Grotjan H E, Berkowitz A S, Keel B A
Mol Cell Endocrinol. 1985 Jul;41(2-3):205-9. doi: 10.1016/0303-7207(85)90024-3.
FSH beta in the medium and extracts of cultured rat anterior pituitary cells was quantitated with a heterologous radioimmunoassay utilizing anti-rFSH beta and hFSH beta as the standard and tracer. After 4 days in culture, extracts were prepared from washed cells, cells incubated for 6 h or 24 h in fresh medium or cells incubated for 6 h in the presence of 10(-7) M GnRH. FSH beta/rFSH molar ratios were approximately 0.05, 0.04, 0.21 and 0.35, respectively. The elevation in FSH beta/rFSH molar ratios in 24 h basal and GnRH-treated cultures was due in part to an increase in intracellular FSH beta. Both unstimulated and GnRH-treated cultures contained non-detectable quantities of FSH beta in the medium (less than 0.063 ng/100 000 cells; FSH beta/rFSH molar ratio less than 0.024). Thus, it appears that cultured rat anterior pituitary cells contain a small amount of uncombined FSH beta but that minimal quantities are released. Furthermore, GnRH may increase intracellular quantities of FSH beta but does not induce its release.
