ABSTRACT
AIM: To observe the effects of different doses of L-dopa on the rotational behavior and amounts of cells expressing D_2 receptors in striatum in hemiparkinsonian rats.METHODS: A hemiparkinsonian model was established in rats by pretreatment with 6-hydroxydopamine.The D_2 receptor expression were detected by immunohistochemical staining.The numbers of rotations induced by apomorphine was counted within 30 min before and after L-dopa(10 mg?kg~(-1)?d~(-1),50 mg?kg~(-1)?d~(-1) or 100 mg?kg~(-1)?d~(-1),ip) was introduced to Parkinson's disease(PD) model rats for 15 days.RESULTS: In successful PD model rats,the increased percentage of D_2 receptor in lesioned side compared with intact side was associated linearly with the numbers of rotations within 30 min(r=0.927,P