The significance of L-amino acid decarboxylase and DARPP-32 in the kidney

Am J Hypertens. 1990 Jun;3(6 Pt 2):11S-13S. doi: 10.1093/ajh/3.6.11s.


This study examines the role of endogenous dopamine (DA) for the regulation of renal tubular sodium (Na) transport. The enzyme L-amino acid decarboxylase (L-AADC) that converts L-dopa to DA has been localized to the proximal tubule cells with immunocytochemistry. Locally formed DA will inhibit the activity of Na-K-ATPase, the enzyme that yields energy to active Na transport. The effect is of physiological importance during high salt diet. The phosphoprotein DARPP-32, a DA1 receptor associated third messenger is abundant in the medullary thick ascending limb of Henle (mTAL). DARPP-32 is phosphorylated after activation of DA1 receptors. DARPP-32 is in its phosphorylated form a potent phosphatase inhibitor. Activation of the DA1 receptor in mTAL with the DA1 agonist SKF 82526 causes dose-dependent inhibition of Na-K-ATPase activity. The effect involves activation of cAMP protein kinase. It is likely that this effect is potentiated by DARPP-32.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Aromatic-L-Amino-Acid Decarboxylases / metabolism*
  • Dopamine / physiology
  • Dopamine and cAMP-Regulated Phosphoprotein 32
  • Kidney / metabolism*
  • Kidney Tubules, Proximal / physiology
  • Levodopa / pharmacology
  • Loop of Henle / metabolism
  • Nerve Tissue Proteins / metabolism*
  • Nerve Tissue Proteins / physiology
  • Phosphoproteins / metabolism
  • Receptors, Dopamine / physiology
  • Sodium / metabolism
  • Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors


  • Dopamine and cAMP-Regulated Phosphoprotein 32
  • Nerve Tissue Proteins
  • Phosphoproteins
  • Receptors, Dopamine
  • Levodopa
  • Sodium
  • Aromatic-L-Amino-Acid Decarboxylases
  • Sodium-Potassium-Exchanging ATPase
  • Dopamine