Stable expression of human D3 dopamine receptors in GH4C1 pituitary cells.
Human D3 dopamine receptor DNA was stably transfected into GH4C1 pituitary cells. Displacement of iodosulpiride binding in hD3 transfected cells (Kd = 0.3 nM, Bmax = 89 fmol/mg protein) by dopaminergic ligands was indistinguishable from that of hD3 receptors in CHO cells. Only two clonal cell lines exhibited weak GppNHp-dependent shifts in [3H]N-0437 binding, and these were used for functional assays. Neither arachidonic acid metabolism, cAMP levels, inositol phosphate turnover, intracellular calcium, or potassium currents were consistently affected by dopamine (1-10 microM). The paucity of responses indicates that human D3 receptors do not couple efficiently to these second messengers in GH4C1 cells.
Seabrook
G R
GR
Merck Sharp & Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK.
Patel
S
S
Marwood
R
R
Emms
F
F
Knowles
M R
MR
Freedman
S B
SB
McAllister
G
G
D001095:Arachidonic Acids / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D008024:Ligands; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D011954:Receptors, Dopamine / Q000096:biosynthesis* / Q000235:genetics; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D014162:Transfection
D001095:Arachidonic Acids; C493593:DRD3 protein, human; D007295:Inositol Phosphates; D008024:Ligands; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D006160:Guanosine Triphosphate; D000242:Cyclic AMP; D011188:Potassium; D002118:Calcium; D004298:Dopamine