Dopamine receptors in the anterior lobe of the human pituitary gland: autoradiographic localization.

We examined the distribution of dopamine and serotonin receptors in human pituitary gland by light microscopic autoradiography using [3H]spiperone as a binding ligand. Clusters of specific binding sites for [3H]spiperone were observed in the anterior pituitary. This clustering is similar to the clustering of lactotrophs observed in immunohistochemical studies. No specific binding sites for [3H]spiperone were present in the posterior lobe of the pituitary gland. We found no evidence for the presence of serotonin-2 receptors (i.e. cinanserin-displaceable [3H]spiperone binding) in human pituitary.