Hu G, Jin G Z
Shanghai Institute of Materia Medica, Chinese Academy of Sciences.
Zhongguo Yao Li Xue Bao. 1995 Jul;16(4):376-9.
To evaluate the action of (-)-stepholidine (SPD), a novel dopamine (DA) receptor antagonist, on inhibition by presynaptic D2 receptor agonists on the activity of synaptosomal tyrosine hydroxylase (TH) in the striatum.
The TH activity was measured by HPLC-ECD.
The mixed DA receptor agonist apomorphine (Apo 10.4 nmol L-1) and selective D2 receptor agonists N-0437 (0.4 pmol L-1) and quinpirole (0.8 mumol L-1) inhibited the activity of TH, while selective D1 receptor agonist SKF 38393 (0.001-10 mumol L-1) and SPD (1-100 mumol L-1) failed to inhibit the TH activity. The inhibition of N-0437 and quinpirole were antagonized by D2 receptor antagonist spiperone and SPD.
The negative feedback regulation of presynaptic DA receptors is mediated via D2 receptors and SPD is an antagonist on presynaptic D2 DA receptors.
评估新型多巴胺（DA）受体拮抗剂（-）-千金藤啶碱（SPD）对突触前D2受体激动剂抑制纹状体突触体酪氨酸羟化酶（TH）活性的作用。
采用高效液相色谱-电化学检测法测定TH活性。
混合DA受体激动剂阿扑吗啡（Apo 10.4 nmol L-1）以及选择性D2受体激动剂N-0437（0.4 pmol L-1）和喹吡罗（0.8 μmol L-1）抑制TH活性，而选择性D1受体激动剂SKF 38393（0.001 - 10 μmol L-1）和SPD（1 - 100 μmol L-1）未能抑制TH活性。N-0437和喹吡罗的抑制作用被D2受体拮抗剂螺哌隆和SPD拮抗。
突触前DA受体的负反馈调节通过D2受体介导，且SPD是突触前D2 DA受体的拮抗剂。
