Martin J R, Beinfeld M C, Wang R Y
Brain Res. 1986 Nov 12;397(2):253-8. doi: 10.1016/0006-8993(86)90626-8.
The effect of specific D-2 dopamine (DA) receptor agonists and antagonists on potassium (55 mM)-evoked release of cholecystokinin-like immunoreactivity (CCK-LI) was studied in tissue slices of the rat posterior nucleus accumbens (NAc). Incubating the tissue slices in 100 nM or 1 microM of LY-141865, a specific D-2 DA receptor agonist, reduced the release of CCK-LI as indicated by a significant decrease in the S2/S1 ratio. Addition of 10 microM of (-)-sulpiride, a specific D-2 DA receptor antagonist, blocked the inhibitory effect of 100 nM of LY-141865 on the release of CCK-LI. In contrast, 10 microM of the specific D-1 DA receptor antagonist SCH 23390 was unable to attenuate the decrease in release of CCK-LI caused by 100 nM of LY-141865. Furthermore, the active isomer of LY-141865, LY-171555 at 0.1 to 50 nM, also decreased the release of CCK-LI from the tissue slices, while the inactive isomer, LY-181990 at 1 nM, did not affect CCK-LI release. The inhibitory effect of LY-171555 on the release of CCK-LI was lost when its concentration was increased to 100 nM, thus revealing a biphasic effect of D-2 DA receptor stimulation on the release of CCK-LI. These results demonstrate that stimulation of D-2 DA receptor can modulate the release of CCK from in vitro slices of the rat posterior NAc.
在大鼠伏隔核后核（NAc）组织切片中，研究了特异性D-2多巴胺（DA）受体激动剂和拮抗剂对钾（55 mM）诱发的胆囊收缩素样免疫反应性（CCK-LI）释放的影响。将组织切片置于100 nM或1 μM的特异性D-2 DA受体激动剂LY-141865中孵育，如S2/S1比值显著降低所示，CCK-LI的释放减少。添加10 μM的特异性D-2 DA受体拮抗剂（-）-舒必利，可阻断100 nM LY-141865对CCK-LI释放的抑制作用。相比之下，10 μM的特异性D-1 DA受体拮抗剂SCH 23390无法减弱100 nM LY-141865引起的CCK-LI释放减少。此外，LY-141865的活性异构体LY-171555在0.1至50 nM时，也可减少组织切片中CCK-LI的释放，而无活性异构体LY-181990在1 nM时不影响CCK-LI的释放。当LY-171555的浓度增加到100 nM时，其对CCK-LI释放的抑制作用消失，从而揭示了D-2 DA受体刺激对CCK-LI释放的双相作用。这些结果表明，刺激D-2 DA受体可调节大鼠后NAc体外切片中CCK的释放。
