Effect of salicylate on copper metabolism in maternal and fetal rats.

Pregnant Wistar rats were treated with 5 oral doses of 100 or 300 mg/kg salicylic acid from day 16 to 20 of gestation. At day 21 of gestation, copper concentrations were measured in serum, liver and cell organelles of liver from dams and litters after cell fractionation. Salicylate caused a reduction of maternal serum Cu and an increase in fetal liver Cu. The increase of Cu in fetal liver was proportional to the Cu content of the organelles. It was concluded that salicylate bound Cu and transferred Cu from maternal serum to the fetus. The increase in fetal liver Cu was explained by displacement of Zn from Zn-metallothionein by Cu, because Zn-metallothionein is high in fetal liver and Cu has a higher affinity to metallothionein than Zn. Such a mechanism was not significant in maternal liver because of the low Zn-metallothionein content in maternal liver.