Antidiabetic activity of a highly potent and selective nonpeptide somatostatin receptor subtype-2 agonist

Endocrinology. 2006 Oct;147(10):4664-73. doi: 10.1210/en.2006-0274. Epub 2006 Jul 20.

Abstract

Somatostatin inhibits both glucagon and insulin secretion. Glucagon significantly contributes to hyperglycemia in type 2 diabetes. Despite its function in the inhibition of glucagon secretion, somatostatin fails to reduce hyperglycemia in type 2 diabetes, due to a parallel suppression of insulin secretion. Five pharmacologically distinct somatostatin receptor subtypes (sst(1)-sst(5)) mediate the effects of somatostatin on a cellular level. Pancreatic A cells express sst(2), whereas B cells express sst(5). In this study, we describe a novel approach to the treatment of type 2 diabetes using a highly sst(2)-selective, nonpeptide agonist (compound 1). Compound 1 effectively inhibited glucagon secretion from pancreatic islets isolated from wild-type mice, whereas glucagon secretion from sst(2)-deficient islets was not suppressed. Compound 1 did not influence nonfasted insulin concentration. In sst(2)-deficient mice, compound 1 did not have any effects on glucagon or glucose levels, confirming its sst(2) selectivity. In animal models of type 2 diabetes in the nonfasted state, circulating glucagon and glucose levels were decreased after treatment with compound 1. In the fasting state, compound 1 lowered blood glucose by approximately 25%. In summary, small-molecule sst(2)-selective agonists that suppress glucagon secretion offer a novel approach toward the development of orally bioavailable drugs for treatment of type 2 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Glucose / metabolism
  • Diabetes Mellitus, Type 2 / genetics
  • Diabetes Mellitus, Type 2 / metabolism
  • Dogs
  • Glucagon / metabolism
  • Growth Hormone / metabolism
  • Hypoglycemic Agents / pharmacology*
  • In Vitro Techniques
  • Insulin / metabolism
  • Insulin / pharmacology
  • Islets of Langerhans / drug effects
  • Islets of Langerhans / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Obese
  • Rats
  • Receptors, Somatostatin / agonists*
  • Receptors, Somatostatin / genetics

Substances

  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin
  • Receptors, Somatostatin
  • somatostatin receptor sst2A
  • Growth Hormone
  • Glucagon