Renal effects induced by the lectin from Vatairea macrocarpa seeds

Lectins are glycoproteins that interact reversibly and specifically with carbohydrates. The renal effects of the galactose-binding lectin from the seeds of Vatairea macrocarpa were investigated. Isolated kidneys from Wistar rats (240-280 g) were perfused with Krebs-Henseleit solution containing 6% bovine serum albumin. The V. macrocarpa lectin (10 microg mL(-1)) increased the perfusion pressure, renal vascular resistance, urinary flow and glomerular filtration rate. However, V. macrocarpa lectin did not change the percentage sodium, potassium or chloride tubular transport. Pre-treatment with lectin-galactose complex significantly blocked the increase in perfusion pressure, renal vascular resistance, urinary flow and glomerular filtration rate. The control group showed a small amount of a proteinaceous material in the urinary space, although no alteration in the renal tubules was detected. The administration of galactose alone did not modify the functional parameters of the kidney. Kidneys perfused with V. macrocarpa lectin showed moderate deposits of a proteinaceous material in the tubules and urinary space. Those pre-treated with lectin-galactose complex had only small amount of a proteinaceous material in the urinary space. No abnormalities were seen in renal tubules. The results suggest that lectin from V. macrocarpa seeds has important effects on the carbohydrate-binding sites of the renal system, given the reversal of renal effects with the use of that specific inhibitor.