Fig. 9.

Composition of islet (percentage of β-cells) and expression of MafA in foci resemble that in developing pancreas. (A) Insulin-expressing cells were often observed as scattered insulin⁺ cells in young foci and as islets in remnant or more mature foci. The proportion of insulin⁺ cells was measured as the number of insulin⁺ cells as percent of total synaptophysin⁺ cells in foci. Insulin⁺ cells comprised a lower percentage of endocrine cells in young regenerating foci than in islets of remnant. Cells counted are from five sham, five Px +3 days, five Px +4 days and three E18.5 embryonic pancreas. Data presented as mean ± s.e.m. (B,C)In young regenerating foci, MafA is expressed in only a portion of insulin⁺ cells (~20%) as in embryonic pancreas. This percentage of insulin⁺ MafA⁺ cells progressively increased to ~55% in mature foci, which is less than that (~85-90%) in remnant pancreases of same animals. Cells counted are from five Px +3-4 days, three E18 embryonic and two P7 postnatal rat pancreases. Data presented as mean ± s.e.m. **P<0.01, ***P<0.001.