Rasagiline [N-propargyl-IR(+)-aminoindan; TVP1012] is a potent irreversible monoamine oxidase (MAO) inhibitor with selectivity for type B of the enzyme, which is being developed for treatment of Parkinson's disease. In this study we examined effects of rasagiline on CNS monoamine levels, modification of behavioural response to L-tryptophan, fluoxetine and L-DOPA, and reversal of reserpine syndrome. Reserpine-induced ptosis was reversed by rasagiline at doses above 2 mg.kg(-1) i.p., which inhibit MAO-A as well as MAO-B, but not at MAO-B-selective doses. However, combination of rasagiline (10 mg.kg(-1) i.p.) with L-DOPA or L-tryptophan (50 mg.kg(-1) i.p.), or rasagiline (10 mg.kg(-1) p.o.) with fluoxetine (10 mg.kg(-1) p.o.), did not induce the behavioural hyperactivity syndrome which is seen following inhibition of both MAO-A and MAO-B by tranylcypromine together with the monoamine precursors. Following oral administration, levels of noradrenaline (NA), 5-hydroxytryptamine (5-HT) and dopamine (DA) were unaffected in hippocampus and striatum after single doses of rasagiline up to 2 mg.kg(-1). Following chronic oral administration (21 days, one dose daily), levels of NA, 5-HT and DA in hippocampus and striatum were unaffected by rasagiline at doses up to I mg.kg(-1). Rasagiline does not modify CNS monoamine tissue levels or monoamine-induced behavioural syndromes at doses which selectively inhibit MAO-B but not MAO-A. (C) 2002 Elsevier Science Ltd. All rights reserved.