| Abstract: | The antinutritional effect caused by the ingestion of lectins from two Brazilian varieties of beans: Rico 23 and Jalo, was studied in rats. The two varieties were selected in a previous screening of toxicity in rats: one of them (Jalo) was lethal, and the other (Rico 23) was not, when injected intra-peritoneally. Different amounts of each one of the lectins were added to casein experimental diets and fed to rats. The amount of protein (casein) also varied from 5% to 20%. The addition to the diet of 1% lectins from the Jalo variety caused a growth depression, as well as a decrease in food efficiency ratio and serum glucose; also, it reduced the maltase and invertase activity of the intestinal mucosa. All these effects appeared when the protein contents in the rations were 5% or 10%. At the 20% level only a depression of the maltase activity was observed. Similar effects were shown by the lectins of the Rico 23 variety, but only when added in a higher (5%) percentage to the diet. The phosphatase and protease activity were not changed by any of the lectins. The inhibitor activity that occurred in vivo was not detected in vitro. |
