Substrate Modulation of Fatty Acid Effects on Energization and Respiration of Kidney Proximal Tubules during Hypoxia/Reoxygenation (original) (raw)
Figure 1
Effects of oleate on energization and respiration of permeabilized tubules: comparison of complex I and complex II-dependent substrates.
Direct effects of oleate on energization of permeabilized rabbit tubules measured with safranin O uptake (panels A–C) and respiration (D) supported by either succinate or the combination of complex I dependent substrates, α-ketoglutarate, malate, and glutamate (AMG). Sets of typical safranin O uptake tracings (inverted fluorescence) are shown in panels A and B and group averages for those studies are in panel C. Numbers adjacent to each tracing in panels A are the concentrations of oleate added in µM. In panel C, “Peak” indicates the maximal uptake compared to the uptake seen without added oleate using succinate as substrate measured in the presence of delipidated albumin to eliminate the effect of endogenous fatty acids. “End” indicates the final level reached at the end of the 600 second measurement period, which can be less than the peak if there has been decay of ΔΨm. The panel D respiratory rates (RR) are given as percentages relative to “Control” rates without added oleate using succinate as substrate. Shown are both the initial rate produced by oleate and then the rate at the end of 600 seconds of measurement. Values in panels C and D are means±SEM for N = 3–5 except 4 µM oleate with AMG where the N was 2. *P<0.05, #P<0.01, +P<0.001 vs. corresponding succinate group.