ABSTRACT
GH3 cells are derived from rat pituitary tumor cells that secrete prolactin and growth hormone, and important in studying prolactin-secreting pitutary tumors. This study was performed to examine the effects of polylysine on growth and differentiation of GH3 cells by means of (a) cell attachment assay (b) cell count and bromodeoxyuridine labeling and (c) immunohistochemistry for prolactin in the absence or presence of epidermal growth factor (EGF). Cell shape, attachment to the culture surface and growth of GH3 cells were not affected by polylysine coating. The percentages of prolactin-immunoreactive cells were higher in the cells cultured on the polylysine-coated surface compared to those on the plastic surface. Cell number and BrdU incorporation were lower in the EGF-treated cells on both culture surfaces. The results provided basic information on the effects of polylysine coating on GH3 cells in culture and suggested that polylysine coating was useful for the study on GH3 cells because it enhanced cell differentiation as well as it provided stronger attachment than plastic surfaces.