Immunohistochemical studies of the local immune system in the reproductive tract of the sow.

Tissues from the reproductive tract of sexually mature female pigs were examined histologically using antisera to porcine IgG, IgA and IgM coupled to horseradish peroxidase. Plasma cells synthesising all three immunoglobulins were found in all regions of the tract, with IgA-producing cells as the predominant type. Larger numbers of plasma cells were found in the lower region of the tract and the number of plasma cells was raised during oestrous. Intercellular staining of immunoglobulins was also observed and was also under hormonal influence. The results indicate the presence of a local mucosal immune system in the female reproductive tract of the pig.