ROS formation in rat brain slices after 4 and 10 h of perfusion with immunosuppressants. The values are given as mean±s.d. (n=6). Significance levels: *P<0.05; **P<0.01; ***P<0.001. Rat brain slices were perfused with cyclosporine (500 μg l−1), everolimus (100 μg l−1), sirolimus (100 μg l−1), and/or tocopherol (500 μmol l−1). The fluorescent agent DCF was added for the last 30 min. Slices perfused with 1 mM H2O2 for 30 min served as positive controls. CsA, cyclosporine; RAD, everolimus; SRL, sirolimus, VitE, tocopherol.