Involvement of Distinct Signaling Pathways in Activin- Induced Increases in FSH Secretion and Enlargement Of FSH Cell Population in the Rat Pituitary

摘要

Activin-A induces increases in FSH secretion, as well as the number of immunoreactive FSH cells, in cultured rat pituitary cells. In this study, we examined whether mechanisms involved in these two actions of ac- tivin-A are identical or not, with respect to the involvement of cellular proliferation and of Ca~2+-dependent signaling pathways. Treatment with activin-A (25 ng/ml) for 48 h caused increases in the number of cultured rat anterior- pituitary cells that incorporated BrdU, a thymidine analog.