Lectin-peroxidase conjugate reactivity in normal human kidney

The carbohydrate histochemistry of normal human kidney has been investigated by the use of four peroxidase-labeled lectins at the light and electron microscopic level. The results show that the lectin of Lotus tetragonolobus, specific for l-fucose, binds exclusively to the proximal convoluted tubules of the nephron. While peanut and soybean lectins, specific for D-galactose and N-acetyl-D-galactosamine, respectively, are confirmed to the collecting ducts, wheat germ lectin, specific for sialic acid and N-acetyl-D-glucosamine, stains several parenchymal structures, including the glomerular capillary wall, particularly its podocyte cell coat. Sialidase digestion reveals strong binding sites for peanut and soybean lectin in the glomeruli. At the ultrastructural level most of the binding is shown to be on the podocyte surface and within the lamina rara externa of the basement membrane. The technique represents a potentially very useful tool for the study of various pathological states in the kidney.