Localization of proliferating cells in lymphatic tissues triggered by dextran sulfate

Mice were injected with dextran sulfate in the presence or absence of various amounts of sheep red blood cells. The incorporation of thymidine into the proliferating cells of spleen, lymph nodes and thymus was investigated using autoradiographic and histologic techniques. Dextran sulfate triggered selective proliferation of cells localized in the marginal zone of the white pulp of the spleen. The uptake of colloid carbon particles was also enhanced by dextran sulfate in this area of the spleen. The results are consistent with the suggestion that dextran sulfate triggers proliferation of non-thymus-derived cells probably a sub-population of B-lymphocytes and activates phagocytic cells.