Lymphatic drainage of the spleen

¹ Department of Physiology, Medical College of Georgia, Augusta, Georgia

The spleens of a series of rats, mice, and guinea pigs were observed by the Knisely transillumination technique with the circulation undisturbed. An injection into the parenchyma of the spleen usually entered a vein and was distributed to the venous sinuses. India ink did not go through the walls of the sinuses but was taken up by phagocytes in these walls. Patent blue dye filled the vessels and immediately diffused into the interstitial space. It was quickly and clearly visible in structures that were taken to be the lymph capillaries and appeared about 5 min later in lymph channels in the same sector of the hilus as the injection. Contractions of the lymphatic wall helped move the dyed lymph into the splenic lymph node and on into the cisterna. On numerous occasions the injecting needle entered a parenchymal lymph space and the injected material appeared immediately and in high concentration in a hilar lymph channel. Only after trauma did red cells or India ink leave the blood stream to appear in the hilar lymph channels. These observations support the theory that the splenic circulation is closed and that as the cells concentrate in the spleen, the fluid drains off through lymphatics. Physical and morphological considerations are advanced which also favor the idea that the splenic circulation is closed.