effects of l-arginine pre-treatment in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinson’s diseases in balb/c mice

background: parkinson’s disease (pd) is a common neurodegenerative disease resulting from the degeneration of dopaminergic (da) neurons in the substantia nigra pars compacta (snc). increasing evidence demonstrated that mice treated intranasally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (mptp) suffered impairments in motor functions associated with disruption of da neurons in snc conceivably analogous to those observed in pd. l-arginine has been proposed as a novel neuroprotective agent that plays protective roles in several models of neuronal cellular damage. this study aimed to evaluate the effects of l-arginine on the numerical density of dark neurons (dns) in the snc of balb/c mice subjected to mptp administration. methods: in the present study, we demonstrated that repeated treatment with l-arginine (300 mg/kg, i.p.) during 7 consecutive days attenuated the production of dns in snc of adult male balb/c mice infused with a single intranasal administration of mptp (1 mg/nostril). results: pre-treatment with l-arginine significantly decreased the numerical density of dns in snc of mice 21 days after intranasal mptp administration. conclusion: this investigation provides new insights in experimental models of pd, indicating that l-arginine represents a potential neuroprotective agent for the prevention of da neuron degeneration in snc observed in pd patients.