title: Somatostatin analogs inhibit somatostatin release.
abstract: To determine if, like insulin, somatostatin inhibits its own secretion from the pancreas, nonimmunoreactive analogs of somatostatin were perfused in an isolated dog pancreaticoduodenal preparation using a nonrecirculating system. [D-Trp8-D-Cys14]somatostatin, at a concentration of 200 ng/ml, blocked the response of somatostatin-like immunoreactivity (SLI) to cholecystokinin and arginine. When perfusion of the analog was discontinued, SLI release increased. At a concentration of 0.1 ng/ml, des Asn5-[D-Trp8]somatostatin lowered SLI levels significantly without significantly reducing glucagon levels. At a concentration of 1 ng/ml, des Asn5-[D-Trp8]somatostatin significantly inhibited SLI as well as insulin and glucagon release. Perfusion of glucagon at a concentration of 10 ng/ml failed to overcome the blockade of SLI and insulin release caused by 50 ng/ml des Asn5-[D-Trp8]somatostatin. The results are compatible with a direct inhibitory effect of somatostatin analogs upon SLI release and raise the possibility of a self-inhibiting action of the native hormone.
mesh_terms: D000818:Animals; D004285:Dogs; D005934:Glucagon / Q000378:metabolism / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D013004:Somatostatin / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D007328:Insulin; D013004:Somatostatin; D005934:Glucagon