OBJECTIVETo investigate the effect of testosterone on neointimal proliferation and blood lipids after balloon-induced aorta injury in male rabbits.

METHODSTwenty-five male white rabbits were randomly divided into five groups with 5 in each. G1 underwent sham castration served as control group, rabbits in remaining 4 groups were castrated. One week after the castration, rabbits in G3, G4, G5 groups received 3 mg/kg, 6 mg/kg, 12 mg/kg testosterone undecanoate i.m, respectively, G2 was not received. Two weeks after the castration, deendothelializing balloon-induced injury in right iliac artery was performed in all animals. Two weeks after the injury, blood samples were drawn for measurement of plasma testosterone and lipids, and the right iliac arteries were excised for computer imagining analysis.

RESULTCompared with G1, plasma levels of total cholesterol(TC), triglycerides(TG), low density lipoprotein(LDL) in G3, G4 and G5, gradually decreased, plasma levels of high density lipoprotein(HDL)gradually increased. There were most significant differences of plasma TC, TG and LDL(P<0.05) between G2 and G1. There were not significant differences of plasma TC, TG, HDL and LDL among all groups before endothelial denudation and 2 weeks after endothelial denudation (P>0.05). In G3, G4 and G5 the intimal area and radio of intima/media gradually decreased, there were significant differences between G2, G3, G4 and G1(P<0.05), the differences between G1 and G2 were most significant, and those of G5 were close to G1. Endothelial cell repair was observed with electron microscope. Endothelial cells from G2 to G5 became smoother gradually, which in G5 were very close to G1.

CONCLUSIONTestosterone inhibits the intima proliferation induced by balloon-induced injury and improves blood lipids levels. The effects are enhanced by the dose increasing.