Migration of human lymphocytes. II. Variation of lymphocyte distribution

Variations in the distribution of 51Cr-labelled human lymphocytes from several donors and from one donor on several occasions have been determined after their injection into carbon-treated mice and reasons for the variation discussed. Natural alteration of the lymphocyte surface (leukaemic lymphocytes) or induced change (trypsin-treatment) reduced lymph node localisation as did treatment with formalin, sodium azide and antilymphocyte globulin. We have concluded that the presence of radioactivity in the lymph nodes is due to the presence of viable, metabolically active lymphocytes with normal surfaces capable of interacting with the endothelium of the post-capillary venules.