RESUMEN
The rabbit pancreatic structure at histological and ultrastructural level, in different intervals after ligature of pancreatic duct, was studied. Changes in the exo- and endocrine parenchyma were observed. Canalicular structures and conjunctive tissue replace the destroyed acinar cells. In some of the islets the B cells are degranulated or necrotic. Some islets contain infiltrations of lymphocytes, macrophages and granulocytes. Cavities formed by necrotic endocrine cells could appear. The A and B cells proliferation is observed in the new-formed clusters of endocrine cells and ductless. The mechanism of this process is similar to that of the islet formation during the embryonic development or in nesidioblastosis, but they are never transformed in the definitive islet of Langerhans.