[Interrelation of the endocrine and exocrine portions of the pancreas]

Ultrastructural organization of cells and functional activity of the rat pancreas was studied under peroral administration of 80% glucose solution (4 times, 20 ml every 15 min) and a single subcutaneous administration of insulin (5 units). When glucose was administered, both the exocrine and endocrine parts of the pancreas responded with an increased insulin production, revealed by means of the immunoreactive method, with an intensified synthesis of the digestive enzymes (amilase, protease). Ultrastructural organization of beta-cells demonstrated their sharp functional strain resulting in exhaustion, and in the acinar cells--in an increased secret formation. On the contrary, insulin administration resulted in a sharp decrease of the functional activity in the exocrine part of the pancreas, that was reflected correspondingly in the ultrastructural organization of the acinar cells, while the structure of beta-cells demonstrated a delayed excretion of insulin-containing granules from their cytoplasm.