Cooperative effect of E2 and FGF2 on lactotroph proliferation triggered by signalling initiated at the plasma membrane

SOSA L.; GUTIéRREZ S.; PETITI J.P.; VACA A.; DE PAUL A.L.; TORRES A.I.

AMER PHYSIOLOGICAL SOC

Lugar: Bethesda; Año: 2013 vol. 305 p. 41 - 41

n the present work, we investigated the effect of 17beta-estradiol (E2) and basic fibroblast growth factor 2 (FGF2) on the lactotroph cell-proliferative response and the related membrane-initiated signaling pathway. Anterior pituitary mixed-cell cultures of random, cycling 3-mo-old female rats were treated with 10 nM E2, E2 membrane-impermeable conjugated BSA (E2-BSA), PPT (ERalpha agonist), and DPN (ERbeta agonist) alone or combined with FGF2 (10 ng/ml) for 30 min or 4 h. Although our results showed that the uptake of BrdU into the nucleus of lactotrophs was not modified by E2 or FGF2 alone, a significant increase in the lactotroph uptake of BrdU was observed after E2/FGF2 coincubation, with this effect being mimicked by PPT/FGF2. These proliferative effects were blocked by ICI 182,780 or PD-98059. The involvement of membrane ER in the proliferative response of prolactin cells induced by the steroid and FGF2 coincubation was confirmed using E2-BSA, and the association between ERalpha