FIGURE 4.

Stimulation by glutamate of H₂O₂ generation by brain mitochondria oxidizing pyruvate and malate does not depend on whether BM were isolated in the absence (non-BSA-BM) or presence of BSA (BSA-BM). A, non-BSA-BM; B, BSA-BM (see “Experimental Procedures” for details). The incubation conditions were as in Fig. 1. Final volume was 1 ml. Additions were as follows: 5 μm Amplex red, 3 units of horseradish peroxidase, 50 units of superoxide dismutase (Sigma), 0.1 mg of rat brain mitochondria, 5 mm glutamate (G) + 2 mm malate (M), 2.5 mm pyruvate (P) + 2 mm malate. Malonate 5 mm was added before BM. Numbers associated with the traces show the rates of H₂O₂ production in pmol of H₂O₂/min/mg of BM protein. AU, arbitrary units.