Figure 5.

Release of Cyt c. (a) Western blot of Cyt c reveals appearance of Cyt c in the cytoplasm of cerebrocortical cells 3 and 6 h after NMDA receptor activation. (b) Cyt c was detected not only in membrane (m) but also in cytosolic (c) fractions 6 h after exposure to NMDA, NMDA plus BA, or staurosporine; however, under control conditions (Left) cytoplasmic Cyt c remained virtually undetectable. Under all conditions, most of the Cyt c remained in the membrane fraction. (c) Inhibition of caspases with 50 μM z-VAD-fmk (z = benzyloxycarbonyl; fmk = fluoromethyl ketone) during NMDA receptor activation did not prevent release of Cyt c. (d) Inhibition of caspase-8 with 20 μM z-IETD-fmk blocked staurosporine-induced release of Cyt c. (e) Model of staurosporine and NMDA activation of caspases and Cyt c release.