CCK-8及损毁MFB对腹侧被盖区和伏核多巴胺、CCK-8含量的影响

Effects of cholecystokinin octapeptide and lesion of the medial forebrain bundle on the contents of dopamine and CCK-8 from ventral tegmental area and nucleus accumbens

应用荧光分光光度法和放射免疫法 ,在以 6-羟基多巴胺 ( 6- OHDA)单侧损毁内侧前脑束 ( MFB)制备的偏侧帕金森病 ( PD)大鼠模型身上 ,测定了腹侧被盖区 ( VTA)和伏核 ( Acb)中多巴胺 ( DA)和八肽胆囊收缩素 ( CCK- 8)的含量 ,并观察了 VTA和 Acb区微量注射 CCK- 8对正常大鼠 DA含量的影响。结果如下 :PD大鼠模型损毁侧 VTA和 Acb的 DA和 CCK- 8的含量与健侧及对照组相比均减少 ( P<0 .0 1 ) ;而健侧 VTA和 Acb的 DA和 CCK- 8的含量同正常大鼠相比 ,差别无显著性 ( P>0 .0 5)。正常大鼠 Acb微量注射 CCK- 8能使 Acb的 DA含量增高 ( P<0 .0 5) ;而 VTA微量注射 CCK- 8则不影响 VTA和 Acb区的 DA含量 ( P>0 .0 5)。结果表明 ,6- OHDA单侧损毁 MFB后既降低中脑 DA能系统中 VTA和 Acb的 DA含量 ,又降低该系统中 VTA和 Acb区与 DA共存的 CCK- 8含量 ;并提示 Acb区外源性 CCK- 8可增加该区的 DA含量。

By means of fluorometry and radioimmunoassay, the brain contents of dopamine (DA) and cholecystokinin octapeptide (CCK 8) in the lesioned and contralateral normal sides of ventral tegmental area (VTA) and nucleus accumbens (Acb) in the rat model of Parkinson′s disease (PD) were measured, in which medial forebrain bundle (MFB) was lesioned unilaterally with 6 hydroxydopamine (6 OHDA), and the effects of CCK 8 microinjected into VTA or Acb were observed. The main findings were as follows: the contents of DA and CCK 8 in lesioned sides were less than that of unlesioned sides in the model of PD rats or the control groups ( P <0 01), while there was no significant difference between the unlesioned sides and control groups ( P >0 05). An increase in DA contents from Acb was found after CCK 8 microinjected into Acb ( P <0 05), but there was no significant change after CCK 8 injected into VTA ( P >0 05). The results suggest that MFB unilaterally lesion with 6 OHDA either decreased DA contents of VTA and Acb,or decreased CCK 8 contents which coexisted with DA of VTA and Acb in the mesolimbic DAergic system. The results also suggest that exogenous CCK 8 in Acb can increase the contents of DA from Acb.