title: Dopaminergic receptors and angiotensinogen gene expression in opossum kidney cells.
abstract: To investigate whether expression of the renal angiotensinogen gene is regulated by dopaminergic receptors, we used opossum kidney (OK 27) cells with a fusion gene containing the 5'- flanking regulatory sequence of the rat angiotensinogen gene fused with a human growth hormone (hGH) gene as a reporter [pOGH, angiotensinogen nucleotide (N) -1498/+18], permanently integrated into their genomes. The level of expression of pOGH (angiotensinogen N-1498/+18) in OK 27 was evaluated by the amount of immunoreactive hGH (ir-hGH) secreted into the culture medium. In the absence of 3-isobutyl-1-methylxanthine (IBMX), addition of dopamine (10(-13) to 10(-5)M) had minimal effect on the expression of the pOGH (angiotensinogen N-1498/+18) in OK 27 cells. In the presence of IBMX, addition of low concentrations (10(-13) and 10(-7) M) of dopamine stimulated the expression of pOGH angiotensinogen N-1498/+18) in OK 27 cells in a dose-dependent manner, whereas high concentrations (i.e., > 10(-7) M) had minimal effect. The stimulatory effect of dopamine on the expression of pOGH (angiotensinogen N-1498/+18) was inhibited by the presence of SCH-23390 (D1-dopaminergic receptor antagonist) and spiperone (D2-dopaminergic receptor antagonist), but not by ketanserin (5 HT2/5HT1c-serotonergic receptor antagonist). Moreover, the stimulatory effect of dopamine was inhibited by the presence of U-73122 (an inhibitor of phospholipase C and phospholipase A2) or staurosporine (an inhibitor of protein kinase C) or (R)-p-adenosine 3',5'-cyclic monophosphorothioate (Rp-cAMP[S]; an inhibitor of cAMP-dependent protein kinase AI and II). Addition of low concentrations (10(-13) to 10(-9)M) of SKF-82958 (D1-dopaminergic receptor agonist) or PPHT (D2-dopaminergic receptor agonist) also stimulated the expression of pOGH (angiotensinogen N-1498/+18). The stimulatory effect of SKF-82958 was inhibited by the presence of SCH-23390 or Rp-cAMP[S], whereas the effect of PPHT was inhibited by the presence of spiperone or staurosporine. These studies demonstrate that the expression of pOGH (angiotensinogen N-1498/+18) in OK 27 cells is modulated by dopaminergic receptor agonists.
authors.affiliation: University of Montreal, Maisonneuve-Rosemont Hospital, Research Center, Quebec, Canada.
authors.forename: T T
authors.initials: TT
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Lachance
authors.forename: A
authors.initials: A
authors.lastname: Delalandre
authors.forename: S
authors.initials: S
authors.lastname: Carrière
authors.forename: J S
authors.initials: JS
authors.lastname: Chan
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000808:Angiotensinogen / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D004298:Dopamine / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism* / Q000502:physiology*; D009893:Opossums; D010446:Peptide Fragments / Q000378:metabolism; D051381:Rats; D011954:Receptors, Dopamine / Q000502:physiology*
chemical_list: D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D010446:Peptide Fragments; D011954:Receptors, Dopamine; D000808:Angiotensinogen; D015056:1-Methyl-3-isobutylxanthine; D004298:Dopamine