The pancreatic islets of the teleost Scorpaena scropha. An ultrastructural study with particular regard to fibrillar granules

摘要: The principal pancreatic islets of the teleost Scorpaena scropha are found ultrastructurally to contain four different kinds parenchymal cells, viz.α1-(= D), α2-, β-and “agranular” cells. β-cells show considerable variations in shape secretory granules. A peculiar feature is that many these granules composed fibrillar subunits, often parallel arrangement. All β-granules surrounded by membranes and between membrane granule core there a moderately wide electron lucent space. density cytoplasm varies somewhat. α2-cells possess typical with an dense closely applied membrane. α1-cells also but less core. Also α-cells opacity varies. cells mainly characterized low cytoplasmic density, narrow cisterns endoplasmic reticulum sometimes laminated Golgi complex. Small “immature” occasionally seen significance remains obscure.