title: Somatostatin receptors.
abstract: 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.
authors.forename: C B
authors.initials: CB
authors.lastname: Srikant
authors.forename: Y C
authors.initials: YC
authors.lastname: Patel
mesh_terms: D000302:Adrenal Cortex / Q000378:metabolism; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism; D006801:Humans; D010179:Pancreas / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017481:Receptors, Somatostatin; D013004:Somatostatin / Q000031:analogs & derivatives / Q000378:metabolism*; D053561:Somatostatin-28; D013329:Structure-Activity Relationship
chemical_list: D011956:Receptors, Cell Surface; D017481:Receptors, Somatostatin; D013004:Somatostatin; D053561:Somatostatin-28; C034801:somatostatin, iodo-Tyr(1)-