| Abstract: | Rats were immunized with human serum albumin (HSA) by a single intragastric administration of 200 mg of HSA. Two weeks later their capacity to absorb a similar intragastric test dose of HSA was found to be greatly impaired, the concentrations of HSA in mesenteric venous serum having been reduced to 33 %, 25 % and 60 % of those in similarly tested but unprimed animals, respectively 1, 2 and 3 hours after the intragastric test dose. Rats given antigen (HSA) together with intestinal secretions from intragastric immunized rats also showed a striking decrease in intestinal absorption of a test dose, compared to controls given the antigen together with nonimmune intestinal secretions. From these data it is concluded that local immunization of the gut impairs its capacity to absorb the corresponding antigen, and that this effect is largely due to the failure to absorb antigen bound to secretory antibodies. |
