【摘要】 目的探讨直接法标记99mTc-octreotide的方法学及其与大鼠脑皮质细胞的亲和力。方法用直接法标记99mTc-octreotide,探讨其最佳标记条件;并以~99mTc-octreotide作为配基,检测大鼠脑皮质细胞与其结合的平衡解离常数。结果99mTc—octreotide标记率为53％～57％,经Sephadex G-10纯化后放化纯大于95％;受体分析显示大鼠脑皮质细胞与99mTc-octreotide保持了较高的亲和力(Kd=10.4nM)。结论 本标记方法是可行的,99mTc—octreotide有希望作为具有临床实用价值的生长抑素受体显像剂。更多还原

【Abstract】 Objective To establish the method of directly labeling octreotide with 99mTc, and explore the affection factors to its radiochemical purity, and the in vitro receptor binding affinity of 99mTc-oc-treotide. Method The octreotide was reduced using the ascorbic acid method, and 99mTc reduced with a fresh solution of Na2S2O4. The affection of temperature, pH of ascorbic acid and the buffer to radio-chemical purity was determined. The in vitro somatostatin receptor (SSTR)-binding affinity of 99mTc-octreotide purified by Sephadex G10, was confirmed by Scatchard analyses using SD rats brain cortex cell.Results 99mTc-octreotide were prepared in 53-57% radiochemical yield, after purified, radio-chemical purity >95% , and it has a Kd = 10.4 nM , and Bmax = 29. 4fmol/μg. Conclusion The method of directly labeling octreotide with 99mTc is available, and 99mTc-octreotide is a promising radiotracer for the clinical detection of SSTR-expressing tumor by radionuclide scintigraphy.更多还原