Sodium transport regulation in the kidney collecting duct cells in mice with the Agouti yellow (Ay) mutation

Effects of mutation Agouti yellow (Aу) linked with melanocortin type of obesity in mice on mineralocorticoid regulation mechanism and non-genomic effect of aldosterone on sodium transport were studied. Measurements of blood plasma aldosterone concentration and of expressions of mineralocorticoid receptor and alpha 1 subunit of Na,K-ATPase in cortical collecting ducts (CCD) of mice C57BL/6j-Aу/a and C57BL/6j as congenic strain did not reveal any difference. Study of expression of epithelial sodium channel alfa-subunit (ENaC) that takes a part in sodium transport in principal cells of CCD have shown decreased mRNA contents of these protein in mice C57BL/6j-Aу/a. In C57BL/6j-Aу/a mice, there was no decrease in the permeability of the CCD cell plasma membrane for sodium ions under acute exposure to aldosterone (10 nM), in contrast to mice of the C57BL/6j congenic line. Based on the results of the entire study, one can suppose that the Aу mutation may affect the transport of sodium ions in CCD cells and possibly in other types of cells. These findings make actual studies of molecular mechanisms of the effects of Aу mutation on the regulation of renal function