Study of the Effectiveness of Amiloride on Angiostenosis after Balloon Injuries in Rabbits

Objective:To explore the effectiveness of the sodium-hydrogen exchanger(NHE)inhibitor(Amiloride)on angiostenosis after balloon injuries in rabbits.Methods:Thirty-two New Zealand white rabbits were randomly divided into intervention group(IG)with 12 rabbits,control group(CG)with 10 rabbits and pseudo-operation group(PG)with 10 rabbits.Amiloride[5?mg/(kg·d)]was injected intraperitoneally,3 times a day in IG and the same dosage NS was used in the same way in CG till 28 days after operation.Then the rabbits were killed and the iliac arteries were taken out and stained with Hematoxylin-eosin,α-actin and Masson's trichrom to observe the morphologic changes of the vessel cave,neointima and the media layer and the vascular smooth muscle cell migration into the neointima and the extracellular matrix(ECM)in the vessel walls.Results:Four weeks after balloon injuries in rabbits,the cave of the iliac artery was extremely narrow and neointima was formed and the media layer was proliferated.Compared among IG,CG and PG,the cave areas were(0.91±0.23)mm~2,(0.68±0.19)mm~2,(1.08±0.17)mm~2(F=7.631,P0.01)respectively.The intima areas of three groups were(0.27±02?5)mm~2,(0.67±0.24)mm~2,(0.05±0.03)mm~2(F=36.947,P0.01)respectively.The ratios of intima to media area were(1.21±0.24),(1.39±0.26),(0.15±0.08)(F=7.562,P0.01)respectively.After intervented by Amiloride,the vessel cave areas were enlarged and intima areas and the ratios of intima to media area were decreased.In IG compared with CG,the α-actin positive areas in neointima were decreased[(4?164.15±1?788.37μm~2 vs.(16?328.31±6?220.27)μm~2 with P0.01]and the ECM areas in neointima were smaller[(8?910.62±7?041.62)μm~2 vs.(333?558.76±7?290.17)μm~2 with P0.01].Conclusion:Amiloride can relieve the angiostenosis through increasing cave areas and decreasing neointima area and development of ECM.Maybe this kind of drug is useful in prevention of the (res-)tenosis after percutaneous transcoronary angioplasty.