Wistar). Before surgery for electrode placement in dura mater, the animals were randomly separated into 3 experiments for electrocorticogram analysis. Experiment 1: ECoG response to using PD5i (Sildenafil 20mg/kg and Tadalafil 2.6mg/kg p.o.). Experiment 2: ECoG response to the use of PD5i in association with Pentylenetetrazole (PTZ-30 mg/kg i.p.), a convulsive model. Experiment 3: ECoG response to anticonvulsant treatment (Phenytoin, Phenobarbital and Diazepam) of seizures induced by association IPDE5 + PTZ. All recordings were made thirty minutes after administration of the medication and analyzed for ten minutes, only once. We considered statistical significance level of *p<0.05, **p<0.01 and ***p < 0.001. RESULTS After administration of Sildenafil and Tadalafil, there were increases in the power of recordings in the frequency bands in oscillations in alpha (p = 0.0920) and beta (p = 0.602) when compared to the control group (p<0.001). After the use of Sildenafil and Tadalafil associated with PTZ, greater potency was observed in the recordings during seizures (p<0.001), however, the Sildenafil group showed greater potency when compared to Tadalafil (p<0.05). Phenobarbital and Diazepam showed a better response in controlling discharges triggered by the association between proconvulsant drugs. CONCLUSIONS PDE5i altered the ECoG recordings in the rats' motor cortexes, demonstrating cerebral asynchrony and potentiating the action of PTZ. These findings demonstrate that PDE5i can lower the seizure threshold.
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Affiliation(s)
- Alex Luiz Menezes da Silva
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Chirlene Pinheiro Nascimento
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Julianne Elba Cunha Azevedo
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Luana Rodrigues Vieira
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Akira Otake Hamoy
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Allan Carlos da Silva Tiago
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - João Cleiton Martins Rodrigues
- Laboratory of Experimental Neuropathology, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Daniella Bastos de Araujo
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Dielly Catrina Favacho Lopes
- Laboratory of Experimental Neuropathology, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Vanessa Jóia de Mello
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
| | - Moisés Hamoy
- Laboratory of Pharmacology and Toxicology of Natural Products, Institute of Biological Sciences, Federal University of Pará, UFPA, Belém, Pará, Brazil
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2
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Jourian S, Rahimi M, Manavi MA, Pahlevan-Fallahy MT, Mohammad Jafari R, Amini A, Dehpour AR. Possible Interaction of Opioidergic and Nitrergic Pathways in the Anticonvulsant Effect of Ivermectin on Pentylenetetrazole-Induced Clonic Seizures in Mice. Neurochem Res 2023; 48:885-894. [PMID: 36383324 DOI: 10.1007/s11064-022-03804-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 10/08/2022] [Accepted: 10/20/2022] [Indexed: 11/17/2022]
Abstract
Ivermectin (IVM) is an antiparasitic drug that primarily works by the activation of GABAA receptors. The potential pharmacological pathways behind the anti-convulsant effect of IVM haven't yet been identified. In this study, intravenous injection of pentylenetetrazole (PTZ)-induced clonic seizure in mice was investigated in order to assess the possible influence of IVM on clonic seizure threshold (CST). We also look at the function of the Opioidergic and nitrergic pathways in IVM anticonvulsant action on clonic seizure threshold. IVM (0.5, 1, 5, and 10 mg/kg, i.p.) raised the PTZ-induced CST, according to our findings. Furthermore, the ineffective dose of nitric oxide synthase inhibitors (L-NAME 10 mg/kg, i.p.), and (7-NI 30 mg/kg, i.p.) or opioidergic system agonist (morphine 0.25 mg/kg, i.p.) were able to amplify the anticonvulsive action of IVM (0.2 mg/kg, i.p.). Moreover, the anticonvulsant effect of IVM was reversed by an opioid receptor antagonist (naltrexone 1 mg/kg, i.p.). Furthermore, the combination of the ineffective dose of morphine as an opioid receptor agonist with either L-NAME (2 mg/kg, i.p.) or 7-NI (10 mg/kg, i.p.) and with an ineffective dose of IVM (0.2 mg/kg, i.p.) had a significant anticonvulsant effect. Taken together, IVM has anticonvulsant activity against PTZ-induced clonic seizures in mice, which may be mediated at least in part through the interaction of the opioidergic system and the nitric oxide pathway.
