Goldberg L I, Toda N
Circ Res. 1975 Jun;36(6 Suppl 1):97-102. doi: 10.1161/01.res.36.6.97.
The purpose of this investigation was to develop a system for studying the effects of dopamine on isolated blood vessels. Canine renal, mesenteric, and small femoral arteries (less than 1 mm outside diameter) were exposed to phenoxybenzamine 10-5 M for one hour and contracted with prostaglandin F2-alpha. Cumulative concentrations of dopamine ranging from 10-6 to 10-4 M caused dose-related relaxation of the arteries. Propranolol 10-6 M did not affect the relaxation in concentrations which markedly antagonized the effects of isoproterenol. Large femoral arteries (greater than 1 mm outside diameter) did not relax with similar concentrations of dopamine. N-methyldopamine (epinine) produced similar relaxation; 3-methoxytyramine was inactive. Specific antagonism could not be demonstrated by the postulated dopamine antagonists-haloperidol, chlorpromazine, apomorphine, or bulbocapnine-in concentrations up to 10-5 M. Higher concentration of these agents could not be used because they caused the arteries to relax. This study demonstrated that PGF2-alpha-contracted arteries pretreated with phenoxybenzamine are suitable for further investigations of putative dopamine agonists and antagonists.
本研究的目的是开发一种用于研究多巴胺对离体血管作用的系统。将犬肾动脉、肠系膜动脉和股小动脉（外径小于1毫米）暴露于10^-5 M的酚苄明中1小时，并用前列腺素F2-α使其收缩。多巴胺的累积浓度范围为10^-6至10^-4 M，可引起动脉的剂量相关性舒张。10^-6 M的普萘洛尔在明显拮抗异丙肾上腺素作用的浓度下不影响舒张。外径大于1毫米的股大动脉对类似浓度的多巴胺不产生舒张反应。N-甲基多巴胺（去甲变肾上腺素）产生类似的舒张作用；3-甲氧基酪胺无活性。在高达10^-5 M的浓度下，假定的多巴胺拮抗剂——氟哌啶醇、氯丙嗪、阿扑吗啡或紫堇灵——无法显示出特异性拮抗作用。由于这些药物会导致动脉舒张，因此无法使用更高的浓度。本研究表明，用酚苄明预处理的PGF2-α收缩动脉适用于进一步研究假定的多巴胺激动剂和拮抗剂。
