Synthesis and transudation of antibody during acute inflammation in the mammary gland

Nonlactating ewes were immunized with a mixture of ovalbumin and tetanus toxoid either in the hind limb, resulting in “priming” of the supramammary lymph node (group L), or in the brisket, resulting in “priming” of the precapsular lymph node (group B). Substantial systemic antibody responses were mounted in both groups. The animals were challenged by intramammary infusion of either tetanus toxoid and lipopolysaccharide (LPS) or ovalbumin and LPS, and changes in the ratios of the two antibody specificities in mammary secretions were monitored for the first 8 h of the resulting acute inflammatory episode. Following challenge with tetanus toxoid and LPS, the ratio of antitetanus toxoid-antiovalbumin in mammary secretion remained close to 1 for the first 6 h postchallenge in both group L and group B. Similarly in animals challenged with ovalbumin and LPS, the ratio of antiovalbumin-antitetanus toxoid in mammary secretion approximated 1 for the first 6 h postchallenge but increased sharply in both groups between 6 and 8 h postchallenge. Measurement of antibody in efferent supramammary lymph suggested that cells in the supramammary lymph node synthesized significant quantities of specific antibody to the infused antigen during the 8-h inflammatory episode.