Expression and distribution of cyclooxygenase-2 in human ovary during follicular development.
Prostaglandins play important roles for oocyte maturation and follicular rupture. Cyclooxygenase-2 (COX-2), an inducible isoform of a prostaglandin metabolic enzyme, is essential for the timed production of prostaglandins in the ovary. The aim of the present study is to examine expression and distribution of COX-2 in human ovarian follicles at each of the maturation stages. Immunohistochemical staining shows that COX-2 is expressed in the granulosa cell layer of secondary and developing follicles, but is not detected in primary and Graafian follicles. Western blotting analysis revealed the existence of COX-2 in periovulatory follicular fluid at a mean concentration of 5.6 +/- 0.6 ng/ml. COX-2 might begin to be produced at the secondary follicle stage, and once a follicle reaches the Graafian follicle stage, the production of this enzyme is stopped. After exposure to luteinizing hormone (LH) surge, follicles might resume production of COX-2, and this is secreted into the follicular fluid.
Tokuyama
Osamu
O
Department of Obstetrics and Gynecology, Osaka City University Medical School, Japan. otoku@med.osaka-cu.ac.jp
Nakamura
Yoshiro
Y
Musoh
Ayako
A
Honda
Ken-ichi
K
Ozaki
Koji
K
Ishiko
Osamu
O
D000328:Adult; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000502:physiology; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis* / Q000502:physiology; D008565:Membrane Proteins; D006080:Ovarian Follicle / Q000502:physiology*; D010053:Ovary / Q000201:enzymology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis* / Q000502:physiology
D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone