Effect of purine derivatives on regeneration and immunologic reactivity in animals

The effect of azathioprine and KI-7 (a new purine derivative) on immunogenesis and regeneration in mammals was compared. KI-7, which is less toxic than azathioprine, was shown to inhibit antibody synthesis against sheep's red blood cells in mice if injected on the day before or the day of immunization, and also to prolong the life of skin allographs in rabbits considerably compared with the control. It was also shown that during inhibition of the system of immunogenesis, regeneration of the liver still takes place in rats, but the relationship between proliferation and cellular hypertrophy differs from that during regeneration under ordinary conditions and depends on the immunodepressant used. for instance, unlike azathioprine, KI-7 not only did not inhibit mitotic activity of the regenerating liver, but actually stimulated it a little.