Fig. 1.

Representative respirograms of 200-day-old C57BL/6J (a) and mtNOD mice (b). Shown is the sequential addition of substrate according to the first experimental approach ‘protocol I’ (see Table 1 in Supplementary Materials) and the resulting changes in O₂ concentration (black line) and O₂ flux (grey line), which were further evaluated. The addition of mitochondria to the medium results in an immediate increase in oxygen consumption (first peak in A and B marked with asterisk) leading to equal oxygen concentration between mitochondria suspension and medium. G3P—glycerol-3-phosphate