[Lectin reactivity in the kidney of newborn rat compared to adult rat].

The distribution of binding sites for 13 lectins with different specificities was studied in adult and new-born rat kidney tissue by staining paraffin sections with the ABC method. Various segments of the uriniferous tubule in both rats showed differential affinity for lectins. None of these lectins showed any reactivity with the immature developmental components of kidney like S-shaped bodies and mesonephric blastema. In the new-born rat kidney, the reactivity of 4 lectins (DBA, PNA, SBA and WGA) on the proximal tubules was very weak compared with the adult rat. Seven lectins (RCA-I, BSL-I, WGA, UEA-I, PHA-E, PSA, LCA), which stained the glomerulus of adult rats, failed to react with glomerular turf in new-born rat kidneys. On the contrary, 4 lectins (RCA-I, WGA, UEA-I and PHA-E) out of these 7 lectins stained the surface of podocyte in the new-born kidney. Colloidal iron stained glomerular turf in adult rats also showed less reactivity in immature glomerulus. These results suggested that changes in lectin binding reactivity are associated with the development and the differentiation of the rat kidney.