Proconvulsant effects of sildenafil citrate on pilocarpine-induced seizures: Involvement of cholinergic, nitrergic and pro-oxidant mechanisms.

Autor: de Carvalho MAJ; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., Chaves-Filho A; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., de Souza AG; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., de Carvalho Lima CN; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., de Lima KA; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., Rios Vasconcelos ER; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., Feitosa ML; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., Souza Oliveira JV; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., de Souza DAA; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., Macedo DS; 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., de Souza FCF; Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil., de França Fonteles MM; 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. Electronic address: martafonteles@yahoo.com.br.
Jazyk: angličtina
Zdroj: Brain research bulletin [Brain Res Bull] 2019 Jul; Vol. 149, pp. 60-74. Date of Electronic Publication: 2019 Apr 17.
DOI: 10.1016/j.brainresbull.2019.04.008
Abstrakt: 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.
(Copyright © 2019 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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