Abstract：Objective: The preventive effects of Saikosaponin-d (Ssd ) on the progression of mesangioproliferation and glomerulosclorosis, induced by intravenous injection of anti-Thy1 monoclonal antibody (mAb) 1-22-3 into uninephrectomized rats, were evaluated. Methods: Eighteen rats were divided into three groups of six. One group was treated with phosphate buffered saline (PBS) as a control. The other two groups were treated with Ssd 1.8 mg/kg body weight (BW)./day or 0.6mg/kg BW/day respectively. Urine samples were collected from the rats in metabolic cages on days 1, 4, 8, 14 and 21 after the injection of mAb 1-22-3. Systolic BP(SBP) was tested on days 1, 5, 10, 14 and 18 after the injection. All rats were sacrificed 21 days after the injection of mAb 1-22-3 for blood biochemistry, and immunofluorescent and light microscopy of the kidneys. Results: Ssd suppressed proteinuria, extracellular matrix expansion, crescentic formation as well as inflammatory cell infiltration. Especially, Ssd was sh...更多own to have highly significant suppressive effect on CD8+T cells infiltration into the periglomerular and tubulointerstitial areas and on expression of TGF-a type I collagen in the kidneys and α-SMA along Bowman's capsule. Conclusions: Our study indicates that Ssd could prevent initiation and progression of mesangioproliferative glomerulonephritis in rats through inhibition of CD8+ T cell infiltration, macrophage accumulation and activation, and expression of TGF- and type I collagen in the kidneys.