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Affiliation(s)
- Sina Jourian
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Rahimi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Amin Manavi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Taha Pahlevan-Fallahy
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Razieh Mohammad Jafari
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.
| | - Ali Amini
- The Chapman University School of Pharmacy (CUSP), Irvine, CA, USA
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran. .,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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3
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Hassanein EHM, Mohamed WR, Ahmed OS, Abdel-Daim MM, Sayed AM. The role of inflammation in cadmium nephrotoxicity: NF-κB comes into view. Life Sci 2022; 308:120971. [PMID: 36130617 DOI: 10.1016/j.lfs.2022.120971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/06/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022]
Abstract
Kidney diseases are major health problem and understanding the underlined mechanisms that lead to kidney diseases are critical research points with a marked potential impact on health. Cadmium (Cd) is a heavy metal that occurs naturally and can be found in contaminated food. Kidneys are the most susceptible organ to heavy metal intoxication as it is the main route of waste excretion. The harmful effects of Cd were previously well proved. Cd induces inflammatory responses, oxidative injury, mitochondrial dysfunction and disturbs Ca2+ homeostasis. The nuclear factor-kappa B (NF-κB) is a cellular transcription factor that regulates inflammation and controls the expression of many inflammatory cytokines. Therefore, great therapeutic benefits can be attained from NF-κB inhibition. In this review we focused on certain compounds including cytochalasin D, mangiferin, N-acetylcysteine, pyrrolidine dithiocarbamate, roflumilast, rosmarinic acid, sildenafil, sinapic acid, telmisartan and wogonin and certain plants as Astragalus Polysaccharide, Ginkgo Biloba and Thymus serrulatus that potently inhibit NF-κB and effectively counteracted Cd-associated renal intoxication. In conclusion, the proposed NF-κB involvement in Cd-renal intoxication clarified the underlined inflammation associated with Cd-nephropathy and the beneficial effects of NF-κB inhibitors that make them the potential to substantially optimize treatment protocols for Cd-renal intoxication.
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Affiliation(s)
- Emad H M Hassanein
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt
| | - Wafaa R Mohamed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt
| | - Osama S Ahmed
- Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt
| | - Mohamed M Abdel-Daim
- Department of Pharmaceutical Sciences, Pharmacy Program, Batterjee Medical College, P.O. Box 6231, Jeddah 21442, Saudi Arabia; Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, 41522 Ismailia, Egypt
| | - Ahmed M Sayed
- Biochemistry Laboratory, Chemistry Department, Faculty of Science, Assiut University, Egypt.
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Moradi Jafari A, Hassanpourezatti M. Influence of methadone on the anticonvulsant efficacy of valproate sodium gabapentin against maximal electroshock seizure in mice by regulation of brain MDA TNF-α. Front Neurol 2022; 13:920107. [PMID: 36081867 PMCID: PMC9445582 DOI: 10.3389/fneur.2022.920107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/26/2022] [Indexed: 11/19/2022] Open
Abstract
Methadone is the most frequently used opioid therapy worldwide, with controversial effects on oxidative stress homeostasis. This study investigated the effects of intraperitoneal (i.p.) co-administration of methadone (0.1, 0.3, 1, and 3 mg/kg) and valproate sodium (300 mg/kg) or gabapentin (50 mg/kg) in the mice maximal electroshock (MES)-induced seizure model. The adverse effect of drugs was assessed using the chimney test. The levels of tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) contents were measured in mice brains after a single seizure. Administration of methadone alone resulted in a significant reduction in the duration of hind limb extension (HLE) than that in the control group. Methadone pretreatment at doses of 0.1 and 0.3 mg/kg i.p. decreased, and at doses of 1 and 3 mg/kg i.p. had an increasing effect on anticonvulsant efficacy of gabapentin. Pretreatment with all doses of methadone significantly decreased the valproate anticonvulsive efficacy. At doses of 1 and 3 mg/kg i.p. methadone per se increased brain MDA levels after MES-induced seizure. Administration of methadone (0.3 mg/kg i.p.) enhanced and at 3 mg/kg decreased gabapentin effect on brain MDA level, but their co-treatment did not lead to further increase in MDA. Methadone at 0.3–3 mg/kg enhanced the effect of sodium valproate on MDA levels in the brain, but at all doses significantly potentiated its effect on brain TNF-α levels. The drugs did not produce any side effects on motor coordination in experimental animals. In conclusion, methadone showed different effects on anticonvulsant actions of gabapentin and valproate through regulation of brain levels of MDA and TNF-α.
