2000 Volume 41 Issue 3 Pages 188-193
Subchronic animal feeding studies to examine the effect of glyphosate-tolerant soybeans, which contain the bacterial 5-enolpyruvylshikimate-3-phosphate synthase from Agrobacterium sp. strain CP4, on the immune system were conducted with BN rats and B10A mice. The studies were designed to compare the feeding value of a line of genetically modified glyphosate-tolerant soybeans (GM soybeans) to that of closely-related and one-parent same cultivar (non-GM soybeans). Heat-treated soybean meal was incorporated into the diets of the rats and mice at a concentration of 30%. The study duration was 15 weeks. Growth, food intake and weights of the liver and the spleen were compared between animals fed the non-GM and GM lines. The histopathology of the thymus, liver, spleen, mesenteric lymph node, Peyer's patches, and small intestine, and the production of soybean-specific IgE and IgG antibodies in the sera were also compared. Growth, feeding value, and the histopathology of immune-related organs showed no significant differences between animals fed GM and non-GM lines. The production of soybean-specific IgE was not detected in the sera of either group, and the increase in soybean-specific IgG was identical in the GM and non-GM groups. No immunotoxic activity was found in GM-soybean-fed rats or mice.