In vivo toxicity to lymphoid tissue by 2'-deoxycoformycin

The enzyme adenosine deaminase has an essential role in lymphocyte metabolism. To examine the in vivo effects of inhibition of this enzyme healthy BDF1 mice were injected intraperitoneally with 2'-deoxycoformycin, a stoichiometric tight-binding inhibitor of adenosine deaminase. Of the treated animals, 20% died of overwhelming infection, and histopathological examination of these, and surviving animals sacrificed 10 days following treatment indicated a selective toxicity to lymphoid cells. No toxicity to tissues other than the lymphoid system was observed, which is consistent with the hypothesis that 2'-deoxycoformycin offers a new and selective approach to the treatment of lymphoid malignancies.