Virtually all researchers on pancreatic and islet cell biology are familiar with the occasional sight of a single islet cell or small islets seemingly sprouting from the ducts of a section of adult pancreas. The incidence of such observations is amplified under a number of experimental or pathological conditions. For a long time, the obvious conclusion has been that islets might indeed be formed in or near the ducts, migrating at a later point to the acinar surroundings. BrdU labeling studies led to Bonner-Weir and colleagues to hypothesize that pancreatic regeneration in the partially pancreatectomized rat occurs through two pathways, namely: the self-replication of existing endocrine and exocrine cells; and the proliferation and differentiation of the ductal epithelium into new Read the rest of this entry »