Concentrations of copper, zinc and selenium in brain and kidney of second trimester fetuses and infants.

The concentrations of copper (Cu), zinc (Zn) and selenium (Se) in the brain and kidneys of second trimester fetuses (abortion cases) and infants (deceased before three months of age) were determined. Concentrations of Cu in brain, 0.31-1.6 mg/kg wet weight, increased with age, and were, on the average, three times higher in the brains of infants than of fetuses. In kidneys, Cu concentrations ranged between 0.34 and 2.9 mg/kg, and increased with age after birth. Concentrations of Zn in the brain decreased significantly with age in the fetuses, from about 7 mg/kg at post-conceptional week 12 to less than 5 mg/kg at week 20, but increased again postnatally. In kidneys, Zn concentrations (12-37 mg/kg) increased in parallel with the increase in tissue density. Concentrations of Se in brain, 0.072-0.14 mg/kg, decreased with age in the fetuses, but increased with age postnatally. Kidney Se concentrations (0.16-0.55 mg/kg) did not change significantly with age during the fetal period, but increased about 2.5 times during the postnatal period. There was a significant association between the concentrations (on molar basis) of Zn and Cu in kidneys, but not in brain. There was no correlation between the concentrations of Cu, Zn or Se and those of mercury, cadmium and lead, previously determined in the same samples, with the exception of mercury and Se in kidneys.