Radiolabel incorporation associated with tissue factor production in cultured human fibroblasts and smooth muscle cells

Abstract

Incorporation of 14C leucine and 3H glucosamine into cellular components increases concomitant with production of tissue factor (thromboplastin) activity in human fibroblasts and smooth muscle cells after subculture. After an initial burst, coagulant activity and incorporation of leucine and glucosamine both decline (within 12 hours). In smooth muscle cells, a minor activity peak was associated with the early burst of synthetic activity. 48 hours after subculture of these cells, tissue factor had increased substantially with lesser but measurable increments of glucosamine and leucine incorporation. The radiolabel content and tissue factor activity of the material released from the cells by trypsin digestion, presumably representing the surface coat, rose and fell in a manner similar to the total cell culture. We conclude that changes of tissue factor levels in the cultured cell may be one aspect of more generalized synthetic events.