Cysteamine attenuates iminodipropionitrile (IDPN) induced dyskinesia in rats

The present investigation was undertaken to study the effect of cysteamine on experimental dyskinesia in rats. The movement disorders were produced by intraperitoneal administration of iminodipropionitrile (IDPN) in the dose of 100 mg/kg per day for 11 days. Cysteamine was administered (i.p.), daily 30 minutes before IDPN in the doses of 25 mg/kg, 50 mg/kg and 100 mg/kg bodyweight in three different groups of rats. Twenty four hours after the last dose of IDPN, animals were observed for neurobehavioural changes including vertical and horizontal head weaving, circling, backwalking, grip strength and righting reflex. Immediately after behavioural studies brain specimens were collected for analysis of vitamin E and total glutathione levels. The results of behavioural studies showed that co-treatment with cysteamine protected rats against IDPN-induced dyskinesia. Our biochemical studies showed that IDPN produced a depletion of vitamin E in cerebrum, cerebellum and brain stem. Concomitant treatment with cysteamine in doses of 50 and 100 mg/kg attenuated IDPN-induced decrease in vitamin E in cerebrum and cerebellum. There was a significant decrease in cerebral glutathione in IDPN treated rats, which was attenuated by cysteamine. No significant change was observed in the glutathione levels in cerebellum and brain stem. Further studies are deemed necessary to elucidate the mode of action of cysteamine and to determine therapeutic and/or prophylactic value of this drug in the treatment of movement disorders.