Cholecystokinin and gastrin peptides stimulate ODC activity in a rat pancreatic cell line.
Cholecystokinin and gastrin peptides stimulate ODC activity in a rat pancreatic cell line.
复制标题
胆囊收缩素和胃泌素肽刺激大鼠胰腺细胞系中的 ODC 活性。
DOI：
10.1152/ajpgi.1989.256.5.g846
复制
发表时间：
1989
期刊：
影响因子：
--
通讯作者：
N. Vaysse
中科院分区：
文献类型：
--
作者：
J. Scemama;L. de Vries;L. Pradayrol;C. Seva;H. Tronchère;N. Vaysse
最近的研究表明，胆囊收缩素（CCK）受体在外周组织和中枢神经系统中是异源的，并且CCK-胃泌素（CCK-G）肽是胃肠道的有效营养因子。在本研究中，我们使用125 I标记的胃泌素和125 I标记的CCK证明CCK受体的异质性大鼠胰腺腺泡细胞系（AR 4 - 2 J），并分析这些受体的作用，在增加鸟氨酸脱羧酶的活性。放射性配体结合的药理学分析与两种不同受体的存在很好地吻合：1）具有正常胰腺细胞上存在的CCK受体特征的CCK选择性受体和2）与所有硫酸化和非硫酸化CCK-G肽相互作用的高亲和力、低选择性CCK-G结合位点。CCK-G肽刺激鸟氨酸脱羧酶活性的效力顺序（EC 50）如下：G-（2-17）-ds（0.1 nM）大于或等于CCK-9（0.25 nM）大于或等于五肽胃泌素（0.4 nM）大于CCK-4（6 nM）。在阻断CCK受体的浓度范围内，这种刺激不受CCK拮抗剂（曲霉素）的抑制，但不与125 I标记的胃泌素竞争结合CCK-G受体。用CCK-G激动剂和拮抗剂获得的这些结果表明，这些细胞中的鸟氨酸脱羧酶刺激通过CCK-G受体介导。
Recent studies have demonstrated that cholecystokinin (CCK) receptors are heterologous in peripheral tissues and in the central nervous system and that CCK-gastrin (CCK-G) peptides are potent trophic factors for the gastrointestinal tract. In the present study we used 125I-labeled gastrin and 125I-labeled CCK to demonstrate the heterogeneity of CCK receptors on a rat pancreatic acinar cell line (AR4-2J) and analyze the role of these receptors in increasing the activity of ornithine decarboxylase. Pharmacological analysis of radioligand binding fit well with the presence of two different receptors: 1) a CCK-selective receptor having the characteristics of the CCK receptor present on normal pancreatic cells and 2) a high-affinity, low-selectivity CCK-G binding site that interacts with all CCK-G peptides sulfated and nonsulfated. CCK-G peptides stimulate ornithine decarboxylase activity with the following order of potencies (EC50): G-(2-17)-ds (0.1 nM) greater than or equal to CCK-9 (0.25 nM) greater than or equal to pentagastrin (0.4 nM) greater than CCK-4 (6 nM). This stimulation was not inhibited by CCK antagonist (asperlicin) at a concentration range that blocks the CCK receptor but does not compete with 125I-labeled gastrin binding to the CCK-G receptor. These results, obtained with CCK-G agonists and antagonists, demonstrate that ornithine decarboxylase stimulation in these cells is mediated via the CCK-G receptor.