Effect of aprotinin, EACA and heparin on growth and vasopeptide system of Murphy-Sturm lymphosarcoma.

The effect of aprotinin, EACA and heparin on the growth of the transplanted rodent Murphy-Sturm lymphosarcoma and on several components of the tumor kinin-forming enzyme system was studied. Therapy was administered for 15 days, 3 times daily, one day after tumor transplant. Tumor weights and biochemical parameters (prekallikrein, kininogen and kininase) were measured on the 8th, 10th, 12th and 15th day of therapy. Both aprotinin and heparin significantly inhibited (p less than 0.01) tumor growth by the 15th day, compared to control, saline-administered animals. EACA did not affect the tumor growth rate at any time period. Tumor prekallikrein and kininogen levels were significantly higher (p less than 0.01) in the aprotinin-treated animals. Kininogen levels were higher in the EACA-treated tumors during the latter phase of growth. None of the agents affected the increase in tumor kininase activity that occured during the growth of the tumors. The tumor inhibition and biochemical data suggest the involvement of proteases in the neoplastic process.