FIGURE 4.

Menadione can induce release of calcium from mitochondria of AR42J cells (pericam measurements). AR42J cells were transfected with fluorescent mitochondrial ratiometric calcium pericam. Fluorescence was measured over time before and after menadione in cells pretreated for 10 min with 10 μm thapsigargin (A) or for 10 min with 200 nm and subsequently with 10 μm thapsigargin (B). The ratio of pericam fluorescence is shown in Aa and B, while original traces of pericam fluorescence (488 nm and 430 nm excitation) are shown in Ab. The change in fluorescence after menadione treatment under each condition (A and B) was compared (C) (mean ± S.E., n = 8–11 per group, *, p < 0.05).