Localization of Anti-Rat Kidney Antibodies in New-Born Rats. ∗

Summary

Rabbit antibodies against adult rat kidney were found to be fixed in the kidneys of new-born rats. Since new-born rats do not develop clinical disease when injected with anti-rat kidney antibodies, this suggests either that the antigens giving rise to cytotoxic antibodies are not present at this early date or the new-born rats are deficient in complement. Six weeks after new-born rats are so injected they still have the rabbit globulin (antibody) in the glomeruli. However, rabbit globulin was demonstrated in the glomeruli on the medullary side of the cortex and not in those of the periphery indicating that new glomeruli in the peripheral region become functional as the animal matures. The increase in functional glomeruli may be the reason for the observation that new-born rats injected with anti-rat kidney serum do not develop clinical disease.