Dominant role of prostaglandin E2 EP4 receptor in furosemide-induced salt-losing tubulopathy: a model for hyperprostaglandin E syndrome/antenatal Bartter syndrome

J Am Soc Nephrol. 2005 Aug;16(8):2354-62. doi: 10.1681/ASN.2004070556. Epub 2005 Jun 23.

Abstract

Increased formation of prostaglandin E2 (PGE2) is a key part of hyperprostaglandin E syndrome/antenatal Bartter syndrome (HPS/aBS), a renal disease characterized by NaCl wasting, water loss, and hyperreninism. Inhibition of PGE2 formation by cyclo-oxygenase inhibitors significantly lowers patient mortality and morbidity. However, the pathogenic role of PGE2 in HPS/aBS awaits clarification. Chronic blockade of the Na-K-2Cl co-transporter NKCC2 by diuretics causes symptoms similar to HPS/aBS and provides a useful animal model. In wild-type (WT) mice and in mice lacking distinct PGE2 receptors (EP1-/-, EP2-/-, EP3-/-, and EP4-/-), the effect of chronic furosemide administration (7 d) on urine output, sodium and potassium excretion, and renin secretion was determined. Furthermore, furosemide-induced diuresis and renin activity were analyzed in mice with defective PGI2 receptors (IP-/-). In all animals studied, furosemide stimulated a rise in diuresis and electrolyte excretion. However, this effect was blunted in EP1-/-, EP3-/-, and EP4-/- mice. Compared with WT mice, no difference was observed in EP2-/- and IP-/- mice. The furosemide-induced increase in plasma renin concentration was significantly decreased in EP4-/- mice and to a lesser degree also in IP-/- mice. Pharmacologic inhibition of EP4 receptors in furosemide-treated WT mice with the specific antagonist ONO-AE3-208 mimicked the changes in renin mRNA expression, plasma renin concentration, diuresis, and sodium excretion seen in EP4-/- mice. The GFR in EP4-/- mice was not changed compared with that in WT mice, which indicated that blunted diuresis and salt loss seen in EP4-/- mice were not a consequence of lower GFR. In summary, these findings demonstrate that the EP4 receptor mediates PGE2-induced renin secretion and that EP1, EP3, and EP4 receptors all contribute to enhanced PGE2-mediated salt and water excretion in the HPS/aBS model.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Bartter Syndrome / metabolism*
  • Bartter Syndrome / pathology*
  • Cyclooxygenase Inhibitors / pharmacology
  • Dinoprostone / metabolism*
  • Disease Models, Animal
  • Diuresis
  • Diuretics / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Furosemide / pharmacology
  • Glomerular Filtration Rate
  • K Cl- Cotransporters
  • Kidney Tubules / pathology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Models, Statistical
  • Prostaglandins E / metabolism*
  • RNA, Messenger / metabolism
  • Receptors, Prostaglandin E / metabolism
  • Receptors, Prostaglandin E / physiology*
  • Receptors, Prostaglandin E, EP1 Subtype
  • Receptors, Prostaglandin E, EP3 Subtype
  • Receptors, Prostaglandin E, EP4 Subtype
  • Renin / metabolism
  • Ribonucleases / metabolism
  • Salts / metabolism
  • Salts / pharmacology
  • Sodium / metabolism
  • Sodium Chloride / pharmacology
  • Sodium Chloride, Dietary / pharmacology
  • Sodium-Potassium-Chloride Symporters / metabolism
  • Symporters / antagonists & inhibitors
  • Time Factors

Substances

  • Actins
  • Cyclooxygenase Inhibitors
  • Diuretics
  • Enzyme Inhibitors
  • Prostaglandins E
  • Ptger1 protein, mouse
  • Ptger3 protein, mouse
  • Ptger4 protein, mouse
  • RNA, Messenger
  • Receptors, Prostaglandin E
  • Receptors, Prostaglandin E, EP1 Subtype
  • Receptors, Prostaglandin E, EP3 Subtype
  • Receptors, Prostaglandin E, EP4 Subtype
  • Salts
  • Sodium Chloride, Dietary
  • Sodium-Potassium-Chloride Symporters
  • Symporters
  • Sodium Chloride
  • Furosemide
  • Sodium
  • Ribonucleases
  • Renin
  • Dinoprostone