Maton P N, Pradhan T, Zhou Z C, Gardner J D, Jensen R T
Digestive Diseases Branch, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
Peptides. 1990 May-Jun;11(3):485-9. doi: 10.1016/0196-9781(90)90047-9.
In guinea pig pancreatic acini rat calcitonin gene-related peptide (CGRP) increased amylase release 2-fold, salmon calcitonin had an efficacy of only 44% of that of CGRP and [Tyr0]CGRP(28-37) and human calcitonin had no actions. [Tyr0]CGRP(28-37), but not human calcitonin, antagonized the actions of CGRP in pancreatic acini with an IC50 of 3 microM. [Tyr0]CGRP(28-37) produced a parallel rightward shift in the dose-response curve for CGRP-stimulated amylase secretion. The inhibition was specific for CGRP and was reversible. Studies with 125I-CGRP demonstrated that CGRP, salmon calcitonin and [Tyr0]CGRP, but not human calcitonin, interacted with CGRP receptors on pancreatic acini. These results indicate that various CGRP-related peptides demonstrate different relationships between their abilities to occupy the CGRP receptor and to affect biologic activity, with CGRP itself being a full agonist, salmon calcitonin a partial agonist, [Tyr0]CGRP(28-37) a competitive antagonist, and human calcitonin having no actions.
在豚鼠胰腺腺泡中，大鼠降钙素基因相关肽（CGRP）使淀粉酶释放增加了2倍，鲑鱼降钙素的效力仅为CGRP的44%，而[酪氨酰0]CGRP(28 - 37)和人降钙素则无作用。[酪氨酰0]CGRP(28 - 37)而非人降钙素，能拮抗CGRP在胰腺腺泡中的作用，其半数抑制浓度（IC50）为3微摩尔。[酪氨酰0]CGRP(28 - 37)使CGRP刺激的淀粉酶分泌的剂量反应曲线平行右移。该抑制作用对CGRP具有特异性且可逆。用125I - CGRP进行的研究表明，CGRP、鲑鱼降钙素和[酪氨酰0]CGRP能与胰腺腺泡上的CGRP受体相互作用，而人降钙素则不能。这些结果表明，各种与CGRP相关的肽在占据CGRP受体的能力和影响生物活性之间表现出不同的关系，其中CGRP本身是完全激动剂，鲑鱼降钙素是部分激动剂，[酪氨酰0]CGRP(28 - 37)是竞争性拮抗剂，而人降钙素无作用。
