Schmidt M, Giesen-Crouse E, Imbs J L
Naunyn Schmiedebergs Arch Pharmacol. 1987 Apr;335(4):378-84. doi: 10.1007/BF00165551.
The renal and iliac vascular effects of dopamine were compared in pentobarbital anaesthetized rats. Local vascular resistances were calculated from simultaneous measurement of blood pressure, renal and iliac blood flow. Without pretreatment, dopamine increased renal and iliac vascular resistance. After pretreatment with prazosin, dopamine decreased the renal vascular resistance while the iliac vascular resistance was still increased. After a combination of yohimbine and prazosin pretreatment, dopamine lowered both the renal and iliac vascular resistance by 30%. These responses were not modified by the beta-adrenoceptor antagonist, sotalol, or by pretreating the rats with reserpine. The renal but not the iliac vascular response to dopamine was abolished by (+)-butaclamol, a stereoselective dopamine receptor antagonist, and by SCH 23390, the DA1-selective dopamine receptor antagonist. The decrease in iliac vascular resistance was not modified by indomethacin or the non-selective 5-HT receptor antagonist, metitepin. These results show that after blockade of alpha 1 and alpha 2-adrenoceptors, dopamine induces iliac vasodilation by a postsynaptic mechanism independent of an interaction with beta-adrenoceptors, dopamine or serotonin receptors. They also confirm in the rat in vivo the existence of renal vasodilation mediated by DA1 dopamine receptors.
在戊巴比妥麻醉的大鼠中比较了多巴胺对肾和髂血管的作用。通过同时测量血压、肾血流量和髂血流量来计算局部血管阻力。未进行预处理时，多巴胺会增加肾和髂血管阻力。用哌唑嗪预处理后，多巴胺降低了肾血管阻力，而髂血管阻力仍增加。在用育亨宾和哌唑嗪联合预处理后，多巴胺使肾和髂血管阻力均降低了30%。这些反应不受β-肾上腺素能受体拮抗剂索他洛尔的影响，也不受利血平预处理大鼠的影响。（+）-布他拉莫（一种立体选择性多巴胺受体拮抗剂）和DA1选择性多巴胺受体拮抗剂SCH 23390消除了多巴胺对肾血管的反应，但未消除对髂血管的反应。吲哚美辛或非选择性5-羟色胺受体拮抗剂美替平未改变髂血管阻力的降低。这些结果表明，在阻断α1和α2肾上腺素能受体后，多巴胺通过一种与β-肾上腺素能受体、多巴胺或5-羟色胺受体相互作用无关的突触后机制诱导髂血管舒张。它们还在大鼠体内证实了由DA1多巴胺受体介导的肾血管舒张的存在。
