Effects of N-propargyl-1-(R)aminoindan (rasagiline) in models of motor and cognition disorders
N-propargyl-1-(R)aminoindan (rasagiline) is a new and selective irreversible MAO-B inhibitor, currently being considered as the mesylate salt for potential therapy in certain neurological disorders. It has been studied in animal models of cognition and mo
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z. Speiser', R. Levy\ and S. Cohen! 1 Department of Physiology and Pharmacology, Tel Aviv University, and 2Teva Pharmaceutical Industries, Ud., Corporate R&D Division, Kiryat Nordau, Netanya, Israel
Summary. N-propargyl-1-(R)aminoindan (rasagiline) is a new and selective irreversible MAO-B inhibitor, currently being considered as the mesylate salt for potential therapy in certain neurological disorders. It has been studied in animal models of cognition and motor dysfunction. Its ability to restore normal motor activity was determined in models of acute drug-induced dopaminergic dysfunction: Its effects in improving cognition and memory deficits was studied in adult and senescent rats that had been exposed to prolonged hypoxia, then subjected to the passive and active avoidance tests. In a-methylp-tyrosine (a-MpT)-induced hypokinesia (100-120mg/kg, i.p.) pretreatment with rasagiline at 2.5 mg/kg i.p. restored motor activity to control level. But pretreatment with reserpine abolished the protective effect of rasagiline. Rasagiline at 0.5 mg/kg/day was protective against a-MpT also in hypoxialesioned rats. In haloperidol-induced catalepsy in rats (1.5 mg/kg, s.c.) or mice (4-6 mg/kg s.c.), rasagiline improved recovery of normallocomotion, gait and coordination at 0.4-2.4mg/kg i.p. and 1.8-15mg/kg i.p., respectively. In amphetamine-induced stereotypy (0.6mg/kg s.c.), rasagiline potentiated this effect at 1.5 mg/kg i.p. In hypoxia-induced impairment of memory and learning, rasagiline at 0.32-0.5 mg/kg/day per os improved performance of adult rats in passive and active avoidance, and of senescent rats in active avoidance. Selegiline was either ineffective or less effective at equivalent doses. Racemic N-propargyl-1-aminoindan (AGN-1135), besides being of lower potency, had a different dose-dependency than rasagiline in antagonizing haloperidolinduced catalepsy or a-MpT-induced hypokinesia. l-(R)aminoindan ((R)AI), a metabolite of rasagiline, in relatively high doses produced effects that were distinct in certain respects from those of rasagiline.
Introduction Among the few selective inhibitors of monoamine oxidase type B is Npropargyl-1-aminoindan (PAI), appearing in literature reports under the code name AGN-1135 (Finberg et a1., 1981; Kalir et a1., 1981; Finberg and Youdim, J. P. M. Finberg et al. (eds.), MAO — The Mother of all Amine Oxidases © Springer-Verlag Wien 1998
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1985; Heikkila et al., 1985; Riederer and Youdim, 1986). The findings by these authors prompted the resolution of AGN-1135 into its two optical enantiomers, N-propargyl-1-(R)( + )aminoindan ((R)PAI), and N-propargyl-1(S)( - )aminoindan ((S)PAI). (R)PAI being the more potent and also the more selective member, having an ICso ratio MAO-A/MAO-B of about 24 in rat brain homogenates and a corresponding ex vivo ED so ratio in the range of 20-70 depending on the experimental system used (Youdim et al., 1995). (R)PAI, henceforth referred to as rasagiline is currently being considered for potential therapy in certain neurological dis
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