Substrate Modulation of Fatty Acid Effects on Energization and Respiration of Kidney Proximal Tubules during Hypoxia/Reoxygenation (original) (raw)
Figure 9
Effects of glutamate and rotenone on succinate-supported respiration of normoxic and H/R rabbit tubules.
A. Measurements of energization using safranin O uptake done in parallel with the respiration studies on the same preparations. Abbreviations for the experimental groups testing different conditions during safranin O uptake are as for Fig. 8. Tubules were subjected to 67.5±SEM for N = 4. Figure symbols indicate #P<0.01 or +P<0.001 vs. corresponding normoxic values. Values for glutamate and rotenone-treated H/R groups without dBSA were significantly different from the corresponding group with succinate alone, P<0.05. Delipidated albumin (dBSA) significantly improved energization under all the H/R conditions (P<0.001). B. Measurements of respiration. Oxygen consumption was assessed sequentially under basal conditions, then after addition of ADP to stimulate oxidative phosphorylation, then during suppression of the ADP-induced oxidative phosphorylation by oligomycin (OLIGO), then during maximally-stimulated uncoupled respiration produced by carbonyl cyanide-m-chlorophenylhydrazone (CCCP). Studies were done with and without addition of dBSA on tubules previously subjected to either normoxic incubation or H/R. Values are means±SEM for N = 4. There were no significant effects of glutamate and/or rotenone under any condition except for a small decrease of the ADP rate in the normoxic glutamate+rotenone+dBSA group (P<0.05). Basal and oligomycin rates did not significantly differ between normoxic and H/R tubules. dBSA significantly lowered the basal and oligomycin rates in all groups (P<0.001 normoxic, P<0.01 hypoxic). ADP and CCCP rates of H/R tubules were significantly lower than the corresponding normoxic at *P<0.05 or #P<0.01 under all conditions. dBSA did not significantly affect the ADP rates, but it significantly increased the CCCP rates in the normoxic S and SR groups and the H/R S, SG, and SR groups, Ps<0.05 or better.