Regulation and Expression of D-1, but not D-5, Dopamine Receptors in Human SK-N-MC Neuroblastoma Cells

Abstract

Human SK-N-MC neuroblastoma cells endogenously express functional D-1-like dopamine receptors. The recent identification of at least two distinct type of D-1-like receptors, D-1 and D-5, lead us to investigate the precise molecular identity of the receptors expressed in these cells. By using specific primer sets and amplification of the mRNA by RT-PCR, we show that only D-1, but not D-5, dopamine receptors are expressed in these cells. Treatment of cells with 100 μM dopamine initially caused an upregulation in D-1 mRNA expression, followed by attenuation of the message compared to control, untreated cells. The D-1 receptors in SK-N-MC cells, whose expression is controlled by dopamine in a bimodal manner, may be important in understanding how these receptors are regulated at the molecular level.