Copper Metabolism in Normal Subjects

Abstract

The various aspects of copper metabolism studied in normal subjects and in normal pregnant women are presented. The values (mean and 95 per cent limits) obtained in normal nonpregnant subjects are as follows: total serum copper, 114 µg. per 100 ml. (81 to 147 µg. per 100 ml.); direct-reacting serum copper, 7 µg. per 100 ml. (0 to 20 µg. per 100 ml.); ceruloplasmin, 33 mg. per 100 ml. (25 to 43 mg. per 100 ml.); total erythrocyte copper, 89 µg. per 100 ml. packed cells (66 to 112 µg. per 100 ml.); erythrocuprein, 16 mg. per 100 ml. packed cells (10 to 22 mg. per 100 ml.); urine copper, 15 µg. per twenty-four hours (5 to 25 µg. per twenty-four hours); spinal fluid copper, 6 µg. per 100 ml. (2 to 11 µg. per 100 ml.); total liver copper, 8 mg. (4 to 13 mg); total brain copper, 8 mg. (7 to 10 mg.); total kidney copper, 1.2 mg. (0.2 to 2.8 mg.); total heart copper, 0.9 mg. (0.5 to 1.2 mg.); and total spleen copper, 0.1 mg. (0.02 to 0.2 mg.). The total amount of copper in the body of a man weighing 70 kg. is estimated to be about 80 mg. The values (mean and 95 per cent limits) obtained in women during the third trimester of pregnancy are as follows : total serum copper, 239 µg. per 100 ml. (150 to 317 µg. per 100 ml.); direct-reacting serum copper, 29 µg. per 100 ml. (10 to 55 µg. per 100 ml.); ceruloplasmin, 84 mg. per 100 ml. (54 to 114 mg. per 100 ml.); erythrocyte copper, 75 µg. per 100 ml. (48 to 102 µg. per 100 ml.); and erythrocuprein, 19 mg. per 100 ml. packed cells (10 to 28 mg. per 100 ml.). A number of metabolic pathways for copper are outlined. The pivotal and important position of the small direct-reacting fraction of serum copper is emphasized. The daily turnover of copper is estimated. Of the 2.0 to 5.0 mg. of copper ingested daily, 0.6 to 1.6 mg. is absorbed. From 0.5 to 1.2 mg. is excreted in the bile, 0.1 to 0.3 mg. passes directly into the bowel, and 0.01 to 0.06 mg. appears in the urine.