title: Stimulation of rabbit renal PGE2 biosynthesis by dietary sodium restriction.
abstract: Immunoreactive prostaglandin E2 (PGE2) was measured in slices of renal papilla (P), outer medulla (OM), and cortex (C) before and after 30 min of incubation (biosynthesis) in Krebs-Ringer HCO3- buffer in rabbits on low (LS), normal (NS), and high (HS) sodium diets. The 24-h urine PGE2 was also measured daily for 10 days prior to incubation. Daily urine PGE2 was significantly higher (911 +/- 54 ng) in LS, decreasing to 605 +/- 33 at NS, and 558 +/- 48 ng at HS, Initial slice PGE2 was highest in P at LS (35.5 +/- 5.1 MICROGRAMS/G), 5.1 microgram/g), decreasing to 16.9 +/- 1.3 at NS and 18.0 +/- 2.6 micrograms/g at HS. Similar patterns were observed in OM and C, which were quantitatively much lower. PGE2 biosynthesis was highest at LS (P, 139 +/- 21; OM, 58.8 +/- 5.1; C, 0.20 +/- 0.05 micrograms.G-1.30 Min-1) and lowest at HS (P, 58.9 +/- 7.4; OM, 11.8 +/- 3.1; C, 0.07 +/- 0.01 micrograms.g-1.30 min-1). Although PGE2 concentration was higher in P than in OM, the percent increase in OM PGE2 biosynthesis on LS was 3--4 times greater than in P. Since OM is 28% and P is 2% of total renal mass, these results indicate that LS markedly stimulates PGE2 biosynthesis primarily in OM and to a lesser extent in P and C, findings suggesting an important role for OM PGE2 in the renal adaptation to sodium deprivation.
mesh_terms: D000818:Animals; D004039:Diet, Sodium-Restricted; D007672:Kidney Cortex / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D008297:Male; D010100:Oxygen / Q000502:physiology; D011458:Prostaglandins E / Q000378:metabolism* / Q000652:urine; D011817:Rabbits
chemical_list: D011458:Prostaglandins E; D010100:Oxygen