| RESEARCH PAPER
|Year : 2000 | Volume
| Issue : 3 | Page : 235-238
Effect of pretreatment of nimodipine and nitrendipine on some dopaminergically mediated behaviours in rats
Khanzode D Suchet, Belorkar R Nandkishor, Gosavi D Devesh
Objective: To evaluate the effect of pretreatment of CNS specific calcium channel blockers (CCB) nimodipine and nitrendipine on some dopaminergically mediated behaviours like haloperidol induced catalepsy, methamphetamine induced stereotypy and conditioned avoidance response.
Methods: Catalepsy was induced by haloperidol (1mg/kg, i.p.) and scoring was done by the method of Costall and Naylor. Catalepsy score of each rat in the group (n=10) was taken to compute mean value. Onset time was noted. Similarly stereotypy was induced by methamphetamine (5 mg/kg, i.p.) and scoring was done by the method of Watanbe et al and effect on conditioned avoidance response (CAR) was noted using Cook's pole climbing apparatus. Test drugs nimodipine (4, 8 mg/ kg, i.p.) and nitrendipine (2.5, 5 mg/kg, i.p.) were given 1 hr. prior to the experiment.
Results: Nimodipine (4, 8 mg/kg, i.p.) and nitrendipine (2.5, 5 mg/kg, i.p.) reduced the onset of haloperidol induced catalepsy and potentiated catalepsy at different time intervals. Onset of methamphetamine induced stereotypy was delayed and score was inhibited significantly. There was blockade of CAR but unconditioned response was not affected by these drugs in the doses used in this experiment.
Conclusion: Nimodipine and nitrendipine may act through dopaminergic mechanism to potentiate catalepsy, inhibit stereotypy and block CAR.
Khanzode D Suchet
Source of Support: None, Conflict of Interest: None