Monolayer culture of neonatal pig pancreatic islet cells

Pancreatic islet cells from pigs (3-12 days old) were maintained in monolayer culture at 37 degrees C for greater than 30 days. Cultures were maintained in enriched Medium 199 with 5% fetal calf serum and with the glucose concentration being cycled between 11.10 and 27.75 mmol/l every 2 days. The presence of B cells in the cultures was demonstrated by insulin secretion into the culture medium, cell staining with aldehyde fuchsin and immunofluorescence. A cells in the cultures were monitored by glucagon secretion into the medium. The absence of exocrine cells was determined by the inability to detect alpha-amylase in the culture medium. Insulin secretion determined over a 34-day period, was found to diminish after 12 days in culture. The fall in levels of extractable B cell insulin with time correlated with the levels of insulin secreted into the medium. Response to short term glucose stimulation (2 h in serum-free medium) was determined on days 6, 10 and 12 in culture. Morphological changes appeared after 25 days in culture, although on day 33 insulin secretion was 62.5 microU X culture-1 X day-1. DNA synthesis (determined by 3H-thymidine incorporation and autoradiography) was demonstrated (day 12, 39.4 +/- 0.9 labelled cells/culture). These findings suggest that pig islet cell monolayer cultures are a useful tool for morphological and biochemical studies and that neonatal pig islets are a potential source of material for transplantation.