Different Effects of Prostaglandin E₁, E₂ and D₂ on Pancreatic Somatostatin Release

Summary

The effects of PGE₁ PGE₂ and PGD₂ on somatostatin, insulin and glucagon secretions were investigated at various glucose concentrations using the isolated perfused rat pancreas. At glucose concentrations varying from 0 to 16.7 mM, PGE₁, and PGE₂ enhanced somatostatin release in a glucose dose-dependent manner. PGE₁ did not significantly stimulate insulin secretion at glucose concentrations of 4.4 mM or less, but did at glucose concentrations of 8.8 mM or more. PGE₂ augmented insulin release at 4.4 and 16.7 mM glucose, but not in the absence of glucose. Glucagon release was induced by PGE₁ and PGE₂ in a biphasic pattern with the maximal response in the absence of glucose. Like PGE₁ and PGE₂, PGD₂ stimulated insulin and glucagon release in a glucose-related fashion. PGD₂, however, was not capable of stimulating somatostatin release at various glucose concentrations even in the presence of 16.7 mM glucose. In conclusion, PGE₁ PGE₂, and PGD₂ increase insulin and glucagon secretion in a glucose-dependent manner. PGE₂ and PGE₂ also stimulate somatostatin release, but PGD₂ has no effect on somatostatin secretion at the doses studied.

Key-Words:

Prostaglandin E ₁, E ₂, D ₂ - Somatostatin - Insulin - Glucagon - Glucose - Isolated Perfused Rat Pancreas