【Abstract】 Objective To explore the role of heparanase in the pathogenesis of respiratory syncytial virus (RSV) nephropathy in rats model. Methods Twenty 150-200 g Sprague-Dawley (SD) rats (n=5 per group) were inoculated with 6×10 6 PFU RSV and sacrificed on days 4,8,14 and 28 postinoculation (RSV 4,RSV8,RSV14 and RSV28). Five SD rats inoculated with Dulbecco’s minimum essential medium were served as normal control. The expression levels of heparanase protein and mRNA in the rat renal tissue of each group were determined by immunohistochemical staining and real-time quantitative RT-PCR respectively. The proteinurina was also measured and then the relationship between the expression level of heparanase and the 24-hour urinary protein was studied. Results The rats with RSV nephropathy exhibited higher proteinuria in comparison with normal rats, and the 24-hour urinary protein level was significantly different between each RSV nephropathy group (RSV14＞RSV8＞RSV28＞RSV 4, P 8and RSV14group were higher than those in RSV 4 and RSV28group （P r=0.783,P 4, RSV8, RSV14 and RSV28 group were elevated （RSV14＞RSV8＞RSV 428, Pr=0.725,P
