REPORT Attenuation of apomorphine induced behavioral sensitization in rats pre-treated with tryptophan

Abstract

Psychostimulants substances, some of which are abused by humans, are generally believed to produce sensitization effects when they are repeatedly administered to animals. Apomorphine, a non-narcotic derivative of morphine, having agonistic property for dopamine in order to produce psycho stimulant-like effects. Meanwhile, chronic administration leads to behavioral sensitization. Therefore, present study destine to produce desensitization in animals by the repeated administration of tryptophan (100 mg/kg), thereafter treated with apomorphine (1.0 mg/kg) to observe the intensity of sensitization in rats pre-treated with tryptophan. Apomorphine on acute administration known to increase motor activity whereas repeated treatment of apomorphine initiates the sensitization of motor behavior. It is expected that the intensity of apomorphine induced sensitization would be affected in tryptophan-treated rats. Present study provide the clear-cut evidence that chronic treatment of apomorphine arouses the motor behavior of animals in both novel and anxiolytic model over the saline treated animals, whereas hypo locomotive behavior was seen in animals pre-treated with tryptophan, provides the evidence that preliminary treatment of tryptophan perturbs the apomorphine induced sensitization in animals. The discoveries present an inventive methodology for amplifying the remedial utilization of apomorphine and traditional psychostimulants.