【摘要】 目的 :比较兔不同动脉对多巴胺 1(DA1)受体激动剂和多巴胺 2 (DA2 )受体激动剂舒张的效应 ,分析不同血管床多巴胺受体的生理特性。方法 :利用DA1受体激动剂FODA(Fenoldopam)和DA2 受体激动剂PBDA及其拮抗剂 ,测定离体血管环舒张反应的大小。结果 :①DA1受体激动剂FODA引起的舒张血管效应以肾、肠血管为最强 ,而肺血管较弱、股血管则基本无反应 ;②DA2 受体激动剂PBDA的舒血管效应则以股、肠动脉血管为最强 ,肾和肺血管仅有轻度反应 ;③FODA的舒血管效应除肺血管外 ,均无内皮依赖性 ;④用 6 羟多巴胺 (6 OHDA)处理的兔进一步证实在一些血管存在DA2 受体。结论 :尽管上述 4种血管床均存在有DA受体 ,但是不同血管多巴胺受体的亚型类别与反应特性存在有明显不同。更多还原

【Abstract】 Aim:To study the subtypes and functional significance of dopamine (DA)receptors in different rabbit arteries in vitro.Methods:Responses of preconstricted vascular rings to selective DA receptor agonists and antagonists were examined.Results:①The efficacy and potency of fenoldopam in inducing relaxation varied comsiderably with different vessels.The relexation responses of renal and mesenteric arteries were most the potent to fenoldopam,but the pulmonary artery was weaky responded to fenoldopam,femoral artery showed no response to fenoldopam.②PBDA induced concentration dependent relaxations in all the vessels studied.However,anong the four vessels the mes enteric and femoral arteries showed most potent relexations to PBDA;renal and pulmonary arteries showed weak responses to PBDA.③Among the vessels studied,only pulmonary artery showed endothelium dependent relaxing response to DA agonists;and ④the existence of DA 2 receptors in mesenteric and femoral arteries was further evidenced in 6 OHDA treated rabbits.Conclusions:DA receptors subtypes are distributed in different vascular beds.To clarify the heterogeneity in subtype and responsiveness of DA receptors in the peripheral circulation may help to evaluate the physiological significance of DA receptors in the four vascular beds.更多还原