Immunoglobulins in the mouse uterus during the oestrous cycle

Abstract

The distribution of IgA, IgG and IgM was studied by an immunoperoxidase technique on sections of mouse uteri at each stage of the estrous cycle. Staining for IgG and IgA was highest at proestrus, declined at estrus and was very low during the other stages. At proestrus IgG was found throughout the stroma, in the uterine lumen and in 10% of glandular lumina; very few IgG-containing plasma cells were present. At proestrus, IgA was found in the uterine lumen, and in most of the uterine glands, both in the lumen and in the epithelium; little IgA was present in the stroma. IgA-plasma cells were detected at each stage of the cycle and were particularly numerous at proestrus and estrus. IgA could be secreted locally from plasma cells into the uterine gland through the glandular epithelium, but IgG enters the stroma from the local capillaries. The obvious increase in IgG and IgA secretion at proestrus, when plasma estradiol levels are highest, supports the hypothesis that, during the estrous cycle, the humoral immune response is regulated in the uterus by ovarian hormones.