Regulation of insulin and glucagon secretion from rat pancreatic islets in vitro by somatostatin analogues
2007 (English)In: Regulatory Peptides, ISSN 0167-0115, E-ISSN 1873-1686, Vol. 138, no 1, 1-9 p.Article in journal (Refereed) Published
Somatostatin is an inhibitor of hormone secretion through specific receptors (sst1-5). The aim of this study was to investigate the putative regulatory role of somatostatin analogues on the secretion of insulin and glucagon by rat pancreatic islets. After 48 h exposure only the non-selective agonists (somatostatin, octreotide and SOM-230) inhibited insulin accumulation. The inhibition of insulin secretion was accompanied by increased islet insulin contents. None of the analogues showed a consistent effect on the glucagon accumulation in the medium after 48 h. Since we observed a difference in the regulatory effect between the non-selective and selective analogues, combinations of selective analogues were studied. Combination of sst2 + sst5 agonists inhibited the medium insulin accumulation, while combination of sst1 + sst2 analogues caused a decrease in glucagon accumulation. After removal of somatostatin a rebound effect with increased insulin secretion were observed. This effect was reversed after 6 h. For SOM-230 insulin secretion continued to be suppressed even after the analogue was removed and returned to control values after 3 h. As for glucagon secretion there was an initial decline after culture with octreotide, while the other substances failed to induce any changes. In summary, non-selective somatostatin analogues or combinations of receptor selective analogues may cause inhibition of hormone secretion from rat pancreatic islets. For insulin and glucagon, combinations of sst2 + sst5 and sst1 + sst2, respectively may exert this effects. Thus, our data suggest that more than one sst must be involved to down-regulate islet glucagon and insulin secretion.
Place, publisher, year, edition, pages
2007. Vol. 138, no 1, 1-9 p.
Glucagon secretion, Insulin secretion, Pancreatic islets, Somatostatin analogues, Somatostatin receptors
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-93890DOI: 10.1016/j.regpep.2006.07.006ISI: 000243772600001PubMedID: 16935361OAI: oai:DiVA.org:uu-93890DiVA: diva2:167521