AJP - Renal Physiology, Vol 250, Issue 1 58-F65, Copyright © 1986 by American Physiological Society
PGI2 synthesis and excretion in dog kidney: evidence for renal PG compartmentalization
R. M. Boyd, A. Nasjletti, P. M. Heerdt and P. G. Baer
To assess the concept of compartmentalization of renal prostaglandins (PG),
we compared entry of PGE2 and the PGI2 metabolite 6-keto-PGF1 alpha into
the renal vascular and tubular compartments, in sodium
pentobarbital-anesthetized dogs. Renal arterial 6-keto-PGF1 alpha infusion
increased both renal venous and urinary 6-keto-PGF1 alpha outflow. In
contrast, renal arterial infusion of arachidonic acid (AA) or bradykinin
(BK) increased renal venous 6-keto-PGF1 alpha outflow but had no effect on
its urinary outflow. Both urinary and renal venous PGE2 outflows increased
during AA or BK infusion. Ureteral stopped-flow studies revealed no
postglomerular 6-keto-PGF1 alpha entry into tubular fluid. During renal
arterial infusion of [3H]PGI2 and inulin, first-pass 3H clearance was 40%
of inulin clearance; 35% of urinary 3H was 6-keto-PGF1 alpha, and two other
urinary metabolites were found. During renal arterial infusion of
[3H]6-keto-PGF1 alpha and inulin, first-pass 3H clearance was 150% of
inulin clearance; 75% of urinary 3H was 6-keto-PGF1 alpha, and only one
other metabolite was found. We conclude that in the dog PGE2 synthesized in
the kidney enters directly into both the renal vascular and tubular
compartments, but 6-keto-PGF1 alpha of renal origin enters directly into
only the renal vascular compartment.
