Beta cell count instead of beta cell mass to assess and localize growth in beta cell population following pancreatic duct ligation in mice

Pancreatic-tail duct ligation (PDL) in adult rodents has been reported to induce beta cell generation and increase beta cell mass but increases in beta cell number have not been demonstrated. This study examines whether PDL increases beta cell number and whether this is caused by neogenesis of small clusters and/or their growth to larger aggregates. Total beta cell number and its distribution over small (100 µm) clusters was determined in pancreatic tails of 10-week-old mice, 2 weeks after PDL or sham. PDL increased total beta cell mass but not total beta cell number. It induced neogenesis of small beta cell clusters (2.2-fold higher number) which contained a higher percent proliferating beta cells (1.9% Ki67+cells) than sham tails (