[Ultrastructural characteristics of a monolayer culture of pancreatic islet cells from pig fetuses].

B-, A- and D-insulocytes have been identified by electron microscopy as early as the first 24 h of cultivation. After 3-5 days of the culture growth the B-cells displayed development of the endoplasm net, hypertrophy of the Golgi apparatus and an increased number of vacuoles and granule-like formations. When the time of cultivation was prolonged (7-12 days), in the B-cell cytoplasm there appeared signs of increasing dystrophic changes indicative of cell ageing.