COX-2 compensation in the uterus of COX-1 deficient mice during the pre-implantation period.
Prostaglandins (PGs) produced by cyclooxygenase (COX) participate in many aspects of female reproduction. The two isoforms of cyclooxygenase, COX-1 and COX-2, have distinct expression patterns in the mouse uterus during the peri-implantation period and suggest their independent contribution to uterine PGs. Using wild type and COX-1(-/-) mice, we examined the role of COX-1-derived PGs on day 4 of pregnancy, when its expression is maximal. Uterine vascular permeability was measured by 125I-labeled bovine serum albumin (BSA) uptake, and PG content was measured by gas chromatography-mass spectrometry. Vascular permeability and PG concentrations were reduced in COX-1(-/-) mice, but by less than the expected amount. After ovariectomy, uterine vascular permeability declined in both groups, but returned to baseline in wild type and was exaggerated in COX-1(-/-) females after treatment with ovarian steroids. Most importantly, COX-1(-/-) uteri displayed COX-2 expression on the morning of day 4, when COX-2 is normally absent. This hybridization pattern resembles the native expression of COX-1, and may partially offset the loss of COX-1-derived PGs. These data indicate that COX-1-derived PGs are important during uterine preparation for implantation, and that COX-2 compensation occurs in the absence of COX-1.
Reese
J
J
Department of Pediatrics, University of Kansas Medical Center, Kansas City 66160-7338, USA. jreese@kumc.edu
Brown
N
N
Paria
B C
BC
Morrow
J
J
Dey
S K
SK
D000818:Animals; D002417:Cattle; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D007527:Isoenzymes / Q000172:deficiency* / Q000502:physiology*; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D011247:Pregnancy; D011451:Prostaglandin-Endoperoxide Synthases / Q000172:deficiency* / Q000502:physiology*; D014599:Uterus / Q000502:physiology*
D007527:Isoenzymes; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496512:Ptgs1 protein, mouse