Locally formed dopamine modulates renal Na-Pi co-transport through DA1 and DA2 receptors.
The involvement of dopamine (DA) receptor subtypes in regulation of renal phosphate transport by DA, either exogenous or locally synthesized from L-dihydroxyphenylalanine (L-dopa) was evaluated in opossum kidney (OK) cells with proximal tubular phenotype. DA synthesis from L-dopa by OK cells was abolished by carbidopa and benserazide, two dissimilar inhibitors of aromatic L-amino acid decarboxylase. L-Dopa stimulated cyclic AMP generation and inhibited Na-dependent Pi uptake, and these effects were abolished by carbidopa and benserazide. The effects of L-dopa or DA on cyclic AMP generation and on Na-Pi co-transport were mimicked by SKF 38393, a DA1 receptor agonist, and were potentiated by S-sulpiride, a DA2 receptor antagonist. Bromocriptine, a DA2 receptor agonist, blunted in a pertussis toxin-dependent manner parathyroid hormone (PTH)-induced cyclic AMP generation and inhibition of Pi uptake. In contrast with PTH, neither L-dopa nor DA affected significantly the cytosolic calcium concentration. These results support the involvement of DA1 and DA2 receptors, positively and negatively coupled into adenylate cyclase respectively, in modulation of renal phosphate transport.
Department of Physiology, Faculté de Médecine X.-Bichat, Université de Paris, France.
R
R
Perrichot
A
A
Garcia-Ocaña
S
S
Couette
E
E
Comoy
C
C
Amiel
G
G
Friedlander
D037361:Adenylate Cyclase Toxin; D000818:Animals; D001545:Benserazide / Q000494:pharmacology; D001971:Bromocriptine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002230:Carbidopa / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D004298:Dopamine / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*; D007687:Kidney Tubules, Proximal; D007700:Kinetics; D007980:Levodopa / Q000494:pharmacology; D009893:Opossums; D010281:Parathyroid Hormone / Q000494:pharmacology; D037342:Pertussis Toxin; D010710:Phosphates / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D002352:Carrier Proteins; D010281:Parathyroid Hormone; D010710:Phosphates; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters; D010566:Virulence Factors, Bordetella; D001971:Bromocriptine; D007980:Levodopa; D001545:Benserazide; D012964:Sodium; D000242:Cyclic AMP; D037342:Pertussis Toxin; D002230:Carbidopa; D002118:Calcium; D004298:Dopamine