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5
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Zirak MR, Rahimian R, Mousavizadeh K, Dehpour AR. Mechanisms underlie the proconvulsant effects of sildenafil. Biomed Pharmacother 2020; 134:111142. [PMID: 33360157 DOI: 10.1016/j.biopha.2020.111142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/05/2020] [Accepted: 12/10/2020] [Indexed: 11/19/2022] Open
Affiliation(s)
- Mohammad Reza Zirak
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Reza Rahimian
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada.
| | - Kazem Mousavizadeh
- Cellular and Molecular Research Center and Department of Molecular Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Pourshadi N, Rahimi N, Ghasemi M, Faghir-Ghanesefat H, Sharifzadeh M, Dehpour AR. Anticonvulsant Effects of Thalidomide on Pentylenetetrazole-Induced Seizure in Mice: A Role for Opioidergic and Nitrergic Transmissions. Epilepsy Res 2020; 164:106362. [PMID: 32447240 DOI: 10.1016/j.eplepsyres.2020.106362] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/30/2020] [Accepted: 05/05/2020] [Indexed: 12/31/2022]
Abstract
Although accumulating evidence indicates that the immunomodulatory medication thalidomide exerts anticonvulsant properties, the mechanisms underlying such effects of thalidomide are still unknown. Our previous preclinical study suggested that nitric oxide (NO) signaling may be involved in the anticonvulsant effects of thalidomide in a mouse model of clonic seizure. Additionally, several studies have shown a modulatory interaction between thalidomide and opioids in opioids intolerance, nociception and neuropathic pain. However, it is unclear whether opioidergic transmission or its interaction with NO signaling is involved in the anticonvulsant effects of thalidomide. Given the fact that both opioidergic and nitrergic transmissions have bimodal modulatory effects on seizure thresholds, in the present study we explored the involvement of these signaling pathways in the possible anticonvulsant effects of thalidomide on the pentylenetetrazole (PTZ)-induced clonic seizure in mice. Our data showed that acute administration of thalidomide (5-50 mg/kg, i.p., 30 min prior PTZ injection) dose-dependently elevated PTZ-induced clonic seizure thresholds. Acute administration of low doses (0.5-3 mg/kg, i.p., 60 min prior PTZ) of morphine exerted anticonvulsant effects (P < 0.001), whereas higher doses (15-60 mg/kg, 60 min prior PTZ) had proconvulsant effects (P < 0.01). Acute administration of a non-effective anticonvulsant dose of morphine (0.25 mg/kg) prior non-effective dose of thalidomide (5 mg/kg) exerted a robust (P < 0.01) anticonvulsant effect. Administration of a non-effective proconvulsant dose of morphine (7.5 mg/kg) prior thalidomide (5 mg/kg) didn't affect clonic seizure thresholds. Acute administration of a non-effective dose of the opioid receptor antagonist naltrexone (1 mg/kg, i.p.) significantly prevented anticonvulsant effects of thalidomide (10 mg/kg, i.p.). Pretreatment with non-effective dose of the NO precursor L-arginine (60 mg/kg, i.p.) significantly (P < 0.01) reduced the anticonvulsant effects of combined low doses of morphine (0.25 mg/kg) and thalidomide (5 mg/kg). Conversely, pretreatment with non-effective doses of either non-selective (L-NAME, 5 mg/kg, i.p.) or selective neuronal (7-nitroindazole, 30 mg/kg, i.p.) NO synthase (NOS) inhibitors significantly augmented the anticonvulsant effects of combined low doses of thalidomide and morphine, whereas the inducible NOS inhibitor aminoguanidine (100 mg/kg, i.p.) did not exert such effect. Our results indicate that opioidergic transmission and its interaction with neuronal NO signaling may contribute to the anti-seizure activity of thalidomide in the mice PTZ model of clonic seizure.
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Affiliation(s)
- Nastaran Pourshadi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nastaran Rahimi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Ghasemi
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, United States
| | - Hedyeh Faghir-Ghanesefat
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sharifzadeh
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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7
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de Carvalho MAJ, Chaves-Filho A, de Souza AG, de Carvalho Lima CN, de Lima KA, Rios Vasconcelos ER, Feitosa ML, Souza Oliveira JV, de Souza DAA, Macedo DS, de Souza FCF, de França Fonteles MM. Proconvulsant effects of sildenafil citrate on pilocarpine-induced seizures: Involvement of cholinergic, nitrergic and pro-oxidant mechanisms. Brain Res Bull 2019; 149:60-74. [PMID: 31004733 DOI: 10.1016/j.brainresbull.2019.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 03/26/2019] [Accepted: 04/09/2019] [Indexed: 12/12/2022]
Abstract
Sildenafil is a phosphodiesterase 5 inhibitor used for the treatment of erectile dysfunction and pulmonary hypertension. Proconvulsant effect is a serious adverse event associated with sildenafil use. Here, we investigated the possible proconvulsant effects of sildenafil in pilocarpine (PILO)-induced seizures model, which mimics some aspects of temporal lobe epilepsy. We also evaluated sildenafil's effects on hippocampal markers related to PILO-induced seizure, for instance, acetylcholinesterase (AChE) activity, oxidative stress and nitric oxide (NO) markers, namely nitrite, inducible NO synthase (iNOS) and neuronal NOS (nNOS). The influences of muscarinic receptors blockade on sildenafil proconvulsant effects and brain nitrite levels were also evaluated. Male mice were submitted to single or repeated (7 days) sildenafil administration (2.5, 5, 10 and 20 mg/kg). Thirty minutes later, PILO was injected and mice were further evaluated for 1 h for seizure activity. Sildenafil induced a dose- and time-progressive proconvulsant effect in PILO-induced seizures. Sildenafil also potentiated the inhibitory effect of PILO in AChE activity and induced a further increase in nitrite levels and pro-oxidative markers, mainly in the hippocampus. Repeated sildenafil treatment also increased the hippocampal expression of iNOS and nNOS isoforms, while the blockade of muscarinic receptors attenuated both sildenafil-induced proconvulsant effect and brain nitrite changes. Our data firstly demonstrated the proconvulsant effect of sildenafil in PILO-model of seizures. This effect seems to be related to an increased cholinergic-nitrergic tone and pro-oxidative brain changes. Also, our findings advert to caution in using sildenafil for patients suffering from neurological conditions that reduces seizure threshold, such as epilepsy.
