Avaliação do efeito da administração intranasal de nicotina em modelo experimental da Doença de Parkinson induzido por 6-hidroxidopamina

Abstract

INTRODUCTION: Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Although the L-DOPA administration is the primary available therapy, its prolonged use is associated with adverse effects, highlighting the need for new therapeutic approaches. Epidemiological studies suggest that smoking may reduce the risk of PD, indicating a potential neuroprotective effect of nicotine. OBJECTIVE: To evaluate the effects of intranasal nicotine treatment on neuroprotection in an experimental model of PD induced by 6-OHDA in rats. METHODOLOGY: Adult male Wistar rats were subjected to unilateral lesion with 6-OHDA in the striatum and divided into experimental groups treated with intranasal nicotine or control vehicle. Motor function was assessed by behavioral tests, and the dopaminergic neurons degeneration was investigated by counting TH+ positive cells in the substantia nigra pars compacta. RESULTS: Intranasal administration of nicotine 15 days after injury showed anxiolytic effects in the 6-OHDA-induced Parkinson's disease model, but did not protected dopaminergic neurons. CONCLUSION: Considering that the literature describes that 15 days after induction of degeneration by 6-OHDA there is already degeneration in the substantia nigra, and that previous studies show the protective effect of nicotine in preventing dopaminergic damage, it is possible to conclude that nicotine does not exert a protective effect in advanced stages of dopaminergic degeneration, but an anxiolytic action, in the animal model.