SnCl2还原法生长抑素受体显像剂99Tcm-octreotide(奥曲肽)的生物活性研究

目的　检测SnCl2 还原法生长抑素受体显像剂99Tcm octreotide(奥曲肽 )的生物活性。方法　自制大鼠脑皮质细胞膜 ,进行99Tcm oc treotide与其受体特异性结合能力测定 (TB)、非特异性结合能力测定 (NBS)与竞争性抑制能力测定 ,判断SnCl2 还原法生长抑素受体显像剂99Tcm oc treotide的生物活性。结果　在大鼠脑细胞膜受体固定的条件下99Tcm octreotide与脑细胞膜受体的特异性结合量随99Tcm octreotide的增加而增加 ,但增加的幅度逐渐减低 ,呈饱和趋势 ;非特异性结合量随99Tcm octreotide的增加呈直线上升 ,无饱和趋势 ;竞争抑制实验结果显示 ,随着非标记99Tcm octreotide含量的逐渐增加 ,99Tcm octreotide与脑细胞膜的结合率逐渐降低。结论　本研究获得的99Tcm octreotide具有生长抑素类似物正常的生物学功能。

Biological activity detection of 99Tcm-Octreotide by SnCl2 deoxidization

Objective To detect biological activity of SSTR 99Tc m-Octreotide made by SnCl 2 deoxidization. Methods Choose cell membrane of mice brain cortex and evaluate biological acti vity of somatostatin receptor (SSTR) labeled by 99Tc m-Octreotide by tes ting specific binding ability (TB) of 99Tc m-Octreotide to its receptors and non-specific binding ability (NBS) and competitive inhibiting ability. Results Under stable conditions, the quantity of 99T c m-Octreotide binding specific brain membrane receptors enlarges as 99T c m-Octreotide increases with a trend of saturation. While the quantity of non -specific binding increased without the trend of saturation. Competitive inhibi ting tests demonstrated that the binding rate decreased as non-labeled Octreoti de increased. Conclusions 99Tc m-Octreotide obt ained in this research has certain biological characteristics similar to SSTR.