Fig. 2.

EE treatment does not affect histomorphological parameters on the lactating mammary gland. A) Representative histological sections stained with hematoxylin and eosin collected from females exposed to vehicle, 0.01 or 1 μg EE/kg/day from pregnancy day 9 through lactational day 20. Arrows indicate lobuloalveolar structures, arrowheads indicate adipose tissue. Scale bar represents 50 μm. B) A higher magnification image demonstrating lobules of varying size. Scale bar represents 20 μm. C) Quantification of data collected from histological sections evaluating the volume fraction of the mammary gland comprised of lobuloalveolar units. D) Quantification of lobule size. Neither the volume fraction of lobuloalveolar units nor the lobule size was affected by EE treatment.