Functional consequences of prenatal exposure to lead in immature rats

Long-Evans dams were given 0.5% lead acetate as their sole drinking solution two weeks before and throughout pregnancy. Their offspring were transferred to normal surrogate dams on the second day after birth. From days 5 through 30, the rat pups were observed for the appearance of developmental landmarks and given behavioral tests (surface righting, negative geotaxis, eye opening, left-right position discrimination and reversal, ambulation and head dipping). Pups of pair-fed-and-watered as well as normal control dams were also transferred to surrogates and received the same tests. Although the lead-exposed rat pups had markedly elevated blood and brain lead on the day of birth (which were still significantly elevated on day 16), they showed no delay, impairment, or any other change on the various functional measures.