Effects of lead on movement of albumin into brain

The offspring of CD-1 mice were exposed either to 0.5% sodium acetate or lead acetate in the drinking water from the time of birth. After weaning, locomotor activity was evaluated. The lead-exposed mice were hyperactive and smaller than the sodium-exposed mice. Methylphenidate, caffeine, ephedrine and pemoline all caused an increase in the movement of radioiodinated serum albumin (RISA) into the brain of sodium-exposed mice. In the lead-exposed animals the movement of RISA into the brain was decreased in the mice given saline (control), amphetamine, methylphenidate or ephedrine relative to the corresponding sodium-exposed animals. These changes are opposite to those previously found using radioactive pertechnetate as the probe of the function of the blood-brain barrier (BBB). This provides further evidence for the selectivity of the BBB in handling different types of molecules.