URINARY PGE2 IN RATS WITH CHRONIC PARTIAL UNILATERAL URETERAL OBSTRUCTION

Urinary prostaglandin E2 (PGE2) was measured in Munich-Wistar rats with surgically created chronic partial unilateral ureteral obstruction (UUO). Mean values of bladder urine PGE2 were higher in sham than in UUO (24.5 ± 14.4 vs 12.9 ± 8.2 ng/mg creatinine, respectively, P < 0.05). Following diuresis, both ureters were cannulated and urine was collected. PGE2 excretion was increased in sham (66.5 ± 34.4 and 70.1 ± 44.5 ng/mg creatinine, left and right, respectively). But in UUO, the obstructed kidney excreted less PGE2 than the contralateral kidney (32.1 ± 6.0 vs 62.3 ± 40.4 ng/mg creatinine, obstructed vs contralateral, respectively, P = 0.08). PGE2 synthesis was then determined in separated renal medullary and cortical slices. Renal medullary slices from kidneys with severe obstruction synthesized less PGE2 than the contralateral unobstructed side (3.30 ± 1.22 vs 10.52 ± 3.23 ng/mg wet wt-30 min, respectively, P < 0.05) and failed to respond to arachidonic acid stimulation with any significant increase in PGE2 synthesis (3.30 ± 1.22 vs 4.47 ± 1.04 ng/mg wet wt-30 min, baseline vs stimulated). In contrast, contralateral unobstructed kidney slices responded with a significant increase in PGE2 synthesis (10.52 ± 3.23 vs 21.10 ± 2.50 ng/mg wet wt-30 min, baseline vs stimulated, P < 0.05). We conclude that chronic partial UUO in the Munich-Wistar rats resulted in significantly less PGE2 elaboration. © 1991.