Cd2+ effects on respiration and swelling of rat liver mitochondria were modified by monovalent cations

Inorganic phosphate stimulates the toxic effects of Tl+ in rat liver mitochondria

“…On the other hand, contraction of the succinate-energized mitochondria swollen in the medium with NH 4 NO 3 and P i , in experiments with Tl + ( Figure 3D, trace 1) is proven to be comparable with that found in experiments with Cd 2+ and DTT [29,30]. Stimulation of state 4 was found in the following experiments: with Tl + ( Figure 5) [3,6], or with K + and VAL [19,32], or with 5-10 μM Cd 2+ , or with 40-60 μM Cd 2+ alongside with RR or DTT [37,41,42]. DNP-stimulated respiration was not affected by Tl…”

“…It is to be noted that toxic effects of Tl + or of VAL on isolated mitochondria turned out to be comparable with effects of Cd 2+ in the presence of ruthenium red (RR), a potent inhibitor of the mitochondrial Ca 2+ -uniporter [34,35,41], or of dithiothreitol (DTT), an active SH reductant [30,42,43]. Swelling of energized mitochondria in the Tl acetate medium [3,6,7] was comparable with that found in the K acetate media with VAL [3] or with Cd 2+ [34,37,41]. The Cd 2+ -induced swelling was stronger increased by RR [34] or by DTT, administered after Cd 2+ Korotkov et al (in press).…”

“…Cd 2+ decreased state 3 and DNP-stimulated respiration [29,30,37,41,42] and fast discharged mito [43]. Considering the above data, we can conclude that effects of Tl + on DNP-stimulated respiration are mainly due to massive mitochondrial swelling (Figures 2, 3, and 5) [4], but not to inhibition of respiratory enzymes that takes place only in experiments with Cd 2+ [28,30,37,41]. Activity of another mitochondrial enzyme, MAO, was markedly inhibited by Cd 2+ [44] and only somewhat stimulated by Tl + [6,10] regardless of the presence of P i (Table 1).…”

“…Cd 2+ has stimulated state 4 and swelling in K acetate medium of mitochondria, followed by their uncoupling, and activated the K + /H + exchanger [34][35][36][37]. Toxic effects of Cd 2+ on mitochondria were increased in the presence of P i [28].…”

“…Cd 2+ , unlike Tl + , has an extremely high affinity to SH groups and thereby inhibits the enzymes [28,36,40]. Cd 2+ decreased state 3 and DNP-stimulated respiration [29,30,37,41,42] and fast discharged mito [43]. Considering the above data, we can conclude that effects of Tl + on DNP-stimulated respiration are mainly due to massive mitochondrial swelling (Figures 2, 3, and 5) [4], but not to inhibition of respiratory enzymes that takes place only in experiments with Cd 2+ [28,30,37,41].…”