Abstract:3,4‐Dihydroxyphenylethylamine (dopamine) and β‐adrenergic receptor agonists and antagonists were assessed for their effects on cyclic AMP accumulation in human astrocytoma derived clone D384 cells. Dopamine, SKP 38393, and 2‐amino‐6,7‐dihydroxy‐l,2,3,4‐tetrahydronaphthalene increased cyclic AMP content withKavalues of 2.0, 0.2, and 1.6 μM. The D1‐selective antagonists SCH 23390 (Ki, 1.2 nM) and SKF 83566 (Ki, 0.8 nM) were over 5,000‐fold more potent than the D2‐selective antagonist domperidone (Ki, 6.7 μM) at inhibiting dopamine stimulation of cyclic AMP formation. SCH 23388 (Ki, 560 nM;theS‐enantiomer of SCH 23390) was 400‐fold less potent than SCH 23390. Isopren‐aline, adrenaline, salbutamol, and noradrenaline increased cyclic AMP content withKavalues of 0.13, 0.12, 0.22, and 7.60 μM. The β2‐selective antagonist ICI 118,551 (Ki, 0.8 nM) was almost 8,000‐fold more potent than the β,‐selective antagonist practolol (Ki, 5.9 μM) at inhibiting isoprenaline stimulated cyclic AMP accumulation. These results demonstrate that D384 cells express D1‐dopamine and β2‐adren‐ergic receptors linked to adenylate cyclase. Furthermore, the dopamine receptor expressed by D384 cells exhibits a pharmacological profile typical of a mammalian striatal D1‐re‐ceptor and therefore the use of this clone represents