Figure 4.

T₃-induced changes in cortical marker expression in the inner cortex. A and B, Immunofluorescence analysis showing that T₃ treatment expanded the 20αHSD-positive cell zone (red) and in the innermost cortical zone induced coexpression of the outer cortical, zona fasciculata marker AKR1B7 (green, or yellow for double positive). Mice were treated with T₃ or saline from P14 to P28. C and D, Representative higher magnification of panels A and B showing cells positive for both 20αHSD and AKR1B7. E and F, Immunofluorescence analysis showing prominent expression of steroidogenic enzyme 3βHSD (red) in the expanded inner zone next to the medulla (green, tyrosine hydroxylase) after T₃ treatment. G and H, Immunofluorescence analysis showing normal expression of CYP11B2 in the zona glomerulosa under saline or T₃ treatment. In all panels, DAPI (blue) marks cell nuclei. Abbreviations are the same as in Figure 3. Scale bars for panels A, B, G, and H, 100 μm; for C–F, 50 μm.