Estrogen control of uterine tissue factor messenger ribonucleic acid levels

One of the early responses of the immature rat uterus to stimulation by estradiol (E2) is an increase in the specific activity and synthesis of a discrete set of proteins including tissue factor (TF). Increases in TF are associated with stimulation of cell growth in mouse and human fibroblasts and endothelial cells. The increase in TF activity following E2 stimulation of the uterus is due to an increase in TF messenger RNA (mRNA). A 2- to 4-fold increase in mRNA is observed 1 h after injection, reaches a maximum at 3 h, and is reduced at 6 h. The increase is hormone specific and occurs at low levels of E2 (0.66 micrograms/kg). The E2 effect is abolished by actinomycin but not by cycloheximide. The changes in TF mRNA occur in a similar time scale and at similar E2 doses as the increases in the uterine proto-oncogenes c-jun and c-fos.