Localization of [3H]spiperone binding sites in the intermediate lobe of the rat pituitary gland.

[3H]Spiperone binding sites in all three lobes of the rat pituitary gland were studied using an in vitro autoradiographic technique. [3H]Spiperone binding was present throughout the pituitary gland but there was a much higher density of autoradiographic silver grains over the cells of the intermediate lobe than elsewhere. The density of spiperone binding sites in pars intermedia was comparable to that in sections of the rat corpus striatum. [3H]Spiperone binding was displaced by the specific dopamine agonist ADTN.