牛睫状体中存在多巴胺D1受体的生化及功能证据。

Biochemical and functional evidence for the presence of dopamine D1 receptors in the bovine ciliary body.

作者信息

Lograno M D, Daniele E, Govoni S

机构信息

Department of Pharmacobiology, University of Bari, Italy.

出版信息

Exp Eye Res. 1990 Nov;51(5):495-501. doi: 10.1016/0014-4835(90)90079-a.

DOI:10.1016/0014-4835(90)90079-a

PMID:1979033

Abstract

The present paper reports both functional and biochemical evidence for the presence of dopamine D1 receptors in the bovine ciliary body. Dopamine (DA) and dopamine D1 agonists (such as SKF 38,393) but not D2 agonists (such as LY 141,865) produced a concentration-related decrease in the tone induced by a maximally active concentration of carbachol (1 x 10(-4)-5 x 10(-4) M). The maximal relaxation obtained was 100% of the carbachol response using 10(-5) M dopamine or 5 x 10(-6) M SKF 38,393. SCH 23,390, a D1 antagonist, but not (-)-sulpiride, antagonized the effect of DA and SKF 38,393. In accordance with the functional data, radioreceptor binding experiments revealed the existence of a high affinity saturable [3H]SCH 23,390 binding to membranes prepared from ciliary body (Bmax: 344 fmol mg protein-1; Kd: 0.87 nM). The binding was specifically displaced by SCH 23,390, dopamine and dopamine D1 agonists, but not by norepinephrine, D2 agonists, or antagonists such as LY 141,865 and sulpiride. No specific binding was found when using dopamine D2 ligands, such as tritiated spiroperidol.

摘要

本文报告了牛睫状体中存在多巴胺D1受体的功能和生化证据。多巴胺（DA）和多巴胺D1激动剂（如SKF 38,393），而非D2激动剂（如LY 141,865），可使卡巴胆碱最大活性浓度（1×10⁻⁴ - 5×10⁻⁴ M）诱导的张力呈浓度依赖性降低。使用10⁻⁵ M多巴胺或5×10⁻⁶ M SKF 38,393时，获得的最大舒张率为卡巴胆碱反应的100%。D1拮抗剂SCH 23,390可拮抗DA和SKF 38,393的作用，而（-）-舒必利则无此作用。与功能数据一致，放射受体结合实验显示存在一种高亲和力的可饱和[³H]SCH 23,390与睫状体制备的膜结合（Bmax：344 fmol mg蛋白⁻¹；Kd：0.87 nM）。该结合可被SCH 23,390、多巴胺和多巴胺D1激动剂特异性取代，但不能被去甲肾上腺素、D2激动剂或拮抗剂（如LY 141,865和舒必利）取代。使用多巴胺D2配体（如氚化螺哌啶）时未发现特异性结合。