Okumura K, Iwakawa S, Inui K, Hori R
Biochem Pharmacol. 1983 Sep 15;32(18):2689-95. doi: 10.1016/0006-2952(83)90077-1.
The dynamic nature of specific secretin binding sites in the pancreas was studied to simulate the interaction of secretin with its receptors in living organisms using isolated perfused rat pancreas. [125I]Secretin or [125I]-[Tyr1] secretin bound to certain binding sites in the perfused pancreas was displaced only by secretin in a dose-dependent manner, not by glucagon or vasoactive intestinal peptide, and the majority of the displaced radioactivity was demonstrated to be undegraded. On the basis of a secretin binding study with subcellular components, it was considered that the displacement would occur on the plasma membranes. These findings suggest that secretin which is distributed in the pancreas may rapidly and reversibly bind to specific binding sites or receptors on the plasma membranes with high affinity.
利用离体灌流大鼠胰腺，研究胰腺中特异性促胰液素结合位点的动态性质，以模拟促胰液素在活生物体中与其受体的相互作用。灌注胰腺中与某些结合位点结合的[125I]促胰液素或[125I]-[Tyr1]促胰液素仅被促胰液素以剂量依赖方式取代，而非胰高血糖素或血管活性肠肽，并且被取代的放射性大部分未被降解。基于对亚细胞成分的促胰液素结合研究，认为这种取代会发生在质膜上。这些发现表明，分布在胰腺中的促胰液素可能以高亲和力快速且可逆地与质膜上的特异性结合位点或受体结合。