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Affiliation(s)
- Michele Albuquerque Jales de Carvalho
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Adriano Chaves-Filho
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Alana Gomes de Souza
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Camila Nayane de Carvalho Lima
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Klistenes Alves de Lima
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Emiliano Ricardo Rios Vasconcelos
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Mariana Lima Feitosa
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - João Victor Souza Oliveira
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Denia Alves Albuquerque de Souza
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Danielle S Macedo
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil; National Institute for Translational Medicine (INCT-TM, CNPq), Ribeirão Preto, Brazil
| | - Francisca Cléa Florenço de Souza
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Marta Maria de França Fonteles
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil; Pharmacy Department, Faculty of Dentistry, Nursing and Pharmacy, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
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8
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Kazemi Roodsari S, Bahramnejad E, Rahimi N, Aghaei I, Dehpour AR. Methadone's effects on pentylenetetrazole-induced seizure threshold in mice: NMDA/opioid receptors and nitric oxide signaling. Ann N Y Acad Sci 2019; 1449:25-35. [PMID: 30957236 DOI: 10.1111/nyas.14043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/22/2019] [Accepted: 02/04/2019] [Indexed: 12/25/2022]
Abstract
Methadone is a synthetic opioid used to treat opiate withdrawal and addiction. Studies have demonstrated the impact of methadone on seizure susceptibility. This study investigated the modulatory impacts of acute and subchronic (three times daily for 5 days) intraperitoneal methadone treatment on pentylenetetrazole-induced clonic seizure threshold (CST) in mice, as well as the involvement of the nitric oxide, N-methyl-d-aspartate (NMDA), and µ-opioid pathways. Acute administration of different doses of methadone (0.1, 0.3, 1, and 3 mg/kg) 45 min before CST significantly decreased the seizure threshold. Additionally, pretreatment with noneffective doses of an opioid receptor antagonist (naltrexone) and NMDA receptor antagonists (ketamine and MK-801) inhibited methadone's proconvulsive activity in the acute phase, while l-NAME (a nonspecific nitric oxide synthase (NOS) inhibitor) did not affect that activity. In the subchronic phase, methadone (3 mg/kg) demonstrated an anticonvulsive effect. Although subchronic pretreatment with noneffective doses of l-NAME and 7-nitroindazole (a specific neuronal NOS inhibitor) reversed methadone's anticonvulsive activity, aminoguanidine (a specific inducible NOS inhibitor), naltrexone, MK-801, and ketamine did not change methadone's anticonvulsive characteristic. Our results suggest that NMDA and µ-opioid receptors may be involved in methadone's proconvulsive activity in the acute phase, while methadone's anticonvulsive activity may be modulated by neuronal NOS in the subchronic phase.
