论文部分内容阅读
目的：研究低分化胃癌细胞株MKN－45细胞膜上的垂体腺苷环化酶激活肽（PACAP）受体及其特性。方法：用125I-PACAP-27对MKN－45细胞膜上的PACAP受体进行放射受体分析。结果：Scatchard分析结果表明MKN-45细胞膜上存在PACAP-27单位点结合受体，其解高常数（Kd）＝24．34nmol／L±2．85nmol／L，最大结合能力（Bmax）＝419．52pmol／106 细胞±7．25pmol／106细胞，PACAP－27的50％抑制浓度（IC50）＝24．24nmo／L。PACAP-38和血管活性肠肽（VIP）均可竞争125I－PACAP-27与PACAP-27受体的结合，PACAP－38（IC50＝67．97nmol／L）对受体的亲和力与PACAP－27相似，VIP对受体的亲和力较弱（IC50＝239．74nmol／L）。结论：MKN－45胃癌细胞膜上存在PACAP功能受体，提示PACAP可能对胃癌细胞的生长起一定作用。
PURPOSE: To study the expression of pituitary adenylate cyclase-activating peptide (PACAP) receptor on the membrane of poorly differentiated gastric cancer cell line MKN-45 and its characteristics. Methods: Radioimmunoassay of PACAP receptor on MKN-45 cell membrane was performed with 125I-PACAP-27. Results: The results of Scatchard analysis showed that PACAP-27 single site binding receptors existed on the membrane of MKN-45 cells. The Kd = 24.34nmol / L ± 2.85nmol / L and the maximum binding capacity (Bmax) = 419. 52 pmol / 106 cells ± 7.25 pmol / 106 cells, and the 50% inhibitory concentration (IC50) of PACAP-27 = 24.24 nmo / L. Both PACAP-38 and vasoactive intestinal peptide (VIP) compete for the binding of 125I-PACAP-27 to PACAP-27 receptor. PACAP-38 (IC50 = 67.97nmol / L) has similar affinity to the receptor as PACAP-27 , VIP affinity for the receptor is weak (IC50 = 239.74nmol / L). Conclusion: The presence of PACAP receptor on MKN-45 gastric cancer cell membrane suggests that PACAP may play a role in the growth of gastric cancer cells.