RHEOLOGIC CHARACTERIZATION OF VEGETAL LECTINS BY DISSOCIATION OF INDUCED ERYTHROCYTE AGGLUTINATES

Energy evolved from hemagglutination reaction or spent in dissociating erythrocyte agglutinates has been proved to be an excellent parameter for analyzing cell-cell interactions mediated by bridging molecules s uch as antibodies or lectins. We developed a new rheo-optical method t o estimate the energy of dissociation of red blood cell agglutinates. In a Couette shear field agglutinates can be dissociated until a suspe nsion of monodispersed cells is obtained. Intensity of light backscatt ered by suspended agglutinates increases during their mechanical disso ciation. Variation of backscattered light intensity correlates with th e energy spent in the process. The adhesive energy of erythrocyte aggl utination induced by lectins has been estimated by applying this metho d. Two specific lectins (Dolichus Biflorus agglutinin and Ulex Europae us agglutinin) and a new lectin obtained from Amarantus Cruentus seeds which specificity is unknown were studied. Results obtained in this w ork for Dolichus Biflorus lectin are comparable with values published by other authors. An asymptotic decrease of adhesive energy was observ ed when the mechanical dissociation was applied several times on the s ame sample. Our results suggest that the cell detachment is accompanie d by the extraction of membrane receptors. This finding is consistent with results obtained by other authors.