培高利特对黑质多巴胺神经元放电活动的激动作用(英文)

Agonistic actions of pergolide on firing activity of dopamine neurons in substantia nigra compacta area

目的:研究D_2受体激动剂培高利特(pergolide,Per)对大鼠黑质多巴胺(DA)神经元放电活动的影响,并与溴隐亭(bromocriptine,Bro)作比较,同时验证Per在整体动物有无D_1激动剂性质.方法:胞外单细胞电活动记录技术. 结果:二个药物均能抑制敏感及不敏感的DA神经元自发放电活动.Per的ID_(50)值为11.9μg kg^-1),而Bro为7.8 mg kg^(-1),Per比后者强很多.选择性D_2受体拮抗剂螺哌隆(spiperone,0.25 mg kg^(-1))或者选择性D_1受体拮抗剂Sch-23390(1—2 mg kg^(-1))可以减弱放电抑制.然而Bro引起的放电抑制并不都能为spiperone所减弱.结论:Per在整体动物有很强的D_2受体激动剂作用,比Bro强650倍.也有弱的D_1受体激动剂的性质.

AIM:To study the potency of pergolide as a D2 receptor agonist on the firing activity of substantia nigra compacta (SNC) dopamine (DA) neurons compared with that of bromocriptine and to determine whether pergolide has the nature of D1 receptor agonist in vivo. METHODS: Extracellular single unit recording techniques. RESULTS: Both pergolide and bromocriptine decreased the spontaneously firing rate of 'sensitive' and 'insensitive' DA cells. In regard of ID50 values, pergolide (11.9, 95 % fiducial limits, 5.7 -25. 1ug kg-1) was more potent than bromocriptine (7.8, 95 % fiducial limits, 3.3 -18.5 mg kg-1). The discharge inhibition of pergolide was attenuated following the injection of selective D2 receptor antagonist spiperone 0. 25 mg kg-1 or selective D1 receptor antagonist Sch-23390 1 - 2 mg kg-1. However, the inhibition caused by bromocriptine was not always attenuated by spiperone. CONCLUSION: Pergolide is 650 times more potent than bromocriptine at D2 receptors, and possesses D1 receptor agonist characteristics invivo.