Acute nephron reduction such as after living kidney donation may increase the risk of hypertension. Uninephrectomy induces major hemodynamic changes in the remaining kidney resulting in rapid increase of single nephron GFR and fluid delivery in the distal nephron. Decreased sodium (Na) fractional reabsorption after the distal tubule has been reported after uninephrectomy in animals preserving volume homeostasis. In the present study, we thought to specifically explore the effect of unilateral nephrectomy on ENaC subunits expression in mice. We show that -ENaC subunit surface expression was specifically downregulated after uninephrectomy, while the expression of the aldosterone-sensitive α-ENaC and α1-Na,K-ATPase subunits as well as of NKCC2 and NCC were not significantly altered. As acute nephron reduction induces a rapid increase of single nephron GFR resulting in a higher tubular fluid flow, we speculated that local mechanical factors such as fluid-shear stress (FSS) were involved in Na reabsorption regulation after uninephrectomy. We further explore such hypothesis in vitro in a model of FSS applied on highly differentiated collecting duct principal cells. We found that FSS specifically downregulates β-ENaC and -ENaC subunits at the transcriptional level through an unidentified heat-insensitive paracrine basolateral factor. The primary cilium as a potential mechanosensor was not required. In contrast, PKA and cPLA2 were involved, but we could not demonstrate a role for cyclooxygenase or epoxygenase metabolites.