Lectin staining of renal tubules in normal kidney

Lectins are glycoproteins able to bind carbohydrate structures specifically. In this study we applied six different lectins on normal renal tissue to investigate their specificity for different segments of the renal tubular system. The following lectins were used: jacalin, peanut agglutinin (PNA), wheat germ agglutinin (WGA), phytohemagglutinin E (PHA-E), concanavalin A (Con A), and Dolichos biflorus agglutinin (DBA). Particular attention was paid to jacalin lectin as its staining properties respecting the renal tubular system were not known. We showed that jacalin lectin strongly stains the luminal border of distal tubules, as well as single cells of the collecting tubules. As regards the other five lectins, PNA stained distal tubules, WGA the whole nephron, PHA-E proximal tubules, and Con A and DBA a few cells of the loop of Henle.

Quantitative PAS assay of some carbohydrate compounds and detergents

A spectrophotometric method for determination of color development of glycocompounds subjected to PAS reaction was investigated with various carbohydrate compounds and related chemicals. The conditions of the oxidation with periodic acid was found to influence the amount of the colored Schiff dye produced. Mono- and di-saccharides (mannose, glucose and maltose) were PAS-negative. Glycogen was more reactive than dextran. When glycogen was hydrolyzed by amylase the intensity of the PAS product dropped until a certain limit probably reflecting the limit dextrin. The presence of proteins (albumin) or electrolytes (NaCl) did not influence the PAS reaction. Many non-ionic detergents commonly used in membrane biology such as alkyl glycosides and gluco-methyl alkanamides were strongly PAS-positive and so was the anionic detergent SDS while the zwitterionic detergents tested, such as CHAPS and CHAPSO, were PAS-negative. The color development of the spectrophotometric PAS reaction showed linearity with the concentration of a simple glycoprotein solution (peroxidase) and a complex solution (bovine serum). By the PAS reaction it was also possible to measure the content of soluble and membrane bound carbohydrate compounds in a pellet of liver cell membranes. We find that the PAS reaction is sensitive and reliable for quantitative estimations of complex carbohydrates as well as soluble and membrane-bound carbohydrate compounds. The latter should be treated with PAS-unreactive zwitterionic detergents.