Migration of macrophages to the thymus after cyclophosphamide.

The thymus macrophages behaviour during cyclophosphamide induced thymic lympholysis has been studied in the mouse previously injected with trypan blue. In these conditions a significant increase of the number of macrophages in the subcapsular zone of the cortical layer of the thymus has been observed. Moreover some macrophages of the cortical layer presented lymphocyte debris in their cytoplasm in addition to particles of trypan blue. Possible implications of these findings are discussed; a migration of macrophages into the thymus from elsewhere is suggested.