Distributions of immunoglobulin-containing cells in alimentary tract, spleen, and mesenteric lymph node of the pig demonstrated by peroxidase-conjugated antiserums to porcine immunoglobulins G, A, and M.

Peroxidase-conjugated antibody to porcine immunoglobulins A, G, and M were used in a light microscope study of the distribution of immunoglobulins and immunoglobulin-containing cells in alimentary tract, spleen, and mesenteric lymph node of the pig. Largest populations of plasma cells staining for each of the 3 immunoglobulin classes were demonstrated in the lamina propria of the intestinal tract. Immunoglobulin A cells were most numerous, and immunoglobulin A and M cells each outnumbered immunoglobulin G cells which were, however, present in considerable numbers. Both immunoglobulins A and M were demonstrated in intestinal crypt epithelial cells, indicating they have similar intracellular secretion pathways. Porcine spleen and mesenteric lymph node seem to have a minor role in immunoglobulin synthesis.