血脂异常诱导左心室不良重塑的实验研究及其与心肌微循环损伤的关联性OA

Objective To explore the impact of dyslipidemia on left ventricular(LV)structure and its association with myocardial microcirculatory injury.Methods Twenty New Zealand white rabbits were randomly divided into the dyslipidemia group and the normal control group.After 8 weeks of feeding,the isolated myocardial tissues of all experimental rabbits were obtained.The LV myocardial structure assessment indicators(including myocardial mass,heart cavity diameter and ventricular wall thickness)and pathological indicators(myocardial microvascular density and collagen volume fraction[CVF])were measured.Additionally,the biochemical indicators such as nitric oxide(NO),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and malondialdehyde(MDA)in the myocardial tissues of the experimental rabbits were evaluated by measuring the oxidative stress markers in the myocardial tissues.Results For the LV structural indicators,the myocardial mass and interventricular septal thickness in the dyslipidemia group were significantly increased compared with the normal control group(P＜0.001 for both).For the histopathological indicators,the myocardial microvascular density in the dyslipidemia group was significantly decreased,while the CVF was significantly increased(P＜0.001 for both).For the biochemical indicators,the levels of NO,SOD,and GSH-Px in the dyslipidemia group were significantly decreased,while the MDA level was significantly increased(P＜0.001 for all).The interventricular septal thickness was positively correlated with the CVF and MDA level in myocardial tissue,and negatively correlated with the myocardial microvascular density,NO,SOD,and GSH-Px levels(P＜0.001 for all).Compared with the normal control group,the myocardial tissue in the dyslipidemia group showed obvious fatty degeneration and inflammatory cell infiltration,as well as myocardial fibrous tissue hyperplasia and disordered arrangement.Conclusions Dyslipidemia can lead to adverse LV remodeling in New Zealand white rabbits and is closely related to myocardial microcirculatory injury.This suggests that early prevention and control of dyslipidemia may help improve the poor prognosis of cardiovascular events.