The method of histoautoradiography was used to study dynamics of indices of impulse and diluted marks in 2 cellular subpopulations of the kidney cortex: in the intertubular cells (IT-cells) and in the endothelium-like cells (E-cells) of the convoluted tubules. It is shown that under conditions of pathology (sublimate nephrosis) a part of IT-cells transforms into E-cells. A conclusion is made that IT-cells may be considered predecessor cells of the nephrothelium.