Abstract
Direct immunofluorescent techniques are utilized to identify the type of infiltrating immunoglobulin in cells of the mature female mammary gland before menopause.
In the average normal premenopausal breast, there are some immunoglobulin-containing cells infiltrating the intra- and interlobular stroma. They are predominantly IgA-containing cells, some are IgM-containing cells, and only a few are IgG-containing cells. Some secretory IgA and IgM immunoglobulins are also found in the apical portion of the acinar epithelial cells, but no IgG is detected.
In the lactating mammary gland, the immunoglobulins, chiefly secretory IgA and IgM, are accumulated in the acinar epithelial cells and secreted into the lumen.
Our present studies prove that the antibodies in mother's milk and colostrum are selectively secreted by IgA- and IgM-containing cells in the mammary glands, but they are probably carried by the lymphatics.
