Korean Journal of Biological Psychiatry

The effects of chronic treatment with haloperidol and sulpiride on the binding capacities of dopamine(DA) receptor were examined in rat striatum and Olfactory tuberde. Additionally, the stereolypy scores were assessed after opamarphine administrotion. Rats were treated with holoperidol(0.5mg/kg/day) or sulpiride(40mg/kg/day) for four weeks. Apomorphine(0.5mg/kg) was injected after three-day washout from neuroleptics, and stereotypy scores were assessed. Holoperidol group, sulpiride group displayed similar sterectyped behaviors. Saturation analysis of the binding of [³H]spiperone to striatal membranes showed that the Bmax of holoperidol and sulpiride groups increased signilicantly in comparison with that of control group. The KD decreased signilcontly and sulpiride groups increased signilicantly in comparison with that of control group. The KD decreased signilcantly after sulpiride trectment in striatum. Although sulpiride produces the same prolferation of DA receptor, the low stereotypy scores of sulpiride group indirectly suggest that sulpiride acts differently from holoperdol in brain DA system. The Bmax increased remarkably following both treatment with holoperdol and sulpiride in olfactory tubercle. Moreover, the KD of control group in Olfactory tubercle was more than twice the KD of control group in Olfactory tubercle was more than twice the KD of control group in striatum. The KD was 86.2 in striatum and 37.5 pM in Olfactory tubercle. The present finding indicotes that sulpiride also induces the prolileration of DA receptor in Olfactory tubercle. The present finding indicates that sulpirde also induces the prolileration of DA receptor in Olfactory tubercle and may interoct with some DA receptor subtype with high affinity profile. The different affinifies of the control groups of striatum and Olfactory tubercle suggest that striatol DA receptor sublypes lobeled by [³H]spiperone could differ from those of Olfactory tubercle.

Keywords Haloperidol;Sulpiride;DA subtypes;Striatum;Olfactory tubercle;[³H]spoperone.