Microscopic and lectin histochemical studies were performed using the cerebella of 33 natural cases of Solanum fastigiatum var. fastigiatum intoxication in the cattle from southern Brazil and 2 natural and 4 experimental cases of Solanum bonariense from Uruguay. The following biotinylated lectins were used in both cases: WGA, sWGA, BS-I, Con-A, RCA-I, DBA, and UEA-I, with the addition of LCA in S. fastigiatum poisoning cases. Histologically, the lesions consisted of fine vacuolization, distention of portions of the Purkinje cells, axonal spheroids measuring 14-50 m in the granular cell layer and adjacent white matter and, proliferation of the Bergmann?s glia. Lectin histochemistry revealed strong reactivity of stored material in Purkinje neurons with the lectins sWGA, Con-A, and LCA in S. fastigiatum cases. A similar pattern was found in S. bonariense cases with a most intense reactions to WGA, and less intense reaction to Con-A, whereas BS-I and RCA-I binding was absent to poor in these neurons in all the cases studied.Lectin reactivity in Purkinje cells between cases was independent of cell damage (from mild to severe loss of neurons). Both S. fastigiatum and S. bonariense have similar lectin binding, suggesting a similar pathogenesis. Since comparable binding patterns have been described in animals poisoned with swainsonine-containing plants, perhaps the toxins in these plants contain related glycosidaseinhibiting toxins or inhibit glycoprotein and lysosomal metabolism through some related mechanism. The results of this study showed that in spontaneous poisoning by S. fastigiatum and S. bonariense in the cattle, the pattern of lectin binding is similar to those observed in S. fastigiatum experimental conditions.Fil: Sant’Ana, Fabiano J.F.. Universidade Federal de Santa Catarina; BrasilFil: Barbeito, Claudio Gustavo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Nishida, Fabian. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Gimeno, Eduardo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Verdes, José M.. Universidad de la República. Facultad de Ciencias; UruguayFil: Moraña, Antonio. Universidad de la República; UruguayFil: Barros, Claudio S.L.. Universidad de la República; Urugua
