Effects Of Astragalus On The Expressions Of STAT-1 And ICAM-1 Kindey In Rat After Ischemia/Reperfusion Injury

Objective: To investigate the possible effect of astragalus on the expressions of STAT-1 andICAM-1 in rats with renal ischemic-reperfusion injury（IRI）, in order to explore its effects in ratswith renal IRI.Methords: Fouty-eight healthy male wistar rats were randomly divided into four groups:sham groups，model groups, Losartan and Astragalus treatment group（n=12）. Within each group,rats were randomly divided into two subgroups: IR6h and IR24h groups （each subgroup n=6）.The renal models of acute ischemia-reperfusion were made in rats by placing the vascular clampin bilateral renal pedicle to block the blood circulation for 45 minutes. In sham group, renalarteries were founded but not clipped for 45 minutes. The two treatment groups were treated byinjecting into stomach with Losartan potassium (80mg kg^-1 d^-1and Astragalus （0.7g/ml） for 7days before ischemia respectively. The sham and model groups were received the same volumeof the distilled water for 7 days before surgery. The level of blood serum creatinine（Scr） wasmeasured 6h and 24h after reperfusion, then the rats were euthanized in batch. Histopathologicaldamages were monitored accordingly. The expressions of STAT-1 and ICAM-1 in renal tissuewere measured by immunohisto-chemical stain.Results:1. In the sham group, the level of Scr 6h and 24h after reperfusion did not change clearly, Butamong the ischemia-reperfusion and two treatment groups, the level of Scr have increased 6hafter reperfusion, and to peak 24h later. In the two treatment groups, the level of Scr wasmarkedly higher than that of the sham group 6h and 24h after reperfusion respectively（bothP<0.01）, however lower than those of the model group （both P<0.01） at the same time points.The level of Scr between the Losartan and Astragalus treatment groups at the same time pointwas not significantly different（P>0.05）.2..In the sham groups, it is normal in the organizational structure of renal. In theischemia-reperfusion groups, the renal tubular epithelial cells displayed different degree swelling,necrosis, falling off and inflammatory cells infiltrating obviously in the renal interstitial. But inthe treatment groups, the renal pathological changes were significantly lighter than the modelgroup.3. The STAT-1 and ICAM-1 were not expressed in the sham groups, but expressed in the otherthree groups. The level of them have increased 6h after reperfusion, and to peak 24h later. Compared with the sham group at different time points, it was significantly different（P<0.01）. Inthe Losartan and Astragalus treatment groups, the expression of STAT-1 and ICAM-1 weremarkedly lower than model group at the same time point after reperfusion （ P<0.01）.The level ofSTAT-1 and ICAM-1 in Astragalus treatment groups was not significantly different compared tothe Losartan at the same time point（P＞0.05）.Conclusion:The pretreatment of astragalus can protect renal function against the renal ischemia-reperfusion injury. As the levels of blood serum creatinine decreased, the expression level ofSTAT-1 and ICAM-1 protein were markedly downregulated after the ischemia- reperfusioninjury. These results imply that astragalus whose mechanism may be involved in the inhibition ofSTAT-1 expression can protect renal against the acute renal ischemia/reperfusion injury.