Administering 15N-labelled
glycine, 15 N incorporation into
serum albumin and its excretion into urine and feces, together with
nitrogen balance were investigated in 3 nephrotic and 2 normal adults. Furthermore, 15N-labelled
urea was injected into a nephrotic adult and a glomerulonephritic adult, both advanced in
azotemia and treated on
low protein diet, and a normal subject on a normal diet, to examine the amounts of 15N incorporation into
serum albumin. In the 3 nephrotic patients whose
nitrogen balance was almost maintained, incorporation of 15N-glycine into
serum albumin has been proved greater than in the normal subjects. In any of the above patients, 15N excretion into urine was less than in the normal subjects. Fecal 15N excretion was 2.0--2.5 % of the doses, indicating that approximately 98 % of 15N-glycine was absorbed. In the nephrotic patients, 15N incorporation into
serum albumin examined by 15N-labelled
urea administration was more accelerated than in the glomerulonephritic patients and was negligible in the control subject on a normal diet.