Figure 2.

Both 17-β-estradiol and progesterone regulate amphiregulin through their cognate receptors in the pubertal mammary gland. Pubertal 4-week-old BALB/c mice were OVX, allowed to recover for 3 weeks, and then treated for 5 days with vehicle control (C), E2, P, or E2+P, as described in the Materials and Methods section. (A) RT-PCR analysis of amphiregulin (AREG) in response to hormone treatments. Fold change is relative to control treatment. (B) Immunofluorescent detection of AREG (green) in ducts after E2, E2+ICI, P, P+RU486, and after P treatment in both ducts and end buds. Nuclei were counterstained with DAPI (blue). Scale bar, 25 μm.