Lead toxicity in the pregnant rat. II. Effects of low-level lead on delta-aminolevulinic acid dehydratase activity in maternal and fetal blood or tissue.

Abstract

Lead was administered to pregnant rats in drinking water (5 ppm) from day 1 to day 18 or 21 of gestation, at which time the dams and fetuses were sacrificed. The red blood cell count and hemoglobin concentration were significantly lower in the lead-treated fetuses than in untreated controls on day 21 of gestation, but not in the lead-treated dams. The delta-aminolevulinic acid dehydratase (ALAD) activity of erythrocytes was significantly reduced in the lead-treated dams and their fetuses on days 18 and 21 of gestation. AL AD activity in the liver was significantly higher in the leadtreated fetuses than in the controls. There was no significant difference in placental AL AD activity between the lead-treated and control animals. Lead in tissues increased significantly in the liver of the lead-treated fetuses.There were significant positive correlations between the maternal and fetal blood lead level, liver lead level and erythrocyte ALAD activity. There was a significant negative correlation between the maternal and fetal liver ALAD activity.