17β-Estradiol stimulates the translocation of endogenous estrogen receptor cc at the plasma membrane of normal anterior pituitary cells

In the present work we aimed at identifying ER alpha in the plasma membrane of normal anterior pituitary cells and investigated if 17 beta-estradiol was able to induce their subcellular redistribution. Our results show that about 8% of anterior pituitary cells expressed ERa in the plasma membrane, with the geometrical mean fluorescence intensity being increased after steroid hormone treatment. 17 beta-Estradiol and the selective ERa agonist PPT induced an increase of ERa expression in the plasma membrane and activated the PKC alpha/ERK 1/2 pathway in a time-course not compatible with genomic actions, thus supporting the notion of membrane-initiated effects. These findings suggest that 17 beta-estradiol stimulates the translocadon of endogenous ER alpha to the plasma membrane, consequently modulating this ER pool and leading to cellular biological effects in normal anterior pituitary gland. (C) 2012 Elsevier Ireland Ltd. All rights reserved.