摘要
目的考察人结直肠肿瘤细胞株DLD - 1上甘氨酸延伸型胃泌素受体的结合特性 ;与CCK -A和CCK -B比较 ,找出不同之处。 方法 12 5Ⅰ标记甘氨酸延伸型胃泌素 ,反相高压液相纯化。用DLD - 1细胞进行受体结合试验 ,检测甘氨酸延伸型胃泌素受体结合试验受金属离子K+、Mg2 +、Al3+及温育温度、时间的影响 ;拮抗剂竞争抑制试验比较各种拮抗剂的作用。 结果金属离子K+、Mg2 +能提高甘氨酸延伸型胃泌素受体的特异结合 ,以10 0mmol/LTrisHCl缓冲液中含 10 0mmol/LK+,2mmol/LMg2 +为最佳 ;缓冲液含二个蛋白酶抑制剂时的最大结合发生在 37℃温育 90min ;没有蛋白酶抑制剂的最大结合发生在 37℃温育 6 0min。甘氨酸延伸型胃泌素受体的结合不被特异性CCK -A受体拮抗剂或特异性CCK -B受体拮抗剂拮抗 ,能被非特异性胃泌素受体拮抗剂benzotript拮抗。结论甘氨酸延伸型胃泌素受体的结合特性不同于CCK -A或CCK -B受体。DLD - 1细胞上的甘氨酸延伸型胃泌素受体既能与甘氨酸延伸型胃泌素结合 ,也能与酰胺化胃泌素结合 ,是一个不同于CCK -A和CCK
Objective To investigate the characteristics of binding of the glycine-extended gastrin receptor on human colorectal cancer cell line DLD-1 and the differences between CCK-A and CCK-B. Methods Glycine-extended gastrin was labeled with 125 Ⅰ and purified by reverse-phase high performance liquid chromatography. Binding assay on DLD-1 cells was set up, and the effects by K +、Mg 2+ 、Al 3+ as well as time and temperature of incubation were tested. The effects of several antagonists were also examined. Results The binding to the glycine-extended gastrin receptor was improved by K + and Mg 2+ in the range of their effective concentrations, especially 100mmol/L K + and 2mmol/L Mg 2+ in 100mmol/L Tris HCl buffer being the best. The optimal incubation was at 37℃ 90min with two protease inhibitors, or 37℃ 60min without protease inhibitors. The binding to the glycine-extended gastrin receptor was not inhibited by specific CCK-A antagonist or specific CCK-B antagonist, but inhibited by nonspecific antagonist benzotript. Conclusion The glycine_extended gastrin receptor has its own characteristics different from CCK-A or CCK-B and binds to both glycine-extended gastrin and amidated gastrin.
出处
《上海第二医科大学学报》
CSCD
2001年第4期300-302,共3页
Acta Universitatis Medicinalis Secondae Shanghai
基金
AustinHospitalMedicalResearchFoundation (Australia)
关键词
结直肠肿瘤
结肠肿瘤
直肠肿瘤
甘氨酸延伸型胃泌素受体
colorectal cancer
glycine-extended gastrin receptor
specific CCK-A antagonist
specific CCK-B antagonist
