Figure 9.

The dependence of the rate of the pyruvate/[¹⁴C]-phosphoenolpyruvate (PEP) exchanges in either rat (A) or rabbit (B) kidney mitochondria on the external pyruvate concentration. From [12]. With permission from Aracne Editrice, 2021. [¹⁴C]-PEP-loaded mitochondria (1 mg protein) were incubated at 4 °C in 1 mL of a standard medium consisting of 15 mM KCl, 1 mM MgCl₂, 100 mM TRIS-HCl, pH 7.4 plus 1 µg of µg rotenone, 3 µg oligomycin in the presence of 5 mM arsenite and 10 mM oxalate. After 1 min incubation, the assay was started with pyruvate, at the concentrations indicated, and was stopped after 6 seconds by the addition of 10 mM phenylsuccinate. The exported ¹⁴C-PEP was assayed as reported above. Both RKM and RBKM were loaded with ¹⁴C-PEP and its efflux measured according to the stop inhibitor method.