Time-dependent effect of heat-induced PCD on the ascorbate pool Levels of ASC and DHA were measured in control cells (C) and in cells collected immediately (I0) and 6 (I6) and 24 (I24) h after heat shock. Values represent mean ± se of five experiments. The redox state was calculated as the ratio ASC/(ASC + DHA), using mean values of the concentrations of the individual substances.