Chronic lead treatment affects dopaminergic control of prolactin secretion in rat pituitary.

The effect of lead exposure on dopaminergic mechanisms regulating prolactin (PRL) secretion was studied in rats by measuring dopamine (DA) and dihydroxyphenylacetic acid hypothalamic concentrations and DA receptor density in the hypothalamus and pituitary of lead-exposed animals. [3H]Sulpiride was used as dopamine receptor ligand. A decrease of dihydroxyphenylacetic acid (DOPAC) hypothalamic concentrations and a decrease of DA receptor density in the pituitary are shown. The decreased [3H]sulpiride binding in the pituitary is consistent with the elevated serum PRL concentrations previously described in lead-exposed rats.