Distribution of zinc and copper in maternal and cord blood at delivery.

For 17 normal births, the concentrations of trace metals (zinc and copper) and related metalloenzymes, i.e., carbonic anhydrase isoenzymes (CA-I and CA-II) and Cu2Zn2 superoxide dismutase (SOD1) were simultaneously determined in maternal and cord blood at delivery. Eleven healthy nonpregnant women served as controls. CA-I concentration in maternal erythrocytes was higher than in controls (p less than 0.05), whereas the concentrations of both CA isoenzymes in cord erythrocytes were in the range of one seventh to one ninth of those in controls. On the other hand, the erythrocyte SOD1 concentration was constant. A very low total zinc concentration was noted in cord erythrocytes, and this was due to the low concentrations of both CA isoenzymes. Total copper concentration in maternal erythrocytes was significantly lower than in controls (p less than 0.05); in contrast, that in cord erythrocytes was significantly higher than in controls (p less than 0.05). Thus, variations in erythrocyte copper concentrations are due to changes in other forms of copper (not SOD1-derived). Copper concentration in maternal plasma was about three times higher than in controls, while copper concentration in cord plasma was less half of that in control plasma. Conversely, zinc concentration in cord plasma was significantly higher than in controls (p less than 0.05). The concentrations of these metals in maternal erythrocytes and plasma were significantly different from the respective concentrations in cord erythrocytes and plasma. Likewise, the concentrations of these metals in maternal and cord erythrocytes contrasted with the corresponding concentrations in their plasma.