CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A nicotina (NIC) à o principal componente da fumaÃa do tabaco e considerada uma das substÃncias com maior poder de abuso. Um importante efeito farmacolÃgico da NIC à a induÃÃo de convulsÃes. Neste contexto, foi proposto que a administraÃÃo repetida de NIC à capaz de causar abrasamento, uma forma de sensibilizaÃÃo à manifestaÃÃo de alteraÃÃes comportamentais, dentre elas a convulsÃo, sendo usado como ferramenta para o estudo dos mecanismos de progressÃo para uma ampla gama de transtornos neuropsiquiÃtricos. Recentemente nosso grupo de pesquisa evidenciou que ratas na periadolescÃncia sÃo mais susceptÃveis aos efeitos do abrasamento por NIC mostrando a participaÃÃo de mecanismos prÃ-oxidantes neste processo. Baseado nestas evidÃncias, o presente trabalho objetivou estudar os possÃveis benefÃcios da administraÃÃo de N-acetilcisteina (NAC), uma droga antioxidante, na prevenÃÃo do abrasamento induzido por NIC. Para isto foram utilizadas ratas Wistar periadolescentes (60-80 g). Os animais receberam NIC (2mg/Kg/dia, v.o.); NAC (90, 180 ou 270 mg/Kg/dia, i.p.) sozinha ou associada a NIC (NAC+NIC) ou Ãgua destilada durante 19 dias (cinco dias consecutivos e dois de intervalo). O comportamento dos animais foi avaliado nos 1Â, 8 15 e 19 dias, atravÃs da Escala de Racine. Ao final do tratamento (19 dia) os animais tiveram o cÃrtex prÃ-frontal (CPF), hipocampo (HP) e corpo estriado (CE) dissecados para a avaliaÃÃo de parÃmetros oxidativos como atividade da SOD, nÃveis de GSH, nitrito e peroxidaÃÃo lipÃdica (TBARS). Os resultados mostraram que os animais tratados com NAC apresentaram diminuiÃÃo dos graus de convulsÃo na Escala de Racine. A administraÃÃo de NAC+NIC reduziu a atividade da SOD, enquanto os nÃveis de GSH foram significativamente aumentados nos grupos NAC e NAC+NIC. NAC+NIC reduziram a peroxidaÃÃo lipÃdica nÃo alterando os nÃveis de nitrito nos grupos estudados. Em conclusÃo nosso estudo mostrou que a NAC apresenta efeito protetor em animais expostos ao abrasamento induzido por nicotina. / Nicotine (NIC) is the major component of tobacco smoking being one of the most abused substances worldwide. One important pharmacological effect of NIC is the induction of seizures. In this context it was previously proposed that NIC repeated administration is capable of inducing kindling, a form of sensitization related to the induction of behavioral alterations, among then seizures. Kindling is being used as a tool for the study of progression in a wide range of neuropsychiatric disorders. Recently our research group evidenced that periadolescent female rats were more susceptible to NIC-induced kindling demonstrating a participation of prooxidant mechanisms in this response. Based on these evidences, the present study had the goal to study the benefits of the administration of N-acetylcysteine (NAC), an antioxidant drug, in the prevention of NIC-induced seizures. To do this, female Wistar periadolescent rats (60-80 g) were used. The animals were administered NIC (2mg/Kg/day, i.p.); NAC (90, 180 or 270 mg/Kg/day, i.p.) alone or combined with NIC (NAC+NIC) or distilled water during 19 days. The animalâs behavior was evaluated at 1st, 8th, 15th and 19th days, using Racine Scale (seizure grades 1 to 5). At the end of treatment (19th day), animals were killed and their prefrontal cortex, hippocampus and striatum dissected. Homogenates were used to evaluate SOD activity, GSH levels, nitrite levels (as an indirect nitric oxide measurement), and lipid peroxide generation by measuring the substances that react with thiobarbituric acid. Animals treated with NAC presented a decrement in seizure activity. The SOD activity levels were decreased in group that received NAC+NIC. On the other hand, GSH levels had a significant increment in both groups treated with NAC and NAC+NIC. The lipid peroxidation level was reduced in the group that received NAC+NIC, and there was no change in nitrite levels in any group. The conclusion was that NAC presented a neuroprotective effect when diminished the lipid peroxidation level in animals exposed to nicotine-induced kindling.
| Identifer | oai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:8424 |
| Date | 27 June 2014 |
| Creators | Adriana Mary Nunes Costa |
| Contributors | Danielle MacÃdo Gaspar, Pedro Braga Neto, LÃlia Maria Carneiro CÃmara |
| Publisher | Universidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em Farmacologia, UFC, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC |
| Rights | info:eu-repo/semantics/openAccess |
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