title: Urodilatin regulates renal dopamine metabolism.
abstract: BACKGROUND
  Sodium and water transport across renal proximal tubules is regulated by diverse hormones such as dopamine and urodilatin. We have previously reported that urodilatin stimulates extraneuronal dopamine uptake in external renal cortex by activation of the type A natriuretic peptide receptor, coupled to cyclic guanylate monophosphate signaling and protein kinase G. Moreover, urodilatin enhances dopamine-induced inhibition of Na+, K+-ATPase activity in renal tubules. The aim of the present study was to evaluate whether urodilatin could also alter renal dopamine synthesis, release, catabolism and turnover.
  
  
  METHODS
  The effects of urodilatin on dopamine synthesis, release, catabolism and turnover were measured in samples of renal cortex from Sprague Dawley rats.
  
  
  RESULTS
  The results indicate that urodilatin increases L-DOPA decarboxylase activity and decreases catechol-o-methyl transferase and monoamine oxidase activity. Moreover, urodilatin does not affect either dopamine basal secretion or potassium chloride-induced dopamine release in external renal cortex, and reduces amine turnover.
  
  
  CONCLUSIONS
  Both the present results and previous findings show that urodilatin modifies dopamine metabolism in external renal cortex of rats by enhancing dopamine uptake and synthesis and by decreasing catechol-o-methyl transferase and monoamine oxidase activity and dopamine turnover. Those effects taken together may favor dopamine accumulation in renal cells and increase its endogenous content and availability. This would permit D1 receptor recruitment and stimulation and, in turn, overinhibition of Na+, K+-ATPase activity, which results in decreased sodium reabsorption. Therefore, urodilatin and dopamine enhance natriuresis and diuresis through a common pathway.
authors: Department of Pathophysiology, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires - Argentina.
authors: Marcelo R
authors: MR
authors: Choi
authors: Marisa R
authors: MR
authors: Citarella
authors: Brenda M
authors: BM
authors: Lee
authors: Nicolás M
authors: NM
authors: Kouyoumdzian
authors: Natalia L
authors: NL
authors: Rukavina Mikusic
authors: Belisario E
authors: BE
authors: Fernández
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000502:physiology*; D002394:Catechol O-Methyltransferase / Q000378:metabolism*; D004231:Diuresis; D004296:Dopa Decarboxylase / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D007687:Kidney Tubules, Proximal / Q000378:metabolism; D008995:Monoamine Oxidase / Q000378:metabolism*; D009318:Natriuresis; D010446:Peptide Fragments / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D017447:Receptors, Dopamine D1; C056452:Ularitide; D009320:Atrial Natriuretic Factor; D008995:Monoamine Oxidase; D002394:Catechol O-Methyltransferase; D004296:Dopa Decarboxylase; D000254:Sodium-Potassium-Exchanging ATPase; D004298:Dopamine