Cao J, Chen M, Wang Q
Institute of Basic Medical Sciences, CAMS, Beijing.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 1996 Aug;18(4):279-83.
A comparative study was made on the distribution of alpha- and beta-adrenoceptors between rat basilar (BA) and renal arteries (RA). The results showed that (1) the endothelium-independent relaxation due to beta-agonism was more significant in BA than that in RA; (2) there was no alpha 1-adrenoceptor-mediated vasoconstriction in most of the BA, only a small part of BA showed constriction in response to alpha 1-agonism, but with low affinity and efficacy and a desensitization tendency; (3) no response to alpha 2-agonist BHT 920 (10(-3) mol/L) in BA was shown, either in the presence or absence of endothelium. But in RA there was relaxation in the presence of endothelium and constriction in its absence. The above results suggest that there is a scarce distribution of alpha 1- and alpha 2-adrenoceptors, but an abundant distribution of beta-adrenoceptor in basilar artery compared with that in renal artery. The alpha 1-subtype in BA is different from the alpha 1-subtype in RA, and the alpha 2-receptor which mediates direct smooth muscle constriction and endothelium-dependent relaxation is highly heterogeneous between basilar and renal arteries.
对大鼠基底动脉（BA）和肾动脉（RA）之间α-和β-肾上腺素能受体的分布进行了一项比较研究。结果表明：（1）β激动剂引起的内皮依赖性舒张在BA中比在RA中更显著；（2）大多数BA中不存在α1-肾上腺素能受体介导的血管收缩，只有一小部分BA对α1激动剂有收缩反应，但亲和力和效能低且有脱敏倾向；（3）在有无内皮的情况下，BA对α2激动剂BHT 920（10^(-3)mol/L）均无反应。但在RA中，有内皮时出现舒张，无内皮时出现收缩。上述结果表明，与肾动脉相比，基底动脉中α1和α2肾上腺素能受体分布稀少，但β肾上腺素能受体分布丰富。BA中的α1亚型与RA中的α1亚型不同，介导直接平滑肌收缩和内皮依赖性舒张的α2受体在基底动脉和肾动脉之间高度异质。
