[Primary culture of rat pituitary cells in serum-free medium]

A method for primary culturing of rat anterior and intermediate/posterior pituitary cells in complete serum-free defined medium (CSFM) is described. Dispersed pituitary cells were prepared by using a multiple enzyme digestion system. Insulin, transferrin and serum albumin were essential additives for maintenance of primary rat pituitary cells in CSFM. Morphological immunocytochemical and RIA studies during three weeks' culture indicated that beta-endorphin-like immunoreactivity (beta-End-IR) was contained in and released from pituitary cells. The secretion rate remained almost constant for 2 weeks after the 5th day in culture. This method provides an ideal in vitro model for studying the effects of various factors on the synthesis and release of beta-endorphin in pituitary cells and the mechanism of regulation of other target gland hormones.