Experimental Research On The Effects Of Ginkgo Leaf Extract And Diphyridamole Injection In Tubulointerstitial Fibrosis Of Rats With Unilateral Ureteral Obstruction

Objective: To observe the expression of transforming growth factor-betal intubulointerstitial fibrosis of rats with unilateral ureteral obstruction.To research the effectsof drugs Ginkgo leaf extract and diphyridamole injection and mechanism ontubulointerstitial fibrosis.Methods: 45 normal male Sprague-Dawley rats with 6-8 weeks old were randomlydivided into sham-operated controls, n=15 the animals were anesthetized with chloralhydrate 30rag per 1kg body, and the left ureter was exposed via an abdominal incision.The ureter was not dissected and liberation. The abdomen was closed with silk suture, Theunilateral ureteral obstruction group i.e. models, n=15: the operation was made in a similarmanner with the ureter was dissected and liberation. Medicine- interventing group, n=15:Ginkgo leaf extract and diphyridamole injection 12.5ml per 1kg was inject into rats'abdominal cavity a time every a day on the 2nd after operation. Six rats of each groupwere sacrificed by neck fracture under chloral hydrate anaesthesia respectively on the2nd,3rd and 4th weeks after surgery. Before they were killed, 24 hours urinary volume ofrats were collected by metabolic cage and 24 hours quantitation of urine protions weredetected just before sacrificing. One ml of blood was harvested from heart and blood ureaand creatinine were detected by automatic biochemistrical analysator. The whole structurewas observe by naked eye and renal interstitial fibrosis was examined by routinehematoxylin and eosin (HE) Masson staining. Semiquantitative analysis of renal interstitialfibrosis were completed by Motic Med 6.0 multimedia medical analytical system of colorgraph and writing.Ultramicrostructure of renal interstitial was observed by electronmicroscope. The expression of TGF-β₁ in every group were detected byimmunohistochemistry.Results: In comparison with sham-operated controls, rats' left kidney in the unilateral ureteral obstruction(UUO) group were markly enlarged, pale, renal parenchymal thinning,the bouncary between renal cortical and medulla was indefinite, dilatation of collectingsystem. These changes were severier when time of unilateral ureteral obstruction waslonger. HE staining displayed more infl-cells infiltrate in interstitial, diffusal vacuolardegeneration in renal tubule after unilateral ureteral obstruction. Part of renal tubule focaldistend,atrophy and necrosis, interstitial gently fibrosis. These changes got graduallysevery on 3rd and 4th weeks after operation. But these changes lessened in rats of Ginkgoleaf extract and diphyridamole interwenting group.interstitial infiltration and fibrosis can be seen resectively 2nd and 4th after operation.Masson staining displayed interstitial infiltration and areas of stained yellow were more inrats of the unilateral ureteral obstruction group than rats of sham-operated controls. Andinterstitial infiltration and areas of stained yellow in rats of Ginkgo leaf extract anddiphyridamole interventing group were less than rats UUO group. Basal membrane ofnephric tubule thicking, many chondriosomes swelling in cellula epithelialis of renal tubule,inflammatory cell infiltrating and forming of fibrosis in tubulointerstitiam can be seen byelectron microscope in the UUO group. However, these changes were gentler Ginkgo leafextract and diphyridamole interventing group than they in the UUO group.Immunohistochemistry analysis displayed that the levels of TGF-β₁ paralleled thehistological changes of tubulointerstitial fibrosis and didn't correlated to the scores oftubulointerstitial damage (β=-0.197, P=0.639). But the levels of TGF-β₁ remarkablycorrelated to the areas of tubulointerstitial color stain(β=0.935, P=0.000). 24 hoursquantitations of urine protions of rats were not remarkably different in each groups. Incomparison with control groups, level of blood urea and creatinine of rats weresignificantly higher on the 2nd week in the UUO groups. On the 3rd week the level of themdecreased and kept on decreasing on the 4th week. On the 2nd week level of blood ureaand creatinine of rats slowly increased in the Ginkgo leaf extract and diphyridamoleinterventing groups.And on the 3rd and 4th week the level of them remarkably decreased.Conclusions: Unilateral ureteral obstruction of rats is animal models of renal interstistitialfibrosis. TGF-β₁ is a important factor in renal interstistitial fibrosis and its level representthe degree of interstistitial fibrosis. Ginkgo leaf extract and diphyridamole significantlydelays progress of renal interstistitial fibrosis and inhibits the expression of TGF-β₁ is one of mechanisms.