Mechanism of ghrelin-evoked glucagon secretion from the pancreas of diabetic rats

Ernest Adeghate, Hasan Parvez

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

Objective: Ghrelin is a newly discovered peptide, which was first demonstrated in the epithelium of rat stomach. The purpose of the study was to examine the effect of ghrelin on glucagon secretion from pancreatic tissue fragments of normal and diabetic rats. Methods: Diabetes was induced by streptozotocin (60 mg Kg body weight-1) given intraperitoneally. Four weeks after the onset of diabetes, pancreatic fragments of normal and diabetic rats were incubated with different concentrations (10-12-10-6 M) of ghrelin. Glucagon release was measured using radioimmunoassay technique. Results: Ghrelin failed to stimulate or inhibit glucagon secretion from normal rat pancreas. However, it induced significant increases in glucagon secretion from pancreatic tissue fragments of diabetic rats. Either atropine (muscarinic cholinergic receptor antagonist) or propranolol (β-adrenergic receptor antagonist) or yohimbine (α2-adrenergic receptor antagonist) or diltiazem (calcium channel antagonist) did not affect ghrelin-glucagon interaction. Moreover, a combination of atropine, propranolol and yohimbine had no significant effect on the interaction of ghrelin with glucagon. Conclusion: The ghrelin-induced glucagon secretion in diabetic rats is not controlled via cholinergic or adrenergic pathways. In conclusion, it appears that the main target of ghrelin in the rat endocrine pancreas is not glucagon-producing cells but rather insulin secreting cells which are more involve in weight gain and body growth.

Original languageEnglish
Pages (from-to)432-436
Number of pages5
JournalNeuroendocrinology Letters
Volume23
Issue number5-6
Publication statusPublished - Oct 2002

Keywords

  • Atropine
  • Diabetes mellitus
  • Diltiazem
  • Ghrelin
  • Glucagon secretion
  • Pancreas
  • Propranolol
  • Radioimmunoassay
  • Rat
  • Yohimbine

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Neurology
  • Endocrine and Autonomic Systems
  • Clinical Neurology
  • Psychiatry and Mental health

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