Srikant C B, Patel Y C
Adv Exp Med Biol. 1985;188:291-304. doi: 10.1007/978-1-4615-7886-4_16.
It is now well established that the biological actions of tetradecapeptide somatostatin (somatostatin-14, S-14) are receptor-mediated. These receptors were first quantified in GH4C pituitary tumor cells using [125I-Tyr1] S-14 as radioligand which was found to exhibit high non-specific binding to membrane receptor preparations from normal tissues. Our studies have shown that [125I-Tyr11] S-14 in which the radiolabel is situated away from the N-terminus exhibits significantly lower non-specific binding and therefore is more suitable for S-14 receptor studies. In the CNS, highest concentration of S-14 receptors was found in the cerebral cortex, followed by thalamus, hypothalamus, striatum, amygdala and hippocampus while medulla-pons, cerebellum and spinal cord exhibited negligible binding. Outside the CNS membrane receptors for S-14 have been characterized in pituitary, adrenal cortex and pancreatic acini. In all these tissues a single class of high affinity binding sites for S-14 were present, the receptors in pancreatic acinar cells exhibiting significantly greater affinity for binding S-14 than in other tissues.
现已明确，十四肽生长抑素（生长抑素 - 14，S - 14）的生物学作用是由受体介导的。这些受体最初是在GH4C垂体肿瘤细胞中使用[125I - Tyr1]S - 14作为放射性配体进行定量的，结果发现该配体与正常组织的膜受体制剂表现出高非特异性结合。我们的研究表明，放射性标记位于远离N端的[125I - Tyr11]S - 14表现出显著更低的非特异性结合，因此更适合用于S - 14受体研究。在中枢神经系统中，S - 14受体浓度最高的部位是大脑皮层，其次是丘脑、下丘脑、纹状体、杏仁核和海马体，而延髓 - 脑桥、小脑和脊髓的结合可忽略不计。在中枢神经系统之外，已在垂体、肾上腺皮质和胰腺腺泡中鉴定出S - 14的膜受体。在所有这些组织中，都存在一类单一的S - 14高亲和力结合位点，胰腺腺泡细胞中的受体对S - 14的结合亲和力明显高于其他组织。
