[Foreign proteins in the blood and lymph after oral administration. Giant molecular foreign proteins in the blood and lymph of adult animals and men and their biological effectiveness after enteral administration].

With isotopic and immunological methods it could be demonstrated that: 1. Rabbit- and horse-proteins can be absorbed from the gut into blood and lymph of rats and dogs in highmolecular form. 2. The highmolecular part after the passage of the intestinal wall was calculated between 5 and 20%. 3. The increase of the lymphocytotoxicity in the lymph of rats from 1:2 to 1:16 after enteral application of horse-antihuman-lymphocyte-gammaglobulin indicates the biological activity of the protein after the penetration through the gut. Furthermore the immunosuppressive effect of ALS after oral application could be demonstrated on the survival time of allogeneic skin transplants. A significant lymphopenia could be induced in dogs after the oral application of horse-antidog-gammaglobulin. From these findings far reaching consequences must be drawn concerning nutritional and immunological aspects. By the enteral absorption of proteins for example a natural tolerance must be induced which is broken in food allergies. Furthermore it is conceivable that the immunocompetent cells of the gastro-intestinal tract can be manipulated for the purpose of immunization or desensibilization within therapeutical programs of prophylactic medicine.