The effect of prostaglandin-synthesis stimulation and blockade on sodium excretion at a fixed renal perfusion pressure.
PGE synthesis was increased by an infusion of AA and decreased with indomethacin or carpofen. Intrarenal infusions of arachidonate increased RBF from 222 +/- 37 to 275 +/- 51 ml/min (p less than 0.05) and UNaV from 85 +/- 23 to 121 +/- 32 muEq/min (p less than 0.05), with renal vein PGE increasing from 0.41 +/- 0.08 to 1.81 +/- 0.69 ng/ml (p less than 0.05). However, when renal perfusion pressure was reduced and maintained constant at 82 +/- 4 mm Hg during the AA infusion, RBF, and UNaV did not change, 185 +/- 26 vs. 178 +/- 21 ml/min and 10 +/- 3 vs 8 +/- 3 muEq/min, respectively, although renal vein PGE increased from 0.8 +/- 0.2 to 1.95 +/- 0.52 ng/ml (p less than 0.05. During Pl with indomethacin, 2 mg/kg, RBF fell from 210 +/- 27 to 120 +/- 16 ml/min (p less than 0.05), and UNaV diminished from 39 +/- 6 to 22 +/- 10 muEq/min (p less than 0.05), as renal vein PGE decreased from 0.37 +/- 0.04 to 0.19 +/- 0.03 ng/ml (p less than 0.05). When renal perfusion pressure was reduced and maintained constant at 90 +/- 2 mm Hg, renal vein PGE fell from 0.72 +/- 0.29 to 0.20 +/- 0.08 ng/ml (p less than 0.05), whereas RBF and UNaV were unchanged during Pl, 172 +/- 20 vs. 166 +/- 30 and 33 +/- 15 vs. 28 +/- 11, respectively. The results indicate that the change in sodium excretion with variation in prostaglandin synthesis is best explained by concomitant changes in RBF.
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001095:Arachidonic Acids / Q000494:pharmacology*; D001783:Blood Flow Velocity; D002227:Carbazoles / Q000494:pharmacology; D004285:Dogs; D005919:Glomerular Filtration Rate; D007213:Indomethacin / Q000494:pharmacology*; D010477:Perfusion; D011458:Prostaglandins E / Q000096:biosynthesis*; D012964:Sodium / Q000378:metabolism*; D014556:Urine
D000893:Anti-Inflammatory Agents; D001095:Arachidonic Acids; D002227:Carbazoles; D011458:Prostaglandins E; D012964:Sodium; D007213:Indomethacin