Studies of the transport of polyclonal IgA antibody from blood to bile in rats.

Bile or thoracic duct lymph, collected from rats 7-9 days after suspensions of B. abortus, S. typhi or SRBC had been injected into the Peyer's patches, contained high titres of specific agglutinins. Samples of these fluids were injected i.v. into unimmunized, syngeneic recipients and the partitioning between blood and bile of the injected antibodies was studied and found to depend on the source and class of the antibody. IgA antibodies from lymph plasma disappeared rapidly from the recipients' blood and half of the dose was recovered in the bile within 2 h of its injection. IgA antibodies which had been collected from bile and so had previously traversed the liver and acquired secretory component, appeared in the recipients' bile much less rapidly so that less than half of the dose entered the bile over a period of 40 h. Passively administered IgG antibodies did not enter the recipients' bile to any significant extent and specific haemolysins never appeared in the bile after either passive or active immunization.