Study Of Lacidipine On Plaque Stability And The Expression Of CD36 MRNA In Carotid Atherosclerotic Rabbits.

Objective:To investigate the effect of lacidipine (Laci) on plaque stability and the expression of CD36 mRNA on commen carotid artery of hypercholesterolemic rabbits following balloon-injured.Methods:Thirty healthy balloon-injuried male New Zealand rabbits were exposed either to normal chow or high-cholesterol diet(HCD,contains 2% cholesterol,5% lard,0.5% sodium taurocholate and 92.5% normal animal feeds), and were randomized into five groups in each. normal chow group (control),high-cholesterol diet group (model), HCD plus low or high lacidipine(1mg/kg/d, L-Laci or 3 mg/kg/d, H-Laci),HCD plus atorvastatin(2.5mg/kg/d,Atorv) group. At the end of the sixth week,the body weight and femoral blood pressure were measured.Serum total cholesterol(TC),triglyceride(TG), low density lipoprotein cholesterol(LDL-C),total antioxidant capacity(T-AOC),superoxide dismutase (SOD), malonaldehyde(MDA) and oxidized low density lipoprotein-cholesterol (ox-LDL) were mesured.Then all rabbits were killed to perform the pathologic examinations.C reactive protein(CRP), matrix metalloproteinase-2(MMP-2) expression was analyzed by immunohistochemitry.The expression of CD36mRNA in common carotid artery were evaluated by semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR).Results: (1)The typical caroid atherosclerostic plaques were observed in all HCD groups.Compare with model,H-Laci and Atorv significantly reversed the progression of caroid plaques.(2)Comparing to model,H-Laci can step down systolic blood pressure(p=0.056). (3) The level of serum TC,TG and LDL-C increased significantly in model group(p＜0.01).Lipid profile was no difference between model and L-Laci or H-Laci group(p＞0.05).Compared with model,serum lipids were decreased significantly by atovastatin (p＜0.01).(3) Compared with control, serum SOD was decreased and MDA,ox-LDL was elevated in model(p＜0.01).Compare with model,H-Laci significantly increased serum T-AOC(p＜0.05),both H-Laci and Atorv decreased MDA,ox-LDL markedly(p＜0.01).L-Laci only descented ox-LDL obviously(p＜0.01).(4) In all high-cholesterol diet groups, CRP and MMP-2 expressions were high in the carotid plaques(p＜0.01).Comparing to model, L-Laci did not down regulated the expressions of CRP and MMP-2 in carotid plaques (p＞0.05),H-Laci and Atorv significantly down regulated the expressions of CRP and MMP-2(p＜0.01),but CRP expression was lower in Atorv group (p＜0.05). (5) Compare with control,CD36mRNA expression was obviously increased in carotid plaques in model(P＜0.01). H-Laci and Atorv markedly down regulated the expression of CD36mRNA in carotid plaques(p＜0.01,p＜0.05).The expression of CD36mRNA was higher in Atorv group than in H-Laci group(P＜0.01), but there was no diference between Atorv group and L-Laci group(P＞0.05).Conclusion: Both H-Laci and Atorv can delay the progression of common carotid plaque in experimental atherosclerotic model.It's antiatherosclerotic mechanisms may be that,H-Laci and Atorv have functions of antioxidation,anti-inflammation,decreasing the expressions of CRP and MMP-2 in plaque,down regulating the expression of CD36mRNA in atherosclerosis.