Salt-induced downregulation of renal aquaporins is prevented by losartan

► High salt diet downregulated AQP-1 and AQP-2 in proximal tubule and collecting duct. ► High salt diet upregulated Ang II, TGF-β1 and α-SMA and downregulated eNOS. ► Losartan increased diuresis and natriuresis, favoring urinary sodium concentration. ► Losartan prevented the profibrogenic response and normalized AQP-2 in HS-L. ► AQP-1 expression was upregulated by losartan in both NS-L and HS-L.