Somatostatin inhibits insulin release via SSTR2 in hamster clonal beta-cells and pancreatic islets.
Somatostatin (SST) inhibits pancreatic endocrine secretion. It is generally accepted that SSTR2 and SSTR5 mediate the inhibition of glucagon and insulin release, respectively. The present study was performed to test the hypothesis that SSTR2, but not SSTR5, mediates SST-induced inhibition of insulin release in hamster beta-cells. Both hamster clonal beta-cells HIT-T15 and pancreatic islets were used to test this hypothesis. Both SST and a nonpeptide SSTR2 agonist L-779,976 (1-100 nM) inhibited insulin release from HIT-T15 and islets in a concentration-dependent manner. In contrast, nonpeptide agonists for SSTR1, 3, 4 and 5 at the highest concentration studied (1 microM) failed to inhibit insulin release. PRL-2903, a peptide SSTR2 antagonist (0.1-1 muicroM), antagonized SST-induced inhibition of insulin release in a concentration-dependent manner. Taken together, we conclude that, in hamster beta-cells, SST inhibits insulin release via SSTR2 but not SSTR5.
Yao
Cheng-Yu
CY
Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
Gill
Manmeet
M
Martens
Catherine A
CA
Coy
David H
DH
Hsu
Walter H
WH
D000577:Amides / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D007211:Indoles / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism*; D010456:Peptides, Cyclic / Q000494:pharmacology; D017481:Receptors, Somatostatin / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013004:Somatostatin / Q000494:pharmacology*
D000577:Amides; D007211:Indoles; D007328:Insulin; C121854:L 779976; C121568:PRL 2903; D010456:Peptides, Cyclic; D017481:Receptors, Somatostatin; D013004:Somatostatin; C094573:somatostatin receptor 5; C093733:somatostatin receptor 2