On pathogenesis of rotavirus diarrhea in suckling mouse / 第三军医大学学报

ABSTRACT

Objective To study the pathogenesis of rotavirus(RV) diarrhea.Methods Simian rotavirus(SA-11) was grown in cultured MA-104 cell.The viral titers of the culture supernatant were determined by plaque forming assay.KM mice aged 7 days were inoculated with the viral supernatant via feeding tube(gavage).Histological and ultramicrostructure changes of the small intestines were observed under light microscope and electron microscope.The values of crypt depth and villi height were measured with software(image pro plus 5.1,IPP5.1).The distribution of the RV antigen in small intestine and the filamentous actin of the small intestine chorioepithelium were observed with immunohistochemical techniques.The apoptosis of the small intestine epithelium cells was observed with an in situ apoptosis detection kit.Results There were mild hyperemia,dropsy and extensive vacuolar degeneration of small intestine villi under light microscope.Plenty of lipid droplet-like structure at the top of the villi,microvilli malalignment or defluxion and enterocyte defluxion could be seen by electron microscope,but no obvious structure changes at the cell junctions were seen.The RV antigen mainly distributed at the top of the villi.The quantity of small intestine filamentous actin decreased and enterocyte apoptosis increased after RV infection.Conclusion RV mainly infects the mature villous epithelium.The presentation of RV diarrhea relates to the lesion of cytoskeleton,the microvilli lesion of the small intestine,enterocyte apoptosis and defluxion,villi atrophy,etc.,but may have no relationship with the structural changes of cell junctions in the small intestine epithelium.