Novel method for following lymphocyte traffic in mice using [3H]glycerol labeling

We describe a new method based on radioactive metabolic labeling with [3H]glycerol to study the lymphocyte trafficking in mice. Lymphocyte labeling with [3H]glycerol is time- and dose-dependent. Radioactive leaking is less significant than in 51Cr-labeled cells. Lymphocytes, labeled with [3H]glycerol, with 51Cr, or with both labels together show the same pattern of homing to Peyer's patches (PP), peripheral and mesenteric lymph nodes and spleen and homing shows the expected dependence on pertussis toxin (PTX)-sensitive signaling, suggesting that the labeling procedure with [3H]glycerol does not affect lymphocyte trafficking properties. Tissue accumulation can be readily assessed by scintillation counting of sonicated samples obtained after perfusion of the vasculature with saline to remove blood. Moreover, we show that cell labeling with [3H]glycerol provides improved sensitivity in assessing the accumulation of small numbers of labeled cells in non-lymphoid organs, and permits identification of homed leukocytes in histologic sections.