Human fetal pancreas has been obtained, after the therapeutic termination of pregnancy with prostaglandin F2α. Pancreatic explants were studied in a perifusion system and maintained in organ culture for up to 3 wk. Insulin biosynthesis was stimulated by glucose; however, the incorporation of 3H-L-leucine into proinsulin was surprisingly high (52% after 3 h) vs. insulin (48%), which suggests a possible block in the conversion of proinsulin to insulin. Insulin secretion was stimulated during perifusion with 19.3 mM glucose (1.6× prestimulation level), 1.5 μM glucagon (2.4), 5 mM leucine (2.4), 10 mM arginine (2.7), and 10 mM theophylline (10.0).
Insulin biosynthesis and secretion were maintained in organ culture. After 12 days there was a 3.4-fold increase in insulin secretion in the presence of 22 mM glucose compared with 5.5 mM glucose, and the explant insulin content rose in the presence of high glucose levels by 89%. The acute insulin secretory response to 10 mM theophylline was maintained after culture.
These studies suggest that human fetal pancreas should be considered as a potential source of donor tissue for pancreas transplantation in human diabetes.