Fibroblast growth factor modulates the release of transferrin from cultured Sertoli cells

The acute and chronic effects of basic fibroblast growth factor (bFGF) on transferrin (TF) secretion from Sertoli cells were investigated by using reverse hemolytic plaque assays which enabled the visualization of release from individual cells in culture. We found that acute treatment with bFGF stimulates the release of TF from some but not al Sertoli cells in cultures obtained from 20-day-old rats. Chronic treatment with this growth factor resulted in increases in overall cell number in cultures from animals of each age tested (8-20 days of age). In contrast, this long-term treatment decreased markedly the proportions of Sertoli cells that secreted TF but only in cultures from 10-day-old animals. When taken together, these findings of acute and chronic influences of bFGF on TF secreting cells support the possibility that bFGF not only contributes to the modulation of the day-to-day release of certain substances from Sertoli cells, but may also influence development of the portions of the cell population that secrete these substances.