Ontogeny of catecholamine and GABA levels in rat brain: lack of effect of perinatal lead exposure.

In this study we report the ontogeny of noradrenaline, adrenaline, dopamine, and gamma-aminobutyric acid (GABA) in the rat striatum and the effect of perinatal exposure to low levels of lead. Lead administered in the maternal drinking water (100, 300 and 1000 ppm) from conception to weaning had no effect on the ontogeny of catecholamines. There was a 50% decrease in the levels of GABA at 10 days in rats exposed to the highest dose of lead, but no other changes were observed in lead-exposed rats at 21 and 30 days of age. These results contrast with our previously reported decrease in the levels of striatal proenkephalin products in lead-exposed rats, and suggest that this inhibitory effect of lead does not represent a generalised neurochemical toxicity.