The vascular supply of splenic autotransplants.

The close opposition of blood to phagocytic cells lining the pulp cords and marginal sinus has been proposed as a contributing factor in the clearance mechanism of the spleen. The vasculature of splenic autotransplants was investigated in rats using microcorrosion casts. Six-month-old splenic autotransplants and unoperated control spleens were selectively perfused and a methyl methacrylate cast was made. Scanning electron microscopy of these corroded casts was performed. In autotransplants, the marginal zone capillary network was abnormal with the fine network of capillaries replaced by dilated blood vessels. The red pulp cords were also found to be abnormal with increased diameter and loss of the fine saccular dilations found in normal spleens. The abnormally dilated capillaries and cords in the autotransplants may decrease antigen contact with these cells and hence explain previous reports of reduced phagocytic function.