All known beta cell secretagogues, such as glucose, arginine, gastrointestinal hormones, and tolbutamide, support the release of SST from delta cells [7].
As a result, alpha and delta cells forming a mantle in nondiabetic rats are now spread within mostly the decreased beta cell mass [19-21].
Less attention has been paid to the role of other cell types, namely, delta cells. Previously, besides insulin secretion also the SST secretion as a response to glucose was found impaired in the perfused pancreas of GK rats [23]; hence we specifically focused on delta cells and SST PI content in fully developed diabetes.