Figure 4.

SS^Nox4−/− rats exhibit lower renal H₂O₂ levels on a HS diet. A) An example of the preparation for the measurement of H₂O₂ levels in vivo by the biosensors amperometry. The kidney was exposed and mounted in a kidney cup. The biosensor was inserted into the kidney cortical or medullar layer and connected to a dual-channel potentiostat for amperometry recordings. The reference electrode was placed onto the kidney surface and attached to the potentiostat to ensure reduced electrical noise. Interstitial perfusion of catalase was simultaneously performed. B) Representative recording of interstitial H₂O₂ levels. Perfusion of catalase (2 μg/ml) is shown. C) Summary graphs of the renal cortex and medulla interstitial H₂O₂ in SS and SS^Nox4−/− rats fed a HS diet. *p < 0.05.