Fig. 6. Upregulation of ouabain-resistant Na⁺-ATPase in proximal tubule cells and downregulation in cardiomyocytes: treatment with Losartan (alone or in combination) predominates over treatment with Valproate, with opposite profiles depending on the tissue. Panels A and B show Na⁺-ATPase activity in basolateral membranes from renal cortex corticis tubules and plasma membranes from left ventricle cardiomyocytes, respectively. Empty bars: normonourished rats (C); black bars: malnourished rats (M). Vertical dashed lines separate normonourished and malnourished groups in the rest of the panels. The left sections correspond to normonourished rats; the right sections correspond to malnourished rats. Abbreviations of the groups are indicated on the abscissae, according to the nutritional status and the timeline of pharmacological interventions with Losartan, Valproate or a combination of both drugs, as described in the text and in Supplementary Table 1. The data are mean ± SEM (n = 4-5). Na⁺-ATPase and (Na⁺+K⁺)ATPase were assayed in the same membrane preparation. Differences were assessed by Student's t-test. The p values are indicated within the panels.