Transerythrocytic concentrations of urea and creatinine in normals and in azotemic patients.

Preliminary studies in our laboratory suggested alterations in the distribution of urea and creatinine between red cells and plasma in azotemic patients, as compared to normal controls. The present studies compare plasma erythrocyte concentrations of urea and creatinine in azotemic patients and in control subjects. Effects of adding exogenous urea and creatinine to the blood of control subjects were also studied. The findings suggest alterations of solute distribution patterns in azotemic blood. Specifically, the proportions of the solutes in cells appear reduced in azotemia.