Objective   To study the extraintestinal lesions induced by rotavirus (RV) infection and explore the pathogenesis.   Methods   Simian rotavirus SA11 was cultured in MA-104 cells. After inoculation

the pathological changes in brain

lung

heart

liver

pancreas and kidney tissues were observed

the RV antigens detected

and the apoptotic cells observed. Besides

we stained the filamentous actin (F-actin) with Phalloidine-TRITC

and then quantified the F-actin amount.   Results   Several pathological changes

inclusive of myocardial interstitial edema

granular degeneration in cardiacytes

hepatic congestion

and hepatocellular vacuolar degeneration

were found

but not found in the brain

lung

and pancreas tissues. Meanwhile

several ultrastructural changes

inclusive of dissolved myocardial F-actin

extended smooth endoplasmic reticulum

swollen mitochondria

and widened perinuclear space

were found. No difference was found in the quantity of myocardial F-actin. Apoptosis was found in liver cells

but not in myocardial cells. RV RNA was detected in tissues such as brain

lung

heart

liver and pancreas tissues.   Conclusion   All the results suggest that RV may spread from the intestine to various extraintestinal organs and hence induce injury. Filamentous actin depolymerization

cytoskeleton damage and apoptosis induced by RV infection are the important mechanism not only in intestinal damages

but also in extraintestinal lesions.