Effect of Neoplastic Cells on Plasma Clotting and Fibrinolytic System

Chromogenic substrates /S -2222, S -2233, S - 2251, KABI, Stockholm/ were employed to elaborate sensitive, quantitative methods for study of enzymatic and activator/inhibitor/activities of cells. Various neoplastic /JW sarcoma, thymoma, L-1210, L-5173Y-R and S etc/and normal cells were tested. The tests were performed using washed intact and fragmented cells and extracts. Application of purified, well defined proenzymes made it possible to measure factor X, prothrombin and plasminogen activators and platelet factor 3-hke activity using only 2x10⁶ cells in the system. Considerable differences were found. JW sarcoma cells contain plasminogen activator easily extractable with a non-ionic detergent /NP40/from cell surface and relatively large amounts of F.X activator which is only partly extracted. Lymphoid cells are practically deprived of plasminogen activator and contain much smaller amounts of F.X activator. All listed above activate prothrombin but only in the presence of small amounts of F.X. This coincides with their activity resembling PF 3. None or only traces of spontaneous activity was found using also several other chromogenic substrates.