ABSTRACT
Objective To study the distribution and changes of three NOS isoforms in mouse uterus during reproductive stage and understand the possible physiological regulatory roles of endogenous NO in reproduction. Methods Immunohistochemisty and colorimetry were used. Results During reproductive stage, nNOS had a relatively stable expresstion in mouse uterus. Numerous positive cells mainly distributed in endometrial epithelium, endometrial stroma, glandular epithelium, vascular endothelium and smooth muscle. In the middle stage of pregnancy,eNOS had a significantly increased expresstion in mouse uterus. Strongly positive staining was observed in decidual epithelium, glandular epithelium and vascular endothelium. During early stage of pregnancy, iNOS had a relatively stronger expresstion in mouse uterus. Positve materia mainly located in smooth muscle, vascular endothelium, glandular epithelium and endometrial stromal cells. However, during estrus, the staining of iNOS in mouse uterus was negative. Moreover, the levels of NO in mouse serum during reproductive period were measured.Conclution During reproductive stage, three NOS isofoms may act dependently and independently. Endogenous NO may have physiological regulatory roles to estrogenicity, embryo implantation, maintaining the quiescence of the uterus before patrition and tissue remodelling after patrition of mice.\;[