RESUMO
Background and Objective: Parkinson disease [PD] is the second most common neurologic disorder that results following degeneration of dopaminergic neurons in the pars compacta of substintia nigra [SNc]. The 1-methyl-1,2,3,6-tetrahydropiridine [MPTP] is a chemical neurotoxin that widely used in animal models of PD. This study was carried out to evaluate the numerical density of dark neurons [DNs] in the SNc in mice subjected to intraperitoneal and intranasal injection of different doses of MPTP
Methods: In this experimental study, 90 male adult BALB/c mice were randomly allocated int four experimental groups including: group 1 [MPTP was injected via i.p. at the dose of 20mg/kg per 2 hours for 4 times], group 2 [MPTP was injected via i.p. at the dose of 30mg/kg for 5 consecutive days], group 3 [MPTP was injected via i.n. at a single dose of 1mg/kg], group 4 [MPTP was injected via i.n. at a single dose of 1mg/kg], four sham and one normal groups. 20 days after the final injection, the animal's brain were removed and stained by toluidine blue. Numerical density of DNs was counted
Results: Intranasal injection of MPTP significantly increased density of dark neurons in the pars compacta of substintia nigra in compare to intraperitoneally injection of MPTP [P<0.05]
Conclusion: Intranasal injection of MPTP is more effective manner to induce degeneration of neurons in substintia nigra in animal model of Parkinson's disease