Study On The Relationships Between Lipoprotein-Associated Phospholipasea2 And High Sensitivity C-Reactive Protein With Atherosclerosis Plaque Stableness

ObjectiveThe research makes an attempt to build an animal model of Unstable Atherosclerotic plaques in artery, evaluate the value of Lp-PLA2 and hs-CRP in the serum, conbaining with IVUS indice ,and probe into its Prognostic Value of Lp-PLA2 and hs-CRP Level in the Serum in Unstable Atherosclerotic Plaques.The unstablebility of AS plaque in other words the erosions, ulcers, raputure and thrombosis of plaque is the basic pathology cause of acue heart clinical incidents, simple, convenient and effective prediction the stablility of AS plaque makes deep sense in early prevention acut cardiovescular accidents. Lipoprotein-associated phospholipase A₂ is found as an inflammatory symbol close related to coronary artery pathological changes, and is proved to be a danger factor to CHD with High sensitive C-reactive protein, but the relative research forecasting on the stability of AS plaque is less . IVUS is the golden standered in eveluation of vasculer changes, but it is difficltly developed in clinical use for its high cost.So we try to enplore the relationship between Lp-PLA2 , hs-CRP and the plaque stability in artery ,and look for a simple and effective way to forecast the stabaleness of AS plaque.Methods1, Forty eight New Zealand White rabbits were randomly divided into 4 groups with 12 rabbits each, including control group, stable plaque group, P53 group, and P53+drug group.2, Rabbits in control group were fed on a regular diet. Rabbits in stable plaque group, P53 group and P53+drug group underwent balloon induced arterial wall injury andthen were fed on a diet of 1% cholesterol; They were all fed for 12 weeks.3,Then the rabbits in P53 group and the P53+drug group underwent Ad5-P53transfection by hypodesmus from arteria iliaca communis to right rennl artery in theend of 10th week;4,The P53+drug group underwent pharmacological triggering with Chinese Russell'sviper venom (CRW) and histamine in 24 hours and 48 hours before killed. IVUSwas used before sacrifice of animal and calculated the external elasticmembrane area,lumen area, plaque area , lumen area narrowing rate, lumen eccentricity index andremodeling index.5,In the 0th week and 12th week, the four rabbits underwent blood collectionform medium-sized artery of ears, run the determination of the Lp-PLA₂ and hs-CRPlevel in serum by enzyme linked immunosorbent assay of double antibody sandwich.6,After the sacrifice of animal, dying HE, ISH.Results1. in the process of experiment, two rabbits in stable plaque group died in anesthesia accidents, three rabbits were eliminated because of failing to meet model standerd . forty-three rabbits finished the experiment, including twelve in normal control group, ten in stable plaque group, ten in P53 group and eleven in P53+drug group.2,The serum Lp-PLA₂ levels in P53 group and P53+drug group were significantly higher than those in the stable group (P <0.05) ; the serum Lp-PLA₂, hs-CRP level in P53+drug group makes significant difference in P53 group and P53+drug group (P <0.05) ; The serum hs-CRP level makes little difference in stable group and control group (P>0.05) , but Lp-PLA2 level is significant (P<0.05) .3,In the IVUS results, the values of fibrous cap thickness, plaque area, lumens area stricture, Dmax, Dmin in stable group, P53 group and P53+drug group were significantly higher than those in normal control group (P <0.05); In the P53 group and P53+drug group the values of fibrous cap thickness were significant lower than that in the stable group (P <0.05), in the P53 +drug group the raputure and thrombsis were significant higher than that in P53 group (P <0.05) RI and EI in P53 group and P53+drug group were significantly higher than those in stable group (P <0.05)4,There is inverse correlation between the serum Lp-PLA2 level and the fibrous cap thickness (r=-0.710, P <0.01) , positive correlations to EI and RI (r=0.860, P <0.01, r= 0.810, P <0.01) . Serum hs-CRP level is nagtive relative with plaque burden and index of remodeling (P >0. 05) .5,The results of HE dyeing displayed: Rabbits in plaque group had plaques with the circellus-artery wall homogeneous distribution. The tunica intima of artery wall became thicher and the plaque had formation of foam cells, thinner tunica media. ESCA,MLA, PA were significant differernce than that in control group (P <0.05) . The disruption by chance in rabbits of P53 group increase significantly (P <0.05) . The disruption and thrombosis by chance in endomenbrane in rabbits of P53+drug group increase significantly (P<0.05) .6,Tissue Lp-PLA2 expression in stable group, P53 group and P53+drug group increase significantly (P <0.05) . Tissue Lp-PLA2 and hs-CRP expression in P53+drug group make significant difference than that in P53 group (P <0.05). Tissue Lp-PLA2 makes difference between control group and stable group (P >0.05), while hs-CRP makes no difference (P<0.05) .Conclusion1,On the base of animal successful AS model , rabbit serum Lp-PLA2 revealedsignificant relationships with IVUS results including fabric thicker, RI and EI. It canbe considered to predict plaque instability.2,An comparison of Rabbit serum hs-CRP and IVUS results revealed nagnitiverelationship. But it can be used as a reference index to predict plaque instability for thesuperior sensitivity. .3,Serum Lp-PLA2 level has higher sensitivity in predicting the vulnerability ofthe plaque, combined with hs-CRP, we may considered the two as new biomarkers topredict animal vulnerable plaque.