Succinic dehydrogenase activity in germinal center macrophages in peripheral lymphoid organs of the rat

Secondary lymphoid follicles in peripheral lymphoid organs (parathymic, mesenteric and inguinal lymph nodes and spleen) from young adult Wistar rats of both sexes were studied. Different numbers of tingible body macrophages containing aldehyde fuchsin-positive cytoplasmic granules of varying size, were present in the germinal centers. An identical staining pattern to that obtained with aldehyde fuchsin in terms of the number, distribution and size of positive cells was seen after staining for succinic dehydrogenase.