Effects Of Tetracycline On Atherosclerotic Plaques Of Model Rabbits

Objective: To observe the effects of tetracycline on expression and activity of matrix metalloproteinase-2 in atherosclerotic arterial tissues of rabbits, on development of vascular remodeling in atheroscerosis and stabilization of atherosclerotic plaque.Methods: 30 male New Zealand rabbits were randomly divided into 3 groups:control group, model group, tetracycline group. The rabbits were fed on a normal diet(n=10) or a cholesterol diet (cholesterol 1. 0 g/d;lard 5.0 g/d, n=10)or a cholesterol diet with tetracycline (cholesterol 1.0 g/d;lard 10 g/d; tetracycline 0.25 g/d per rabbit ,n=10) for 12 weeks, the descending aortas were harvested for immuocytochemical staining, HE staining, Masson' s staining, respectively.The activity of MMP-2 was measured by zemography, the results were analysed by image analysis soft.Results : Compared with control group, the intimal thickness increased significantly in cholesterol diet groups (P<0. 01). The intimal thicknes/ the media thicknes was decreased in tetracycline group comparing with that of model group(P<0. 05) , the thickness or area of plaque fibrocap/ the thickness or area of fat pool was increased in tetracycline group comparing with that of model group(P<0.01). The activity and expression of MMP-2 in cholesterol diet groups increased significantly comparing with that of control group(P<0. 01) ;Compared with that of model group, the activity and expression of MMP-2 in tetracycline group decreased accordingly(P<0. 01).Conclusion: The atherosclerotic model of rabbits were copied successfully, The expression and activity of MMP-2 in atherosclerotic plaque increased significantly, Treatment with tetracycline decreased the expression and activity of MMP-2 , increased the thickness of plaque fibrocap and inhibited development of atherosclerotic plaque .