Human fallopian tubes express prostacyclin (PGI) synthase and cyclooxygenases and synthesize abundant PGI.
Animal studies unequivocally support the indispensable role of prostaglandin (PG) and cyclooxygenase (COX) in ovulation and implantation. Available data also suggest that PG and COX may be important in the transport of embryos. The effects of PGE(2) and PGF(2alpha) on the contractility of human tubal muscle have been studied extensively; the expression of COX in human fallopian tubes was also reported. Despite all these, two fundamentally important questions remained to be answered: 1) which PGs are produced by human fallopian tubes; and 2) which COX isoform(s) is expressed by the fallopian tubes. We used reverse-phase HPLC to study the metabolism of [1-(14)C] arachidonic acid by the fallopian tubes. We found that 6 keto-PGF(1alpha), a stable metabolite of prostacyclin (PGI), and PGE(2) constituted 56% +/- 10% and 35% +/- 10% (mean +/- SEM, four samples), respectively, of total eicosanoids synthesized. Western blot analysis revealed the expression of both COX isoforms. Immunohistochemistry study showed that both COX-1 and -2 were localized to nonciliated epithelia and tubal smooth muscle. In addition, COX-2 was also expressed in ciliated epithelial cells. Western blot analysis revealed the expression of PGI synthase (PGIS) and PGI receptor by fallopian tubes. Immunohistochemistry confirmed the expression of PGIS by luminal epithelia, tubal smooth muscle, vascular endothelial cells, and vascular smooth muscle cells. Iloprost, a PGI analog, inhibited the activities of circular and longitudinal muscles of the fallopian tube. Thus, the fallopian tube expresses both COX isoforms and PGIS. Furthermore, it is a source and a target of PGI. PGI and COX may be important to gamete function, embryo transport, and embryo development.
Huang
Jaou-Chen
JC
Department of Obstetrics and Gynecology, University of Texas Medical School at Houston, Institute of Molecular Medicine and Division of Hematology, Texas 77030, USA. jaou-chen.huang@uth.tmc.edu
Arbab
Farinaz
F
Tumbusch
Katherine J
KJ
Goldsby
Jennifer S
JS
Matijevic-Aleksic
Nena
N
Wu
Kenneth K
KK
D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism; D004847:Epithelial Cells / Q000201:enzymology; D011464:Epoprostenol / Q000096:biosynthesis*; D005187:Fallopian Tubes / Q000201:enzymology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019746:Intramolecular Oxidoreductases / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D008565:Membrane Proteins; D008861:Microsomes / Q000201:enzymology; D009119:Muscle Contraction / Q000502:physiology*; D009130:Muscle, Smooth / Q000502:physiology; D009578:Nitrobenzenes / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D013449:Sulfonamides / Q000494:pharmacology
D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D009578:Nitrobenzenes; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D003577:Cytochrome P-450 Enzyme System; D011464:Epoprostenol; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D019746:Intramolecular Oxidoreductases; C022461:prostacyclin synthetase; D015232:Dinoprostone