Origin and molecular size of immunoglobulin-A in the mesenteric lymph of the dog.

Abstract

Samples of mesenteric lymph, thoracic duct lymph or lymph of mixed (hepatic and intestinal) origin from adult dogs were compared with serum from the same animals with regard to the concentrations of different proteins, particularly IgA, IgM, IgG1, IgG2ab and IgG2c. In all samples the lymph to serum ratio for IgA was found considerably to exceed the corresponding ratios for the other immunoglobulins. From these data it was calculated that from 60 per cent to over 95 per cent of the IgA in mesenteric lymph was produced by the plasma cells of the intestinal mucosa, and that the latter significantly contributed to the pool of circulating IgA.