Human D3 dopamine receptor in the medulloblastoma TE671 cell line:: cross-talk between D1 and D3 receptors

In search of a cell line in which the D-3 dopamine receptor is expressed endogenously, we found that the neuron-derived human medulloblastoma cell line TE671 expresses the human D-3 (hD(3)) and D-1 (hD(1)) receptor, but neither the D-2 or D-4 receptors. Exposure of TE671 cells to the D-3 agonist 7-OH-DPAT (DPAT), or to the D-1 agonist SKF-38393 (SKF) increased the expression of hD(3) or hD1 mRNA, respectively. Moreover, whereas DPAT had no effect on hD(1) mRNA levels, stimulating the cells with SKF caused an increase in both hD(1) and hD(3) transcript levels. These results suggest (1) that following ligand stimulation, hD(3) and hD(1) receptors are upregulated to enhance their own receptor expression, and (ii) that upregulation of hD(1) receptor transcripts leads to a stimulation of the hD(3) dopamine receptor transcripts. (C) 1998 Federation of European Biochemical Societies.