Comparative aspects of the transport of immunoglobulin A from blood to bile.

Polymeric and monomeric human IgA were isolated from the sera of patients with IgA myeloma; rat IgA polymer, monomer and IgG2 were isolated from the ascitic fluid or sera of Lou/Wsl rats bearing appropriate myelomata. The purified Ig preparations were labelled with 125I and injected intravenously into rats, rabbits, guinea-pigs or sheep that had had a cannula inserted into the common bile duct so that their bile could be collected quantitatively. Rats and rabbits transported 30% of the injected dose of both IgA polymers, but no other type of immunoglobulin, from blood to bile within 5--7 h. Sheep and guinea-pigs were unable to transport any of the immunoglobulin preparations from blood to bile, even though the injected material remained circulating in the blood.