[Comparison between the way of intravenous administration of flagellin from Salmonella typhosa to the margial vein in the ear and into the mesenteric superior vein. Preliminary note].

Rabbits receiving three injections of PFA intravenously in ear, after that first treatment gave a weak antibody response, after the second one a rapid and copious increase of agglutination titre; the third injection induced a very small increase. In rabbits injected with PFA in superior mesenteric vein the first injection produced a little effect, the second induced a little effect too; the third injection performed in auricular vein, gave a substancial rapid and copious antibody response. This behaviour is similar to that obtained after the second injection in the first set of experiments. The PFA injected two times in mesenteric vein caused certainly a massive phagocytosis of antigen by Kupffer cells. Nevertheless this copious phagocytosis can exercise only an action of "priming", not a response of secondary type. For this purpose it is necessary an injection in the ear vein to provoke a direct intervention of lymphonodal reticular phagocytes. The phenomenon can be related to the proteic nature of the antigen.