Abstract   

Comparative histochemical studies on the spleen damage following infections with Schistosoina mansoni and Schistosoma margrebowiei have been reported after 42, 49, 77, 91, 105 and 119 days post-infection (p.i.) in definitive host mouse. The most prominent changes were the protein stained positively in capsule and trabeculae with mild amounts observed in red and white puips of the spleen of mouse. Glycogen was stained weakly in capsule and white pulp, however, an increased amount was observed in red pulp of the spleen from 42 to 119 days p. i.. S. mansoni and S. inargrebowiei egg embryos were stained markedly for glycogen from 91 to 119 days p.i.. Acid mucopolysaccharide was stained weakly in the spleen of mouse. Increased amount of ribonucleic acid was observed in nuclei of connective tissue, endothelial cells and megakaryocytes present in the spleen. Mast cells around the granulomas and fibrosis were stained positively for protein, glycogen, acid mucopolysaccharide, ribonucleic acid, weakly for ferric irons and negatively for lipofuscin pigments from 91 to 119 days p.i.. Ferric iron was absent from normal capsule and white pulp, but small amounts were present in trabeculae and red pulp of the spleen in both parasite infections. The endothelial cells in the blood vessels walls were stained positively for lipofuscin pigments in normal and after all parasite infections.