Department of Tropical and Occupational Health, High Institute of Public Health, Alexandria University, Department of Biology, College of Science, and Department of Pathobiology, College of Veterinary Medicine, Texas A & M University, Alexandria, Egypt
The influence of various dietary zinc levels on the fibrotic aspects of granuloma formation and on the humoral response to schistosome egg antigens was investigated in CB57B1/6 mice by feeding groups of animals zinc-deficient diets. At six weeks of age, control and zinc-deficient mice were exposed individually to 50–60 cercariae of the Brazilian LE strain of Schistosoma mansoni. The animals were maintained on their respective diets for eight weeks postinfection, then all animals were killed and analyzed for body weight, spleen weight, collagen content of the liver, in vivo granulomatous histopathology, and antibody responses to soluble egg antigens. Zinc-deficient mice experienced stunted growth and reduced weight gain. Granulomatous hypersensitivity to schistosome eggs in the liver was measured in liver histopathologic sections using morphometric analysis and was found to be depressed in infected mice fed the moderately and the severely zinc-deficient diets. The low level of zinc in the diet also affected the humoral immune response of the host to schistosome egg antigens.