Análise da interação entre acetilcolina, dopamina e óxido nítrico sobre o comportamento motor em um modelo animal da doença de Parkinson

Abstract

The aim of this study was to evaluate the interaction between the neurotransmitters acetylcholine, dopamine and nitric oxide in basal ganglia of mice. Four experiments were conducted with six groups of eight Swiss mice, male, weighing 20-30g. In Experiment 1, animals were injected intraperitoneally (ip) with saline or haloperidol (1mg/kg) followed by ip application of saline or biperiden (2.5 and 10mg/kg). In Experiment 2, animals were injected intraperitoneally (ip) of saline or L-NOARG (40mg/kg) followed by ip application of saline or biperiden (2.5 and 10mg/kg). In Experiment 3, animals were injected intraperitoneally (ip) with saline or haloperidol (1mg/kg) followed by ip application of saline or tropicamide (2.5 and 10mg/kg). In Experiment 4, animals were injected intraperitoneally (ip) with saline or L-NOARG (40mg/kg) followed by ip application of saline or tropicamide (2.5 and 10mg/kg). After 30, 60 and 90 minutes of application of drugs, the animals were submitted for catalepsy in the bar. After 60 minutes an open field. In Experiment 1, saline + haloperidol group showed a longer catalepsy in relation to the others (Tukey's test p <0.05). The groups haloperidol + biperiden (2.5 and 10mg/kg) were shorter than the haloperidol catalepsy + saline (p <0.05). In Experiment 2, the group L-NOARG + saline showed longer catalepsy in relation to the others (p <0.05). The groups L-NOARG + biperiden (2.5 and 10mg/kg) showed less catalepsy time that L- NOARG + saline (p <0.05). In Experiment 3, haloperidol + saline group had longer catalepsy in relation to the others (p <0.05). The groups haloperidol + tropicamide (2.5 and 10mg/kg) were shorter than haloperidol catalepsy + saline (p <0.05). In Experiment 4, the group L-NOARG + saline showed longer catalepsy in relation to other groups tropicamide + L-NOARG (2.5 and 10mg/kg) showed less catalepsy time that L-NOARG + saline (p < 0.05). The dopamine antagonist, haloperidol, caused changes in motor behavior, leading to the decrease in catalepsy and horizontal scanning and vertical scanning. The antagonist of nitric oxide synthesis (NOS), L- NOARG caused the same changes, but more discreetly. Antagonists of muscarinic acetylcholine receptors (M1), biperiden and tropicamide (M4) reversed catalepsy and increased explotation induced horizontal and vertical.