IgG isolated from aborted bovine fetuses was found to be directed not only to a diaplacental infectious agent but, in half of the cases, also to the site of infection, i.e. the placental tissue. The techniques used were immunohistochemistry and agarose immunoelectrophoresis. These findings suggest a hitherto unrecognized pathological mechanism of abortion.
Key words Abortion - bovine - IgG - immunological response