Prostacyclin increases distal tubule HCO3 secretion in the rat

Am J Physiol. 1996 Dec;271(6 Pt 2):F1183-92. doi: 10.1152/ajprenal.1996.271.6.F1183.


We examined whether prostacyclin (PGI2), a prostaglandin synthesized in the renal cortex that increases adenosine 3',5'-cyclic monophosphate levels in distal nephron epithelia, mediates increased HCO3 secretion in in vivo perfused distal tubules of anesthetized rats given dietary HCO3. Animals eating a minimum electrolyte diet given 80 mM NaHCO3 drinking solution increased urine excretion of 6-keto-PGF1 alpha, a PGI2 metabolite, by 2.6 +/- 0.3-fold compared with those drinking distilled H2O. NaHCO3 animals infused with indomethacin to inhibit PGI2 synthesis had lower HCO3 secretion than those without indomethacin (-8.9 +/- 0.9 vs. -18.7 +/- 1.8, P < 0.01). By contrast, NaHCO3 animals infused with both PGI2 and indomethacin had higher HCO3 secretion than those given indomethacin alone (-16.0 +/- 1.5, P < 0.02 vs. indomethacin group). HCO3 secretion was not different between controls with and without indomethacin but was higher in the PGI2 + indomethacin compared with the indomethacin alone controls (-11.2 +/- 1.2 vs. -4.5 +/- 0.5, P < 0.01). The data show that PGI2 increases distal tubule HCO3 secretion in rats and suggest that this agent contributes to the increased distal tubule HCO3 secretion induced by dietary HCO3.

Publication types

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

MeSH terms

  • Animals
  • Bicarbonates / metabolism*
  • Body Weight
  • Diet
  • Epoprostenol / metabolism
  • Epoprostenol / pharmacology*
  • Female
  • Kidney Tubules, Distal / drug effects*
  • Kidney Tubules, Distal / metabolism*
  • Male
  • Punctures
  • Rats
  • Rats, Inbred Strains
  • Sodium Bicarbonate / pharmacology
  • Urine / chemistry


  • Bicarbonates
  • Sodium Bicarbonate
  • Epoprostenol