Figure 2.
Ductal side branching and epithelial cell proliferation in mammary glands after combined estrogen plus progestin treatment. Ovariectomized C57BL/6 females were treated for 3 wk with different doses of MPA (A and C) or drospirenone (B and D) plus 100 ng estradiol. The formation of ductal side branches within the mammary gland (A and B) as well as the proliferation of mammary epithelial cells (C and D) was analyzed. ED50 values for both progestins in the respective readout paradigms are depicted.