Effects of concanavalin A on intestinal brush border enzyme activity in broiler chickens.

1. The effects of Concanavalin A (Con A) on enzymes from the intestinal brush border were studied using membrane vesicles (BBMV) prepared from 3- and 6-week-old broiler chickens. 2. Maltase, sucrase, phytase, alkaline phosphatase and leucine aminopeptidase activities were assayed in BBMV in the absence (T0) or presence (T1) of Con A, or in the presence of casein (T2). Disaccharidase specific activities were assayed in the presence of Con A that had been pre-incubated with the enzyme (T3) or with the substrate (T4). 3. Con A significantly affected maltase and sucrase activities in 3-week-old broiler chicken intestinal BBMV. Pre-incubation of the lectin with the maltase or its substrate had no effect on enzyme activity. Pre-incubation of Con A with sucrose reduced enzyme activity. 4. Con A did not affect phytase, alkaline phosphatase or leucine aminopeptidase activities. 5. Maltase, alkaline phosphatase and leucine aminopeptidase activities were lower in 6-week-old than in 3-week-old broilers.