α 2c肾上腺素受体调节人右心房去甲肾上腺素的释放。

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Rump LC, Bohmann C, Schaible U, Schollhorn J, Limberger N

α 2c肾上腺素受体调节人右心房去甲肾上腺素的释放。

中国药物学杂志，1995 11月;116(6):2617-24。

PubMed ID

8590979 (PubMed视图

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摘要

1.本研究的目的是根据α 2A-D系统来表征人类右心房的突触前α 2-自受体。用[3H]-去甲肾上腺素预培养心房附耳片段，然后在可卡因存在下再灌注并电刺激。测定了8种具有鉴别力的α -肾上腺素受体拮抗剂的pEC30%值。pEC30%是使刺激诱导的氚溢出增加30%的拮抗剂浓度的负对数。对于四种拮抗剂，在无自抑制条件下，除pEC30%外，还测定了解离常数KD对5-溴-6-(2-咪唑啉-2-基氨基)-quinoxaline (UK 14304)溢出抑制作用的影响。2.pEC30%和KD值产生了相同的拮抗剂亲和力(rauwolscine > WB 4101 > phentolamine > prazosin)，表明释放的去甲肾上腺素和外源激动剂UK 14304都激活了相同的受体抑制释放。3.在人类肾脏突触前α 2c自受体中，右心房获得的8种拮抗剂pEC30%值与文献报道的pEC30%值显著相关(r = 0.817; slope of the regression line 1.03). No significant correlation was obtained between pEC30% values at atrial autoreceptors and pKD values at previously characterized alpha 2A-autoreceptors in rabbit and alpha 2D-autoreceptors in rat, mouse and guinea-pig tissues. 4. Comparison of antagonist pEC30% values with their pKD values at native alpha 2 binding sites in cells or tissues that express a single subtype only, and with pKD values at alpha 2 binding sites in membranes of COS cells transfected with human alpha 2 subtype genes confirms the alpha 2C character of the atrial autoreceptors: significant correlations were obtained exclusively with the alpha 2C binding sites. 5. Ratios of KD values were computed for alpha 2-autoreceptors in human right atrium and for binding sites in COS cells transfected with human alpha 2 subtype genes. The autoreceptor ratios corresponded well with the respective ratios for the alpha 2C binding sites (maximal three fold deviation) but were, in part, markedly different from ratios calculated for alpha 2A and alpha 2B binding sites (up to 166 fold deviation). This outcome supports the alpha 2C designation of the autoreceptors. 6. In conclusion, the presynaptic alpha 2-autoreceptors in human right atrium are alpha 2C. In this they agree with the previously characterized alpha 2-autoreceptors in human kidney. The alpha 2C classification possibly separates, in general, human alpha 2-autoreceptors from those in lagomorph (rabbit) and rodent (rat, mouse, guinea pig) species that have been proposed to be predominantly alpha 2A or alpha 2D.

引用本文的药物库数据

药物靶点

药物	目标	种类	生物	药理作用	行动
Droxidopa	α - 2c肾上腺素能受体	蛋白质	人类	是的	受体激动剂	细节
去甲肾上腺素	α - 2c肾上腺素能受体	蛋白质	人类	是的	受体激动剂	细节