Effects of 6-Mercaptopurine on Susceptibility of Guinea Pigs to Experimental Allergic Encephalomyelitis.

Abstract

Guinea pigs injected with both antigen (homologous brain plus Freund''s adjuvant) and 6-mercaptopurine (6-MP) showed a slightly higher incidence of urinary incontinence and rapid weight loss but no definite difference in incidence of paralysis than did animals given only antigen; no change in mean day of onset was evident. While antigen alone increased the number of circulating neutrophils (but not of lymphocytes), antigen and 6-MP together and 6-MP alone produced similar leukocyte patterns delayed but marked neutropenia, and a marked rapid decline in lymphocytes. In animals given both 6-MP and antigen, a left shift in the Arneth Index of neutrophils occurred, in spite of the reduced level of circulating neutrophils.