Abstract
Background: The current study was designed to perform a transmission electron microscopic investigation focusing on the dark and light pancreatic acinar beta-cells of young domesticated pig (Sus Suidae).Materials and methods: This study depended on the fresh pancreatic specimens from 5 healthy young (2-month-old) pigs that were collected immediately after they were slaughtered at the abattoir of Abdelkader Alexandria, Egypt.Results and Conclusions: In our findings, the acinar pancreas was formed of pyramidal pancreatic acinar cells with large spherical nuclei of condensed hetero-chromatin at the periphery and prominent eccentric nucleoli. Zymogen granules were observed at the apical region of the acinar cells, and they appear as electron dense bodies. Numerous mitochondria and Golgi complexes observed in the acinar cell cytoplasm. The electron dense acinar cells were joined by junctional complex-es. The rough endoplasmic reticulum was more prominent in the electron-dense acinar cells than did electron-lucent acinar cells. There was no connective tissue capsule separate the acinar portion of pancreas from the pancreatic islets. The pancreatic islets mainly formed of beta-cells. The irregular alpha-cells possess numerous small granules. The cytoplasmic beta-cells granules were surrounded by hallow area and enclosed by a limiting membrane. Delta cells were generally polygonal in shape and found in clumps throughout the islet and they were also identified in between beta-cells. Their granules were of moderate electron density and were gen-erally smaller than beta-cells' granules. The limiting membrane was tightly enclosed the delta cells granules and the hallow area around the granule were found similar to the granules of beta-cells.