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Affiliation(s)
- Soheil Kazemi Roodsari
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Erfan Bahramnejad
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nastaran Rahimi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Iraj Aghaei
- Department of Neuroscience, Neuroscience Research Center, Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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9
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Nieoczym D, Socała K, Wlaź P. Evaluation of the role of different neurotransmission systems in the anticonvulsant action of sildenafil in the 6 Hz-induced psychomotor seizure threshold test in mice. Biomed Pharmacother 2018; 107:1674-1681. [PMID: 30257385 DOI: 10.1016/j.biopha.2018.08.163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/28/2018] [Accepted: 08/31/2018] [Indexed: 12/14/2022] Open
Abstract
Sildenafil influences seizure activity in animal seizure models, and its both proconvulsant and anticonvulsant effects were reported. We previously found that this PDE5 inhibitor significantly increased seizure threshold for the 6 Hz-induced psychomotor seizures in mice and therefore we aimed to investigate the influence of some modulators of neurotransmitter receptors, i.e., diazepam (GABA/benzodiazepine receptor agonist), flumazenil (GABA/benzodiazepine receptor antagonist), N-methyl-d-aspartic acid (NMDA glutamate receptor agonist), CGP 37849 (NMDA receptor antagonist), metergoline (serotonin receptor antagonist), 8-cyclopentyl-1,3-dipropylxanthine (adenosine A1 receptor antagonist) and β-funaltrexamine (μ opioid receptor antagonist), on the anticonvulsant effect of sildenafil in this test. Additionally, we estimated influence of the studied compounds and their combinations with sildenafil on the muscular strength (assessed in the grip strength test) and motor coordination (assessed in the chimney test) in mice. Our results indicate that anticonvulsant properties of sildenafil in the 6 Hz test in mice might be related to its interactions with the GABAergic, glutamatergic, serotonergic and adenosinergic neurotransmission. We did not find interactions between sildenafil and μ opioid receptors. Neither the studied ligands nor their combinations with sildenafil impaired muscular strength and motor coordination. In conclusion, sildenafil has complex and extensive influence on neurotransmission and seizure generation in the CNS.
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Affiliation(s)
- Dorota Nieoczym
- Department of Animal Physiology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033, Lublin, Poland.
| | - Katarzyna Socała
- Department of Animal Physiology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033, Lublin, Poland
| | - Piotr Wlaź
- Department of Animal Physiology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033, Lublin, Poland
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Tawfik KM, Moustafa YM, El-Azab MF. Neuroprotective mechanisms of sildenafil and selenium in PTZ-kindling model: Implications in epilepsy. Eur J Pharmacol 2018; 833:131-144. [DOI: 10.1016/j.ejphar.2018.05.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 05/19/2018] [Accepted: 05/22/2018] [Indexed: 12/23/2022]
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11
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Effect of Tadalafil on Seizure Threshold and Activity of Antiepileptic Drugs in Three Acute Seizure Tests in Mice. Neurotox Res 2018; 34:333-346. [PMID: 29427285 PMCID: PMC6154210 DOI: 10.1007/s12640-018-9876-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 01/24/2018] [Accepted: 01/25/2018] [Indexed: 01/09/2023]
Abstract
Tadalafil, a selective phosphodiesterase type 5 inhibitor, is a long-acting oral agent for the treatment of erectile dysfunction of multiple etiologies. Although generalized tonic-clonic seizures were reported in a healthy man after taking tadalafil, the influence of tadalafil on seizure susceptibility has not been studied so far. Therefore, the aim of the present study was to investigate the effect of tadalafil on seizure threshold as well as on the activity of some first- and second-generation antiepileptic drugs in three acute seizure tests in mice. The obtained results showed that tadalafil, at the highest dose tested (20 mg/kg), significantly decreased the threshold for the first myoclonic twitch in the intravenous pentylenetetrazole (i.v. PTZ) seizure test. It did not affect the threshold for generalized clonic seizure and forelimb tonus in the i.v. PTZ, for tonic hindlimb extension in the maximal electroshock seizure threshold test, and for psychomotor seizure in the 6-Hz-induced seizure threshold test. Tadalafil did not alter the anticonvulsant activity of any of the studied antiepileptic drugs in electrically induced seizure tests. Interestingly, tadalafil potentiated the anticonvulsant activity of clonazepam and decreased the anticonvulsant activity of oxcarbazepine in the i.v. PTZ test. These interactions were pharmacodynamic in nature, as tadalafil did not alter clonazepam and oxcarbazepine concentrations both in serum and brain tissue. Furthermore, neither tadalafil alone nor its combinations with the studied antiepileptic drugs produced any significant impairment of motor coordination (assessed in the chimney test), muscular strength (investigated in the grip-strength test), and long-term memory (assessed in the passive avoidance task). In conclusion, tadalafil may increase the risk of myoclonic seizure and decrease the anticonvulsant efficacy of oxcarbazepine. Further studies are warranted to evaluate the safety of tadalafil usage in patients with epilepsy.
