Urea metabolism in an azotaemic woman with normal renal function

The blood-urea of a 43-year-old woman with normal renal function was 150 mg. per 100 ml. because she regularly consumed about 400 g. of protein daily. She had no symptoms of uraemia and her haemoglobin concentration was normal. Although she had a very large body-urea pool she degraded no more urea than healthy individuals on a normal diet. The failure of endogenous urea hydrolysis to increase in proportion to the blood-urea in renal failure has tentatively been ascribed to toxic effects of compounds retained with urea in renal failure; the findings in this azotaemic patient, who had neither signs nor symptoms of uraemia, cast doubt upon that explanation.