ABSTRACT
OBJECTIVE: The aim of this study was to characterize cells expressing insulin and amylase in adult human pancreas. METHODS: We applied serial section and immunohistochemistry to pancreas samples from 5 adult nondiabetic subjects (2 men and 3 women;mean age, 65.8 years; random plasma glucose level, 5.1 mM). Cells expressing insulin and amylase were captured by immunofluorescence and confocal miscroscopy. RESULTS: We found a widespread occurrence of insulin-producing cells in exocrine acini and amylase-reactive acinar cells in well-formed islets. The insulin-producing cells in exocrine acini predominantly formed single and double cell units though cell clusters, and islands occurred. Acini containing insulin-producing cells outnumbered the islets with a factor of approximately 5. Confocal microscopy and double immunostaining identified acinar A-cells coexpressing both amylase and insulin. CONCLUSIONS: The acinar A-cells represent a distinct category of pancreatic cell populations and might be possible endogenous progenitors of insulin-producing cells in normal and abnormal metabolic homeostasis.
