Relationship between macrophage infiltration in the coronary plaque and downstream myocardial perfusion in mice / 中华超声影像学杂志

ABSTRACT

Objective:To explore the relationship between macrophage infiltration in the coronary plaque and downstream myocardial perfusion in mice.Methods:The experimental group consisted of 20 ApoE knockout mice models of the coronary plaque established by feeding with cholesterol-rich diets, and the control group consisted of 20 sex- and age-matched C57BL/6 mice with the same genetic background as ApoE mice.Adenosine stress myocardial contrast echocardiography was performed on all experimental animals to obtain the values of A, β and A×β of the left ventricular myocardium in anteroseptal and posterior walls both in the resting status and during adenosine stress. Concentrations of serum interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were determined using mouse enzyme-linked immunosorbent assay kits according to the manufacturer′s instructions. The degree of macrophage infiltration in the coronary plaque was evaluated by pathological immunohistochemistry staining and the correlations with the above indicators were analyzed.Results:There were no statistically significant differences in heart rate and left ventricular structural parameters between two groups (all P>0.05). The experimental group had a lower left ventricular ejection fraction( P=0.021), and higher weight and serum levels of triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, IL-6, and TNF-α than the control group (all P<0.05). The values of A, β and A × β of the left ventricular myocardium in anteroseptal and posterior walls in the experimental group were significantly lower than those in the control group during adenosine stress (all P<0.05). In the experimental group, the value of the macrophage infiltration found in the plaque of the left main coronary artery correlated positively with the level of serum TNF-α ( r=0.63, P=0.003) and negatively correlated with the values of A×β of the left ventricular myocardium in anteroseptal and posterior walls during adenosine stress ( r=-0.74, P<0.001; r=-0.72, P<0.001; respectively). Conclusions:Myocardial perfusion in ApoE knockout mice models of the coronary atherosclerosis was related with degree of macrophage infiltration in the coronary plaque, and macrophages may play a role by releasing inflammatory mediator TNF-α.