Fig. 9.

Activation of the FAS receptror causes the reactivation of intercellular ROS-mediated apoptosis signalling 12,500 MKN-45 cells per assay received no inhibitors (control) or 2 mM histidine (HIS), 2.4 mM l-NAME or 50 mM taurine (TAU) either 15 min before or 1 h after addition of the indicated concentrations of antibodies directed against the FAS receptor. The percentages of apoptotic cells were determined after 12 h. Statistical analysis: Apoptosis induction by anti-FAS receptor as well as its inhibition by histidine and l-NAME added prior to the antibody were highly significant (p<0.001), whereas later addition of these inhibitors did not cause significant inhibition. In contrast, there was no significant difference between the effects of early and late addition of taurine (p<0.001) that inhibited apoptosis induction by anti-FAS receptor up to 10 µg/µl with high significance (p<0.001).