Effects of dietary lead and zinc on fetal organ growth.

In order to further understand the effects of ingested lead (Pb) on the fetus and the possible interaction of the trace element zinc (Zn) with Pb, groups of rats with dated pregnancies were fed 0, 10, 50, 100, 200 or 500 mg/L of Pb in water throughout pregnancy. Diet was provided ad libitum. A group pair fed with the 200 mg/L of Pb group and a group fed both Zn and Pb, 200 mg/L, were also studied. Placental weight remained constant, but cell division and total protein level were decreased while cell size increased markedly. Fetal carcass and liver weight, cell division, and protein were decrease while cell growth was unchanged. Brain weight decreased while cell division, growth, and protein were unchanged. Kidney weight, cell division and protein level were unchanged but cell growth was decreased. Organ dry weight varied with wet weight while the percentage of water was unchanged. Whether pair feeding and Zn supplements improve carcass and liver weight is questionabel.