Figure 6.

T₃ sensitivity of the TRβ1-positive inner cortex in nulliparous or parous adult female mice. A, X-gal staining showing expansion of the TRβ1-positive inner cortex in response to T₃ in both nulliparous and parous adult female mice (6 mo old, given T₃ or saline for 2 wk before analysis). B, Immunofluorescence analysis showing substantial loss of 20αHSD expression after pregnancy (parous) and the inability of T₃ to recover 20αHSD in parous mice. DAPI (blue) marks cell nuclei. Scale bars, 100 μm. ic, inner cortex; m, medulla; zF, zona fasciculata.