Immunohistochemical analysis of the pancreas of STZ-treated ERTF-Pdx1-EGFP mice without Dox.

<p>ERTF-Pdx1-EGFP mice were given STZ 4 weeks after Dox withdrawal. Six weeks after STZ injection, their pancreata were used for immunostaining analyses. (A) Immunostaining for insulin (red) and EGFP (green). Bar = 200 μm. (B-G) Magnified views of the islet regions including the dotted line-box in (A). Bars = 25 μm. Merged images including DAPI staining are also shown in (D) and (G). (H) Insulin-positive cells were rarely seen in the STZ-treated wild-type controls. (I) The percentage of EGFP-positive cells among insulin-positive islet cells was determined for each islet of the pancreas from three STZ-treated and three STZ-untreated ERTF-Pdx1-EGFP mice, 10 weeks after Dox withdrawal (<i>n</i> = 18–40 for each mouse). Each bar represents the mean for a single animal (19%, 28%, 24%, 63%, 60%, and 69%, respectively). The proportion of EGFP-positive cells among insulin-positive islet cells was significantly higher in the STZ-treated animals than in the STZ-untreated controls (<i>P</i> < 0.05).