Studies of the pathogenetic role of humoral antibodies reacting with subcellular organ antigens. I. Active immunization of rabbits with rat-organ antigens.

Rat organ homogenates were fractionated by differential centrifugation and the fractions were incorporated into incomplete Freund's adjuvant and administered intramuscularly to rabbits. Gel-diffusion precipitin and complement-fixation tests showed the development of antibodies which reacted with rat, and in lower titres with rabbit organ fractions. The rabbit antisera to liver and kidney fractions reacted with preparations of both these organs, and antisera to liver fractions (nuclei, mitochondria and supernate) reacted with all three of these preparations. Hepatic lesions were observed in those animals which developed antibodies shown capable of reacting with liver tissue constituents. These changes were most pronounced in rabbits immunized with liver mitochondria, in which inflammatory changes and fibrosis were related to the biliary ductules, and in those immunized with liver nuclear or kidney mitochondrial fractions, in which the changes appeared mainly around the larger interlobular hepatic ducts. Changes occurred also in the kidneys, but were observed also in control animals injected with normal rat serum.