Afferent and efferent interference of cell-mediated cytotoxic reactions by heparin.

Heparin influenced the induction (afferent interference) and effector (efferent interference) phases of cell-mediated cytotoxic reactions against FBL-3 cells, a syngeneic Friend virus-induced leukemia in inbred C57BL/6 mice. Heparin was cytotoxic at high concentrations (greater than or equal to 100 U/ml) and inhibitory for cell-mediated cytotoxic response at lower concentrations (less than or equal to 50 U/ml).