β-肾上腺能受体配基^(125)碘氰心得静的标记和鉴定

The Labelling and Identification of ~125Iodocyanopindolol, A Ligand For Beta Adrenoceptors

由于进口昂贵,我们自行标记β受体放射性配基^(125)ICYP,并与进口Amersham产品作比较。结果表明两者的比活性、放射化学纯度(％),游离碘百分比均接近。自标^(125)ICYP测得大鼠肺组织β受体Bmax为662.5fmol/mg蛋白,Kd为1.47nM,进口产品测得的为Bmax603.9fmol/mg蛋白,Kd为1.83nM。两者数值接近,与文献资料也相似。薄板层析结果表明层析后^(125)ICYP显示的园点位置一致。放射自显影结果表明所得肺组织β受体图像中,各种结构分布特点也相同,肺实质最多,气道的β受体又多于血管。说明自标的^(125)ICYP可用于受体研究,特别作为放射自显影,曝光3～5天即可得清晰的β受体分布图像,与~3H标记配体相比,大大缩短了实验周期。

The ligand 125ICYP labelled by our laboratory,was compared with the Amer sham product. It was found that they are similar purity, radiospecific activity, percentage of free iodine and binding characteristics. Beta adrenocep-tors in the homogenates of rat lung (Bmax and Kd) estimated by these two products were similar.Autoradiography results showed typical beta adrenocep-tor distribution. Highest density was found in parenchyma. Bronchioles showed a higher density than the pulmonary blood vessels. Results showed that the self-labelled ligand 125ICYP is qualified for binding experiment of beta adrenoceptor, especially for the autoradiography.