Effects of specific inhibition of cyclooxygenase-2 on sodium balance, hemodynamics, and vasoactive eicosanoids.
Conventional nonsteroidal anti-inflammatory drugs inhibit both cyclooxygenase (Cox) isoforms (Cox-1 and Cox-2) and may be associated with nephrotoxicity. The present study was undertaken to assess the renal effects of the specific Cox-2 inhibitor, MK-966. Healthy older adults (n = 36) were admitted to a clinical research unit, placed on a fixed sodium intake, and randomized under double-blind conditions to receive the specific Cox-2 inhibitor, MK-966 (50 mg every day), a nonspecific Cox-1/Cox-2 inhibitor, indomethacin (50 mg t.i.d.), or placebo for 2 weeks. All treatments were well tolerated. Both active regimens were associated with a transient but significant decline in urinary sodium excretion during the first 72 h of treatment. Blood pressure and body weight did not change significantly in any group. The glomerular filtration rate (GFR) was decreased by indomethacin but was not changed significantly by MK-966 treatment. Thromboxane biosynthesis by platelets was inhibited by indomethacin only. The urinary excretion of the prostacyclin metabolite 2,3-dinor-6-keto prostaglandin F1alpha was decreased by both MK-966 and indomethacin and was unchanged by placebo. Cox-2 may play a role in the systemic biosynthesis of prostacyclin in healthy humans. Selective inhibition of Cox-2 by MK-966 caused a clinically insignificant and transient retention of sodium, but no depression of GFR. Inhibition of both Cox isoforms by indomethacin caused transient sodium retention and a decline in GFR. Our data suggest that acute sodium retention by nonsteroidal anti-inflammatory drugs in healthy elderly subjects is mediated by the inhibition of Cox-2, whereas depression of GFR is due to inhibition of Cox-1.
Catella-Lawson
F
F
University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania, USA. francesca@spirit.GCRC.upenn.edu
McAdam
B
B
Morrison
B W
BW
Kapoor
S
S
Kujubu
D
D
Antes
L
L
Lasseter
K C
KC
Quan
H
H
Gertz
B J
BJ
FitzGerald
G A
GA
D015121:6-Ketoprostaglandin F1 alpha / Q000031:analogs & derivatives / Q000097:blood; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000633:toxicity*; D004311:Double-Blind Method; D015777:Eicosanoids / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007213:Indomethacin / Q000633:toxicity; D007527:Isoenzymes / Q000378:metabolism*; D007783:Lactones; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism* / Q000652:urine; D013450:Sulfones; D013929:Thromboxane B2 / Q000031:analogs & derivatives / Q000097:blood / Q000652:urine; D014882:Water-Electrolyte Balance / Q000187:drug effects*
D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D015777:Eicosanoids; D007527:Isoenzymes; D007783:Lactones; D008565:Membrane Proteins; D013450:Sulfones; C116926:rofecoxib; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; C028290:2,3-dinor-6-ketoprostaglandin F1alpha; C049235:11-dehydro-thromboxane B2; D012964:Sodium; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D007213:Indomethacin