Expression of Nitric Oxide Synthase in the Endometrium During the Menstrual Cycle. |
I O Song, S R Hong, S J Hong, J H Song, K J Yoo, E C Baik |
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Abstract |
OBJECTIVE This study was designed to determine the expression of nitric oxide synthase [NOS] isoforms in the endometrium of fertile women and to evaluate their cyclic changes during the menstrual cycle. METHODS: The expression of NOS isoforms was examined by immunohistochemistry and image analysis in endometrial tissues of 30 fertile women according to their menstrual cycles. RESULTS: The expression of endothelial NOS [eNOS] and inducible NOS [iNOS] was observed in the endometrium. However, the expression of neuronal NOS [bNOS] wasn`t detected. The mean staining intensities of eNOS and iNOS in glandular epithelium was significantly stronger than that in stromal cells. Cyclic changes of eNOS and iNOS expression were also noted in the endometrium. The mean staining intensities of eNOS and iNOS in endometrium of the secretory phase was significantly stronger than that of the proliferative phase. And the mean staining intensities of eNOS and iNOS in endometrium of the late secretory phase was stronger tendency than that of the mid secretory phase. CONCLUSIONS: This study demonstrated that the expression of eNOS and iNOS was changed in phase dependent manner during the menstrual cycle, implying a physiologic role for nitric oxide in the local control of endometrial function. The strong expression of eNOS and iNOS in endometrium of the late secretory phase suggested that NO may play a role in the process of menstruation. |
Key Words:
Endometrium, eNOS, iNOS, Menstrual cycles, Immunohistochemistry, immage analysis |
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