Lim D K, Lee K M, Ho I K
College of Pharmacy, Chonnam National University, Kwang-Ju, Korea.
Arch Pharm Res. 1994 Dec;17(6):398-404. doi: 10.1007/BF02979114.
The behavioral response, dopamine metabolism, and characteristics of dopamine subtypes after developing the hyperglycemia were studied in the striata of rats. In animals developed hyperglycemia, the on-set and duration of cataleptic behavior responded to SCH 23390 injection was delayed and shortened, respectively. However, the cataleptic responses to spiperone occurred significantly earlier in on-set and prolonged in duration. Dopamine metabolites, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were significantly reduced in the striata of hyperglycemic rats. However, level of DA was significantly increased. It is noted that the ratios of DOPAC and HVA to DA were decreased, suggesting decreased turnover of DA. The affinity of striatal D-1 receptors was significantly increased without changes in the number of binding sites, while the maximum binding number of D-2 receptors was significantly increased without affecting its affinity in the diabetic rats. These results indicate that the dopaminergic activity in the striata was altered in hyperglycemic rats. Furthermore, it suggests that the upregulation of dopamine receptors might be due to the decreased dopamine metabolism.
在大鼠纹状体中研究了高血糖形成后其行为反应、多巴胺代谢及多巴胺亚型特征。在发生高血糖的动物中，对SCH 23390注射的僵住行为的起始和持续时间分别延迟和缩短。然而，对螺哌隆的僵住反应在起始时显著提前且持续时间延长。多巴胺代谢产物二羟基苯乙酸（DOPAC）和高香草酸（HVA）在高血糖大鼠纹状体中显著降低。然而，多巴胺水平显著升高。值得注意的是，DOPAC和HVA与多巴胺的比值降低，表明多巴胺周转率降低。纹状体D-1受体的亲和力显著增加，而结合位点数量无变化，同时在糖尿病大鼠中D-2受体的最大结合数显著增加，而不影响其亲和力。这些结果表明高血糖大鼠纹状体中的多巴胺能活性发生了改变。此外，这表明多巴胺受体的上调可能是由于多巴胺代谢降低所致。
