The Zone of Localization of Antibodies. XIII. The in Vivo Localization of Anti-Liver-Blood-Vessel Antibodies in the Rat

Abstract
Antisera were prepared in rabbits by injecting rat liver blood vessels. The localization properties of the antibodies were investigated by following the in vivo disposition of radioactivity from the radioiodinated globulin fractions of the sera. Kidney-, liver-, and lung-localizing antibodies could be demonstrated in the serum. When the radioiodinated antibodies which had localized in liver, kidney and lung were eluted at pH 11 and reinjected into recipient rats, the pattern of localization was determined by the organ from which the material was isolated. The localization favored the organ of initial fixation. Radioiodinated normal serum proteins are likewise fractionated in vivo by the liver, kidney and lung when injected into rats. Here, the eluted radioactivity obtained from the liver, kidney and lung also returned preferentially to the organ of initial localization, but to a lower extent than shown by localizing antisera. This fractionation of normal serum proteins was attributed to the ability of the various organs to fix selectively different proteins. Purification of antibodies in vitro was carried out by adsorbing radioiodinated anti-liver serum with liver blood vessel antigen and then eluting the adsorbed radioactivity at pH 11. These preparations showed increased localization in the liver and kidney while no increased localization was observed in the controls.