Abstract:
Recent evidence suggests that overactivity of central serotonin 5- HT2 and dopamine D2 receptors is involved in the pathogenesis of schizophrenia and that central serotonin 5 HT2 receptor antagonism has been associated with efficacy against negative symptoms of schizophrenia and a lower propensity to cause extrapyramidal side effects. Risperidone, an atypical antipsychotic agent has both dopamine D2 and serotonin 5- HT2 antagonistic activity. To demonstrate dopamine D2 receptor antagonism, risperidone was studied for its effect on apomorphine and methamphetamine induced stereotyped behavior in rats. Risperidone was also studied for its effect on 5- hydroxytryptophan induced head twitch activity in mice, a central serotonin 5- HT2 mediated behavior for demonstrating central 5-HT2 receptor antagonism. It was observed that risperidone antagonized the apomorphine and methamphetamine induced stereotyped behavior in rats as well as the 5- hydroxytryptophan (5-HT) induced head twitch activity in mice, in a dose dependent manner which shows that risperidone combines both central dopamine D2 and serotonin 5-HT2 receptor antagonism.
Keywords: Schizophrenia, D2 antagonism, 5- HT2 antagonism, Negative symptoms, Extrapyramidal side effects
Journal Authors
Chandrakant Sahebrao Waghmare 1, Sachin Kore 2
1 Professor & Head, Dept. of Pharmacology, Ashwini Rural Medical College & Hospital, Solapur. (Corresponding Author)
2 Assistant Professor, Dept. of Skin & V.D., KBN Institute of Medical Sciences, Gulbarga. (Co- Author)