Kaakkola S, Wurtman R J
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139.
Brain Res Bull. 1993;32(6):667-72. doi: 10.1016/0361-9230(93)90171-7.
The effects of two diketopiperazines, Cyclo (His-Pro) (CHP) and Cyclo (Asp-Phe) (CAP), on striatal extracellular levels of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were examined using in vivo microdialysis in anaesthetized rats. Treatment with neither CHP (0.1-10 mg/kg IP and 0.3 mg/kg i.v.) nor CAP (0.1-10 mg/kg IP and 10 mg/kg PO) significantly changed the efflux of DA, DOPAC, HVA, or 5-HIAA when compared to the effects of treatment with saline. Our results suggest that systemic administration of CHP or CAP alone does not modify striatal dopaminergic neurotransmission. The previous findings of enhanced DA release by systemic administration of thyrotropin releasing hormone (TRH) are probably not explained by formation of CHP from TRH.
使用麻醉大鼠体内微透析技术，研究了两种二酮哌嗪，即环（组氨酸-脯氨酸）（CHP）和环（天冬氨酸-苯丙氨酸）（CAP）对纹状体细胞外多巴胺（DA）、二羟基苯乙酸（DOPAC）、高香草酸（HVA）和5-羟吲哚乙酸（5-HIAA）水平的影响。与生理盐水处理的效果相比，CHP（0.1-10mg/kg腹腔注射和0.3mg/kg静脉注射）和CAP（0.1-10mg/kg腹腔注射和10mg/kg口服）处理均未显著改变DA、DOPAC、HVA或5-HIAA的流出量。我们的结果表明，单独全身给药CHP或CAP不会改变纹状体多巴胺能神经传递。先前关于全身给药促甲状腺激素释放激素（TRH）可增强DA释放的发现，可能无法用TRH形成CHP来解释。
