Mouse trophoblast cells are constitutive producers of thromboplastin (factor III) in vitro

Trophoblasts from murine placenta synthesize thromboplastin in the absence of inducing agents and a functional complement system, nor is the rate or level of synthesis enhanced by inducers. A serum factor which is destroyed/removed by addition of oxalate and subsequent dialysis appears to enhance the ability of trophoblasts to synthesize thromboplastin.