Protection of the aged substantia nigra of the rat against oxidative damage by (-)-deprenyl

Abstract

(1) We have studied the effect of (-)-deprenyl on the oxidative damage that the rat substantia nigra suffers during aging. (2) (-)-Deprenyl (2 mg kg-1, three times a week) administered for two months, beginning at 22 months of age, produced a significant increase in tyrosine hydroxylase (TH) activity (2.67 ± 0.40 and 3.64 ± 0.38 nmol mg-1 protein h-1 in untreated aged rats and treated aged rats respectively, P<0.05) and in TH amount (0.072 ± 0.012 and 0.128 ± 0.38 absorbance 405 nm in untreated aged and treated aged rats respectively, P<0.05). (3) The proteins of aged rat substantia nigra showed a significant decrease of carbonyl groups in treated animals compared with saline-injected control rats (136.2 ± 21.8 and 71.5 ± 13.2 c.p.m. μg-1 protein in untreated aged and treated aged rats respectively, P<0.05). (4) The carbonyl groups measured in TH enzyme showed a statistically significant decrease (42.3%) after (-)-deprenyl treatment (471.4 ± 73.0 and 271.9 ± 50.00 c.p.m. in untreated aged and treated aged rats respectively, P<0.001). (5) All these results suggest that oxidative damage produced during aging is prevented by (-)-deprenyl treatment and could explain the effect of this drug in Parkinson's disease (PD) and other degenerative diseases such as Alzheimer's disease.