AROMATASE-ACTIVITY IN HUMAN ADIPOSE-TISSUE STROMAL CELLS - THE EFFECT OF FETAL BOVINE SERUM FRACTIONS ON DEXAMETHASONE-STIMULATED AROMATIZATION

Aromatization in human adipose stromal cells is stimulated by dexamethasone, but only in the presence of fetal bovine serum (FBS). To determine whether there was a specific fraction of FBS responsible for this stimulation, FBS was fractionated either by a pressure-driven ultrafiltration membrane or by Sephadex gel filtration techniques. The stimulating factor(s) appeared to be in the FBS fraction of 150,000-300,000 M(w) by Sephadex filtration. Conversely, FBS fractions with < 30,000 M(w) as separated by the former method inhibited the dexamethasone-stimulated aromatization of cultured adipose stromal cells. Bovine serum albumin, which constituted the major portion of FBS, had no discernible effect on the dexamethasone action on the aromatization of these cells.