Prostacyclin increases distal tubule hco3 secretion in the rat
.
Wesson, Donald E.
Texas Tech University Health Sciences Center, Lubbock, TX and
Veterans Affairs Medical Center, Baylor College of Medicine, Houston,
TX
APStracts 3:0162F, 1996.
Wesson, Donald E. Prostacyclin Increases Distal Tubule HCO3 Secretion
In The Rat. We examined if prostacyclin (PGI2), a prostaglandin
synthesized in the renal cortex that increases cAMP 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(, a PGI2
metabolite, by 2.6 ( 0.3-fold compared to 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 pmol/mm.min, 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 to 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.
Received 9 April 1996; accepted in final form 29 August 1996.
APS Manuscript Number F110-6.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996