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12
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Verrotti A, Tambucci R, Striano P. Reply to 'Hitting two birds with one stone: daily scheduled opiods in preventing migraine and migraine-related epilepsy (migralepsy)'. Eur J Neurol 2016; 23:e60-1. [PMID: 27527520 DOI: 10.1111/ene.13063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 05/13/2016] [Indexed: 11/26/2022]
Affiliation(s)
- A Verrotti
- Department of Pediatrics, University of L'Aquila, L'Aquila, Italy
| | - R Tambucci
- Department of Pediatrics, University of L'Aquila, L'Aquila, Italy
| | - P Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, 'G. Gaslini' Institute, University of Genoa, Genova, Italy
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13
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Oxytocin is involved in the proconvulsant effects of Sildenafil: Possible role of CREB. Toxicol Lett 2016; 256:44-52. [DOI: 10.1016/j.toxlet.2016.05.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 05/11/2016] [Accepted: 05/18/2016] [Indexed: 01/24/2023]
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14
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Calcium Imaging of Neuronal Activity in Drosophila Can Identify Anticonvulsive Compounds. PLoS One 2016; 11:e0148461. [PMID: 26863447 PMCID: PMC4749298 DOI: 10.1371/journal.pone.0148461] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 01/18/2016] [Indexed: 12/17/2022] Open
Abstract
Although there are now a number of antiepileptic drugs (AEDs) available, approximately one-third of epilepsy patients respond poorly to drug intervention. The reasons for this are complex, but are probably reflective of the increasing number of identified mutations that predispose individuals to this disease. Thus, there is a clear requirement for the development of novel treatments to address this unmet clinical need. The existence of gene mutations that mimic a seizure-like behaviour in the fruit fly, Drosophila melanogaster, offers the possibility to exploit the powerful genetics of this insect to identify novel cellular targets to facilitate design of more effective AEDs. In this study we use neuronal expression of GCaMP, a potent calcium reporter, to image neuronal activity using a non-invasive and rapid method. Expression in motoneurons in the isolated CNS of third instar larvae shows waves of calcium-activity that pass between segments of the ventral nerve cord. Time between calcium peaks, in the same neurons, between adjacent segments usually show a temporal separation of greater than 200 ms. Exposure to proconvulsants (picrotoxin or 4-aminopyridine) reduces separation to below 200 ms showing increased synchrony of activity across adjacent segments. Increased synchrony, characteristic of epilepsy, is similarly observed in genetic seizure mutants: bangsenseless1 (bss1) and paralyticK1270T (paraK1270T). Exposure of bss1 to clinically-used antiepileptic drugs (phenytoin or gabapentin) significantly reduces synchrony. In this study we use the measure of synchronicity to evaluate the effectiveness of known and novel anticonvulsive compounds (antipain, isethionate, etopiside rapamycin and dipyramidole) to reduce seizure-like CNS activity. We further show that such compounds also reduce the Drosophila voltage-gated persistent Na+ current (INaP) in an identified motoneuron (aCC). Our combined assays provide a rapid and reliable method to screen unknown compounds for potential to function as anticonvulsants.
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Lin WH, He M, Baines RA. Seizure suppression through manipulating splicing of a voltage-gated sodium channel. ACTA ACUST UNITED AC 2015; 138:891-901. [PMID: 25681415 PMCID: PMC5014079 DOI: 10.1093/brain/awv012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Voltage-gated persistent sodium current (INaP) is a tractable target for antiepileptic drugs. Using a strategy focused on INaP reduction, Lin et al. identify 95 regulators of voltage-gated sodium channel splicing for which RNAi knockdown reduces seizure duration in Drosophila. Manipulation of splicing regulators could improve control of epilepsy. Seizure can result from increased voltage-gated persistent sodium current expression. Although many clinically-approved antiepileptic drugs target voltage-gated persistent sodium current, none exclusively repress this current without also adversely affecting the transient voltage-gated sodium current. Achieving a more selective block has significant potential for the treatment of epilepsy. Recent studies show that voltage-gated persistent sodium current amplitude is regulated by alternative splicing offering the possibility of a novel route for seizure control. In this study we identify 291 splicing regulators that, on knockdown, alter splicing of the Drosophila voltage-gated sodium channel to favour inclusion of exon K, rather than the mutually exclusive exon L. This change is associated with both a significant reduction in voltage-gated persistent sodium current, without change to transient voltage-gated sodium current, and to rescue of seizure in this model insect. RNA interference mediated knock-down, in two different seizure mutants, shows that 95 of these regulators are sufficient to significantly reduce seizure duration. Moreover, most suppress seizure activity in both mutants, indicative that they are part of well conserved pathways and likely, therefore, to be optimal candidates to take forward to mammalian studies. We provide proof-of-principle for such studies by showing that inhibition of a selection of regulators, using small molecule inhibitors, is similarly effective to reduce seizure. Splicing of the Drosophila sodium channel shows many similarities to its mammalian counterparts, including altering the amplitude of voltage-gated persistent sodium current. Our study provides the impetus to investigate whether manipulation of splicing of mammalian voltage-gated sodium channels may be exploitable to provide effective seizure control.
