Effect of Estradiol and FBS on PRL Cells,GH Cells,and PRL/GH Cells in Primary Cultures of Pituitary Cells from Prenatal Rats

Abstract

The effects of estradiol (E₂) treatment on prolactin (PRL) cells, GH cells, and PRL/GH cells in immature pituitary cells were determined using primary cultures from prenatal rats and immunocytochemistry with fluorescent antibodies. Anterior pituitaries obtained from fetuses on day 22 of pregnancy were monodispersed and cultured in chemically defined medium or medium containing 10% fetal bovine serum (FBS). After preincubation for 24 hr, E₂ (final concentrations were 0 M, 10^-8 M, 10^-7 M, and 10^-6 M) was added into each medium. After 72 hr of incubation, cells were subjected to Immunocytochemistry. E₂ stimulated the increase of PRL cells in a dose-dependent manner, and the PRL cell percentage cultured with FBS in all groups was significantly higher than that cultured in chemically-defined medium. PRL/GH cells also responded to E₂ in the same manner as PRL cells. E₂ was not effective in proliferating GH cells, and GH cell percentage significantly decreased with the addition of FBS into the medium. These results suggest that E₂ is dose-dependently capable of increasing immature PRL cells and/or PRL/GH cells in vitro. Moreover, there is a factor(s) in FBS that regulates the increase of these cells.