Expression of ER-α in mammary tissues.

<p>Female ACI rats were treated with E2, Tam or Tam + E2 for 240 days as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025125#s4" target="_blank">Materials and Methods</a> section. At the end of the experiment, mammary tissues were collected and used for immunohistochemistry as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025125#s4" target="_blank">Materials and Methods</a> section. Formalin-fixed/paraffin-embedded mammary sections were immunostained with ER-α antibody. Nuclear expression of ER-α is shown in representative sections (arrow). (a) The mammary tissue of a representative control ACI rat; (b) E2-treated mammary tissue; (c) Tam-treated mammary tissue; and (d) Tam + E2-treated mammary tissue. 100× magnification.