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Affiliation(s)
- Wei-Hsiang Lin
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - Miaomiao He
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - Richard A Baines
- Faculty of Life Sciences, University of Manchester, Manchester, UK
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16
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Nieoczym D, Socała K, Jedziniak P, Olejnik M, Wlaź P. Effect of sildenafil, a selective phosphodiesterase 5 inhibitor, on the anticonvulsant action of some antiepileptic drugs in the mouse 6-Hz psychomotor seizure model. Prog Neuropsychopharmacol Biol Psychiatry 2013; 47:104-10. [PMID: 23994662 DOI: 10.1016/j.pnpbp.2013.08.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/07/2013] [Accepted: 08/20/2013] [Indexed: 01/06/2023]
Abstract
Sildenafil, a selective phosphodiesterase 5 inhibitor (PDE5), has been recently reported to have both pro- and anticonvulsant action in various experimental models of seizures and epilepsy. Furthermore, it affects anticonvulsant action of some antiepileptic drugs (AEDs) in mice seizure tests and both pharmacodynamic and pharmacokinetic interactions were noted. The present study was carried out to investigate influence of sildenafil on the threshold for 6 Hz-induced psychomotor seizures in mice. Effect of sildenafil on activity of some AEDs, i.e., phenobarbital (PB), clonazepam (CZP), ethosuximide (ETS), valproic acid (VPA), tiagabine (TGB), oxcarbazepine (OXC) and levetiracetam (LEV), in 6 Hz test was also examined. Moreover, combination of sildenafil with LEV was investigated in terms of influence on motor coordination (determined by the chimney test), muscular strength (evaluated in the grip-strength test) and long-term memory (assessed in the passive avoidance task) in mice. To determine the type of pharmacological interaction between sildenafil and LEV, free plasma and total brain concentrations of this AED were determined by LC-MS/MS method. Sildenafil at a dose ranging from 10 to 40 mg/kg statistically increased psychomotor seizure threshold in mice. Moreover, sildenafil enhanced the anticonvulsant action of all the studied AEDs in this test. Interactions between this PDE5 inhibitor and PB, CZP, ETS, TGB and OXC seem to be pharmacodynamic. Since sildenafil increased free plasma and total brain concentration of LEV, interactions between these drugs have pharmacokinetic nature. This kind of interaction was also noted between sildenafil and VPA. Neither LEV (2.32 mg/kg) nor its co-administration with sildenafil (40 mg/kg) produced any significant changes in motor coordination, muscular strength and long-term memory in mice.
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Affiliation(s)
- Dorota Nieoczym
- Department of Animal Physiology, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
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17
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Payandemehr B, Rahimian R, Bahremand A, Ebrahimi A, Saadat S, Moghaddas P, Fadakar K, Derakhshanian H, Dehpour AR. Role of nitric oxide in additive anticonvulsant effects of agmatine and morphine. Physiol Behav 2013; 118:52-7. [DOI: 10.1016/j.physbeh.2013.05.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 04/17/2013] [Accepted: 05/07/2013] [Indexed: 11/28/2022]
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Haj-Mirzaian A, Hamzeh N, Javadi-Paydar M, Abdollahzadeh Estakhri MR, Dehpour AR. Resistance to depression through interference of opioid and nitrergic systems in bile-duct ligated mice. Eur J Pharmacol 2013; 708:38-43. [PMID: 23528353 DOI: 10.1016/j.ejphar.2013.03.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 02/25/2013] [Accepted: 03/08/2013] [Indexed: 11/24/2022]
Abstract
This study was done to investigate the effects of opioid and nitrergic systems on depression in an experimental model of cholestasis in mice, since elevated levels of these substances are seen in cholestatic subjects. Bile duct ligated (BDL) and sham-operated mice were forced to swim individually and the immobility time in the last 4 min of the 6 min test was evaluated to determine the effects of cholestasis on depression. To assess the possible involvement of endogenous opioids and nitric oxide (NO), effective and sub-effective doses of naltrexone an antagonist of opioid receptors, and N-nitro-l-arginine methyl ester (L-NAME) a non-specific NO synthase inhibitor, were administrated acutely and chronically to BDL and Sham-operated mice and then their immobility time was measured in forced swimming test (FST). The immobility time significantly decreased after bile-duct ligation. Naltrexone and L-NAME significantly reversed antidepressant like effect of cholestasis. Co-administration of sub-effective doses of naltrexone and L-NAME also reversed antidepressant effect in FST in chronic administration. But acute drug administration did not reverse the anti-depressant effect of cholestasis. We have shown that elevated levels of endogenous opioids and NO in cholestatic mice induce an anti depressant like effect, causing a reduction in the mice immobility time in FST. And the study also showed the predominant effect of opioid system and NO modulation of that in anti-depressant like effect of cholestasis.
