Stephenson J A, Summers R J
Eur J Pharmacol. 1985 Oct 22;116(3):271-8. doi: 10.1016/0014-2999(85)90162-1.
The localization of [3H]rauwolscine binding to microscope slide mounted sections of rat kidney has been examined using the technique of in vitro labelling and autoradiography. Binding to sections equilibrated within 60 min and was reversible following the addition of 10 microM phentolamine. Saturation studies revealed a single population of high affinity (KD 4.27 nM) non-interacting sites (nH 0.97) with a density of 11.1 fmol/section. Stereoselectivity was observed with respect to the isomers of noradrenaline and the relative affinity of a series of alpha-adrenoceptor antagonists suggested binding to alpha 2-adrenoceptors. Autoradiographic studies using 3H-Ultrofilm showed that the binding is largely confined to the renal cortex. More detailed studies using emulsion coated coverslips indicates that the major concentration of binding sites is over the proximal tubules. This study provides evidence that alpha 2-adrenoceptors, known to be coupled in an inhibitory fashion to renal adenylate cyclase, are highly localized to particular structures in the kidney.
采用体外标记和放射自显影技术，研究了[3H]萝芙辛与大鼠肾脏显微镜载玻片切片的结合定位。与在60分钟内平衡的切片结合，加入10微摩尔酚妥拉明后结合是可逆的。饱和研究显示存在一群高亲和力（KD 4.27纳摩尔）的非相互作用位点（nH 0.97），密度为11.1飞摩尔/切片。观察到对去甲肾上腺素异构体的立体选择性，一系列α-肾上腺素能拮抗剂的相对亲和力表明其与α2-肾上腺素能受体结合。使用3H-Ultrofilm进行的放射自显影研究表明，结合主要局限于肾皮质。使用乳胶包被盖玻片的更详细研究表明，结合位点的主要集中在近端小管上。本研究提供了证据，已知以抑制方式与肾腺苷酸环化酶偶联的α2-肾上腺素能受体高度定位于肾脏的特定结构。
