EFFECT OF PROGESTERONE ON PROTEINS VECTORIALLY SECRETED BY GLANDULAR EPITHELIAL-CELLS OF GUINEA-PIG ENDOMETRIUM - MODULATION BY HOMOLOGOUS STROMA

Endometrial glandular epithelial cells were subcultured on matrix-coat ed filters in bicameral chambers in a serum-free chemically defined me dium. The cells were untreated or treated with 50 nmol progesterone l( -1) or 10 nmol oestradiol l(-1) or 10 nmol oestradiol l(-1) plus 50 nm ol progesterone l(-1) and the proteins secreted into the basal or apic al compartment were analysed after [S-35]methionine labelling. Compare d with the untreated cells, oestradiol treatment did not affect the el ectrophoretic profiles of proteins secreted by the glandular epithelia l cells in either compartment. Progesterone treatment induced a decrea se in the labelling of 88 and 53 kDa proteins secreted in the apical a nd basal compartments and an increase in the labelling of a 28 kDa pro tein. Moreover, progesterone specifically induced the apical secretion of a 137 kDa protein. Interaction between the epithelial and stromal cells was also investigated. When stromal cells were cultured in the b asal compartment under the epithelial monolayer, the progesterone effe ct on the apical secretion of the 137 kDa protein and basal secretion of the 88 and 28 kDa proteins were altered, whereas this progesterone effect was not altered when the epithelial cells were cultured alone i n media conditioned with stromal cells. Interactions between epithelia l and stromal cells modified the effect of progesterone on protein sec retion by the epithelial cells.