Role of B-Type Monoamine Oxidase Inhibition in the Treatment of Parkinson’s Disease. In: Shah NS, Donald AG, editors. Movement Disorders. Boston: Springer US; 1986. pp. 53-81. [DOI: 10.1007/978-1-4684-5038-5_3]

(-)Deprenyl-medication: a strategy to modulate the age-related decline of the striatal dopaminergic system

(-)Deprenyl (Selegiline, Jumex, Eldepryl, Movergan), a close structural relative to phenylethylamine (PEA), is a drug with a unique pharmacological spectrum. (1) It is a highly potent and selective, irreversible inhibitor of B-type monoamine oxidase (MAO), a predominantly glial enzyme in the brain. The activity of this enzyme significantly increases with age. (-)Deprenyl, the first selective inhibitor of MAO-B described in literature, has become the universally used research tool for selectively blocking B-type MAO. It is the only MAO-B inhibitor in clinical use. (2) (-)Deprenyl interferes with the uptake of catecholamines and indirectly acting sympathomimetics because it is handled by the catecholaminergic neuron in a way similar to the physiological substances transported through the axonal end organ and vesicular membrane. The unique behavior of (-)deprenyl is that, in striking contrast to PEA and its relatives, it does not displace the transmitter from storage, ie, it is not a releaser. The net result is that (-)deprenyl inhibits the releasing effect of tyramine, and, at present, is the only safe MAO inhibitor that can be administered without dietary precautions. (3) Maintenance on (-)deprenyl selectively enhances superoxide dismutase (SOD) and catalase activity in the striatum. This effect is unrelated to its effect on MAO-B and the inhibitory effects of the drug on neurotransmitter uptake. (4) Maintenance on (-)deprenyl facilitates the activity of the nigrostriatal dopaminergic neurons with remarkable selectivity, and this effect, too, is unrelated to either its effects on MAO or on neurotransmitter uptake. (5) Maintenance on (-)deprenyl prevents the characteristic age-related morphological changes in the neuromelanin granules of the neurocytes in the substantia nigra. All in all, (-)deprenyl increases the activity of the nigrostriatal dopaminergic system and slows its age-related decline. Maintenance of male rats on (-)deprenyl delays the loss of the capacity to ejaculate, slows the decline of learning and memory, and significantly lengthens the life-span as compared with saline-treated rats. Parkinson's disease patients on levodopa plus (-)deprenyl (10 mg daily) live significantly longer than those on levodopa alone. (-)Deprenyl is the first drug that retards the progress of Parkinson's disease. Newly diagnosed Parkinson's disease patients maintained on (-)deprenyl need levodopa significantly later than their placebo-treated peers. Maintenance on (-)deprenyl improves significantly the performance of patients with Alzheimer's disease. It is concluded that Parkinson's disease and Alzheimer's disease patients need to be treated daily with 10 mg (-)deprenyl from diagnosis until death, irrespective of other medication.(ABSTRACT TRUNCATED AT 400 WORDS)

The pharmacology of selegiline ((-)deprenyl). New aspects

Male rats were treated from the end of their 2nd year of life either with saline (1 ml/kg, s.c.) (n = 66) or with deprenyl (0.25 mg/kg, s.c.) (n = 66) three times a week until death. Whereas none of the two-year-old saline-treated rats displayed full scale sexual activity, this appeared in 64 out of 66 rats on deprenyl. The longest living rat in the saline-treated group lived 164 weeks. The average lifespan of the group was 147.05 +/- 0.56 weeks. The shortest living animal in the (-)deprenyl-treated group lived 171 weeks and the longest living rat died during the 226th week of its life. The average lifespan was 191.91 +/- 2.31 weeks. This is the first instance that a well-aimed medication prolonged lifespan of members of a species beyond their maximum age of death (182 weeks in the rat). A close relation between sexual activity and lifespan was detected. Male rats (n = 94) selected from an 8-month old population as sexually inactive ones were found to be miserable learners. This group was treated either with saline (1 ml/kg, s.c.) (n = 46) or with (-)deprenyl (0.25 mg/kg, s.c.) (n = 48) three times a week for 36 weeks. Their performance in the shuttle box during 5 consecutive days was tested before and after treatment. The total number of conditioned avoidance responses (CAR) which remained unchanged in the saline-treated group (6.53 +/- 1.41 before and 5.98 +/- 1.15 after treatment) increased from 5.57 +/- 0.65 to 20.73 +/- 1.39 (p less than 0.001) in the (-)deprenyl-treated group of rats. (-)Deprenyl-treatment (0.25-2 mg/kg, s.c., daily for 21 days) increased superoxide dismutase (SOD) activity in the striatum of CFY rats, whereas clorgyline-treatment (0.1-1 mg/kg) inhibited it.