Mechanism(s) of Toxic Action of Zn²⁺ and Selenite: A Study on AS-30D Hepatoma Cells and Isolated Mitochondria

Figure 5

Simultaneous recordings of four mitochondrial parameters (respiration, ΔΨ_mito, K⁺, and Ca²⁺ fluxes) with the help of O₂, TPP⁺, K⁺, and Ca²⁺-selective electrodes after treatment of isolated RLM with Zn²⁺ in the absence (a) or presence of CsA (b). Mitochondria (1 mg protein/mL) were incubated at room temperature in a medium containing 120 mM NaCl, 2 mM NaH₂PO₄, 10 mM HEPES (pH 7.4), 5 mM Glu, and 5 mM Mal. The additions of Zn²⁺ (5 μM), K⁺ (100 μM), Ca²⁺ (200 μM), and dithionite are indicated by arrows. [CsA] was 1 μM. 20 μM of Ca²⁺ were present in the assay medium from the beginning of experiment. Downward deflection indicates decrease in [O₂], [TPP⁺], [K⁺_free], and [Ca²⁺_free] in the medium. The results are representative for a series of two independent experiments.

(a)

(b)