The pathway of nucleated erythrocytes introduced into the splenic artery.

Abstract

Erythrocytes of the domestic fowl, washed free from plasma, were suspended in salt solution, one part in twenty. This suspension was then injected through a fine glass cannula into one of the short gastric branches of the splenic artery of a rabbit, under ether anesthesia. One minute after beginning the injection a portion of spleen at one end was clamped off, excised and placed in Helly's fixing solution for histological study. After two minutes a second sample was taken. After fifteen minutes the remainder of the spleen was perfused through the original cannula, first with a little salt solution and then with Helly's fixing solution, until the spleen became firm and yellowish in color.

Histological study of the one-minute sample showed abundant avian erythrocytes in the spleen pulp of the marginal zone of the Malpighian corpuscles with relatively less cells of this type in the spleen sinuses. At two minutes the relationship was similar but the number of nucleated erythrocytes in the sinuses and in the pulp at a distance from the Malpighian corpuscles had increased. In the last specimen, perfused with fixing solution at the end of fifteen minutes, the distension and perfect fixation permit a clear view of the intimate structural relationships. Here one sees the foreign blood cells in the pulp of the marginal zone and of the pulp cords but also in the interior of the sinuses. Some of them have already been ingested by phagocytic cells.

These observations are directly opposed to the view of Helly. 1 that all transfused foreign erythrocytes reach the spleen pulp after traversing the venous sinuses, and are quite in accord with the observations of Gray 2 Mall 3 and Weidenreich, 4 who have ascribed the conspicuous injection of the marginal zone of the Malpighian corpuscles to the termination of abundant arterial capillaries in the intercullular spaces of the splenic pulp in this region.