The cellular specificity of lectin binding in the kidney. I. A light microscopical study in the rat.

In order to estimate the usefulness of lectins in the study of the functional segmentation of the nephron, the sites of binding of five lectins were identified in the rat kidney. Lectin-peroxidase conjugates were applied to cryostat sections. The bound conjugates were stained with 3,3'-diaminobenzidine for light microscopical observation. Each lectin has a specific binding pattern along the nephron. Reversely, the different segments of the nephron defined by other histological methods can be identified on the basis of their affinity for lectins. The different parts of the thick ascending limb, namely the medullary segment, the cortical segment and the macula densa, can be distinguished even more readily with lectin histochemistry than with any other histochemical procedure. The binding of lectins to luminal membranes in some segments indicate the possibility to use lectins for the separation of particular cell types and for the modification of the transport properties of their membranes.