FIGURE 3

Antioxidants prevent the inhibitory effect of TR on endothelial cells. N-acetylcysteine: NAC (3 mM), glutathione: Glut. (3 mM) and Tiron (5 mM) were co-incubated with 0.1 M of TR for 24 h and DNA synthesis was measured as described in Materials and Methods. The effect of antioxidants was calculated as per cent of DNA synthesis compared with that in control cells treated with antioxidants alone. Inhibition of DNA synthesis in BCE by TR was fully restored by co-incubation with antioxidants. DNA synthesis in control cells was about 50 000 c.p.m.