FIGURE 5.

Structural and functional properties of glomerular mitochondria in salt-sensitive (SS) hypertension. (A) A schematic illustration of the imaging configuration, as well as representative images of the podocytes in the isolated glomeruli stained with mitoPY1 to visualize H₂O₂ in mitochondria (green), and Hoechst (blue) to label nuclei. Images were obtained with a 63× oil objective, NA 1.4. Dotted lines show podocyte body outlines (obtained from TL images). Graph on the right summarizes the fluorescence transients obtained from mitoPY1-stained podocytes of freshly isolated glomeruli in response to acute addition of 10 μM H₂O₂. Background auto fluorescence of mitoPY1 is shown (transient obtained in the absence of H₂O₂). N, five rats per group, at least four glomeruli per animal, with five to nine ROIs (podocytes) analyzed per glomerulus. Statistical analysis performed using one-way repeated measures ANOVA with Holm–Bonferroni for post hoc means comparison. (B) Representative electron microscopy images of the mitochondria ultrastructure in the podocyte of the glomeruli isolated from NS and HS diet fed rats. Scale bar is shown on the graph; asterisk denotes autophagosome formation; arrowheads show cristae. FP, foot processes; GMB, glomerular basement membrane; PB, podocyte body. (C) Mitochondria of glomeruli of HS diet fed animals exhibit higher levels of super oxide, as shown by fluorescence of MitoSox, six rats in each group, three replicates were measured per each experimental animal. Data were compared using a one-way ANOVA with Holm–Sidak post hoc test. (D) Relative expression of Gpx4 in the fraction of freshly isolated glomeruli. (E) The antioxidant capacity of renal cortical tissue compared in NS vs. HS diet fed animals (expressed in mM Trolox). Data were compared using a one-way ANOVA with Holm–Sidak post hoc test, each point represents a separate animal.