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Affiliation(s)
- Arya Haj-Mirzaian
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Abstract
This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
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Nieoczym D, Socała K, Łuszczki JJ, Czuczwar SJ, Wlaz P. Influence of sildenafil on the anticonvulsant action of selected antiepileptic drugs against pentylenetetrazole-induced clonic seizures in mice. J Neural Transm (Vienna) 2012; 119:923-31. [PMID: 22315091 PMCID: PMC3401299 DOI: 10.1007/s00702-012-0767-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 01/22/2012] [Indexed: 12/30/2022]
Abstract
The aim of the present study was to investigate the effect of sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, on threshold for clonic seizures in mice. In addition, the effects of sildenafil on the anticonvulsant activity of selected antiepileptic drugs (AEDs), i.e., clonazepam (CZP), valproate (VPA), phenobarbital (PB), ethosuximide (ETS) and tiagabine (TGB), were also evaluated. The subcutaneous pentylenetetrazole (PTZ) test was used to determine the effects of sildenafil on convulsive susceptibility and the anticonvulsant activity of the studied AEDs in mice, while the acute side effects of sildenafil and its combinations with the studied AEDs were evaluated in the chimney test, step-through passive-avoidance task and grip-strength test in mice. Total brain concentrations of AEDs were also determined. Sildenafil (5–40 mg/kg) did not influence the threshold for PTZ-induced clonic seizures in mice, but increased the anticonvulsant activity of ETS in this test without any significant changes in the total brain concentration. The activity of the remaining AEDs was not significantly changed by sildenafil. Neither sildenafil alone nor its combinations with the studied AEDs produced any changes in the motor coordination, long-term memory and muscular strength in mice. Co-administration of sildenafil with ETS in male epileptic patients with co-existing erectile dysfunctions might lead to the pharmacodynamic interactions that may be beneficial for the patients. Combinations of sildenafil with CZP, VPA, PB and TGB appear to be neutral in terms of their influence on seizures.
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Affiliation(s)
- Dorota Nieoczym
- Department of Animal Physiology, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, Lublin, Poland
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Sildenafil influences the anticonvulsant activity of vigabatrin and gabapentin in the timed pentylenetetrazole infusion test in mice. Prog Neuropsychopharmacol Biol Psychiatry 2012; 39:129-35. [PMID: 22683320 DOI: 10.1016/j.pnpbp.2012.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 05/18/2012] [Accepted: 05/30/2012] [Indexed: 11/23/2022]
Abstract
Sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, has recently been reported to affect convulsant activity in some animal models of seizures and epilepsy. Moreover, its influence on the protective activity of some antiepileptic drugs (AEDs) was also noted. The aim of the present study was to investigate the effect of sildenafil on the anticonvulsant potential of gabapentin (GBP) and vigabatrin (VGB) in the timed intravenous (i.v.) pentylenetetrazole (PTZ) test in mice. The chimney test, the passive avoidance task and the grip strength test were used to estimate some possible side effects caused by the studied AEDs and their combinations with sildenafil. Total brain and free plasma concentrations of GBP and VGB were determined to evaluate the characteristics of interactions. Our studies revealed that GBP (25-100 mg/kg) increases the threshold for the forelimb tonic extension, whereas VGB raises thresholds both, for myoclonic (200-600 mg/kg) and generalized clonic (400-600 mg/kg) seizures in the used model of seizures. GBP at sub-effective dose of 12.5 mg/kg co-administered with sildenafil at doses of 10 and 20 mg/kg significantly increases the threshold for tonic seizures in the i.v. PTZ test in mice. Combination of sub-effective dose of VGB (200 mg/kg) with sildenafil at a dose of 5mg/kg also showed significant anticonvulsant activity against clonic seizures. The studied AEDs and their combinations with sildenafil did not produce any changes in the motor coordination, long-term memory and muscular strength in mice. Sildenafil did not influence total brain and free plasma concentrations of GBP and VGB. Interactions between the studied AEDs and sildenafil were pharmacodynamic in nature and for that reason they are worthy of consideration in the clinical practice.
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Matos G, Scorza FA, Cavalheiro EA, Tufik S, Andersen ML. PDEI‐5 for Erectile Dysfunction: A Potential Role in Seizure Susceptibility. J Sex Med 2012; 9:2111-21. [DOI: 10.1111/j.1743-6109.2012.02780.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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