Effects of L-deprenyl and amantadine in an MPTP-model of parkinsonism.

Mongolian gerbils of both sexes received a single daily dose of 40 mg/kg of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) over 4 consecutive days. On the fifth day the animals were treated with 15 mg/kg i.p. of L-deprenyl or amantadine or the combination of both drugs. At different time intervals (1, 2, 5 hours) the animals were sacrificed. In the caudate nuclei dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) were measured by an HPLC technique. MPTP affected the dopaminergic (HVA -25%) as well as the serotoninergic system (5-HT -54%, 5-HIAA -31%). L-deprenyl and amantadine accumulated DA and 5-HT in the MPTP affected caudates. Synergistic effects of the drug combination could be proven.