D2- but not D3-dopamine receptors detected in the anterior pituitary

Using conditions which revealed high affinity binding sites for [3H]ADTN (KD of 1.6 nM), [3H]apomorphine (DK of 3.5 nM) and [3H]dopamine (KD of 1,5 nM) in the calf caudate nucleus, no such high affinity sites could be detected in the calf anterior pituitary gland. In contrast, high affinity binding sites for [3H]-spiperone were found in both the caudate and the anterior pituitary. The apparent absence of high affinity sites for these …