Distribution and ultrastructure of somatostatin-immunoreactive cells in the pancreas of Rana esculenta.

Apart from a description of the general organization of the endocrine pancreas, the present study is focussed on the distribution and ultrastructural morphology of somatostatin-immunoreactive cells in the pancreas of the frog Rana esculenta. For light-microscopic histochemistry, the peroxidase-antiperoxidase technique was used. For the ultrastructural investigation, we employed the immunogold method. The endocrine pancreas of R. esculenta is composed of numerous islet-like structures, which contain several small somatostatin-immunoreactive cells arranged in the form of clusters. Often, however, single somatostatin cells are randomly distributed among the acinar tissue of the pancreas. These individually arranged elements possess long processes which terminate on exocrine pancreatic cells. The ultrastructural features of somatostatin-immunoreactive cells speak in favor of their endocrine and paracrine functions.