title: Ultrastructural study of pancreatic B cell regeneration in newborn rats after destruction by streptozotocin.
abstract: An ultrastructural study of endocrine cells was performed in the pancreas of rats treated with a single dose of streptozotocin on the day of birth. Most of the B cells present at birth were destroyed by streptozotocin but some survived and could again synthesize insulin after eliminating their altered fragments in phago-lysosome structures. New B cells were produced primarily by the formation of new islets from the small pancreatic ducts. A study of mitosis in colchicine treated animals showed that most B cells present on day 4 were formed by mitosis of undifferentiated cells. No significant division of preexisting differentiated B cells could be shown in streptozotocin treated rats. B cell regeneration in this newborn rat model is thus explained primarily by budding of new islets from the ducts.
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D007515:Islets of Langerhans / Q000648:ultrastructure*; D008938:Mitosis; D010183:Pancreatic Ducts / Q000473:pathology; D051381:Rats; D012038:Regeneration; D013311:Streptozocin / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D013311:Streptozocin