Takashi Shoda (1), Ko Hatanaka (2), Maki Saito (2), Masataka Majima (2), Michiko Ogino (2), Yoshiteru Harada (2), Masahiro Nishijima (1), Makoto Katori (2) and Shozo Yamamoto (3)
(1) Department of Obstetrics and Gynecology and (2) Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa 228, Japan
(3) Department of Biochemistry, Tokushima University School of Medicine, Tokushima 770, Japan
Abstract: We investigated the induction of cyclooxygenase (COX) in rat endometrium during the estrus cycle. The estrus cycle was divided into five stages (proestrus, estrus, diestrus-1, diestrus-2, diestrus-3) by cytological observation of vaginal smears. COX-1 was detected in the endometrium during all five stages of the estrus cycle. In contrast, COX-2 in the endometrium was detectable only in three stages (diestrus-3, proestrus, estrus) and showed a peak at diestrus-3, coinciding with the peak in serum estradiol level, suggesting the estradiol-dependent induction of COX-2.
Keywords: Cyclooxygenase, Estradiol, Endometrium