Evaluating The Effect Of Pioglitazone On Vulnerability And Calcification Of Atherosclerotic Plaque In Rabbits Using ¹⁸F-FDG PET/CT

Objective:To investigate the effect of pioglitazone on atherosclerotic calcification and plaque vulnerability in rabbits by 18F-FDG-PET-CT and the correlation between calcification and vulnerability.Research methods:Twenty male New Zealand white rabbits were randomly divided into two groups,pioglitazon group?n=10?and control group?n=10?.The model of atherosclerosis was established by high fat diet conaining 2%cholesterol and abdominal aortic balloon injury.Blood was drawn to exam total cholesterol?TC?,triglyceride?TG?,low density lipoprotein cholesterol?LDL-C?,high sensitivity C-reactive protein and matrix metalloproteinase-9.PET/CT was used to measure mean standardized uptake value?SUVmean?and maximum standardized uptake value?SUVmax?at week 8 and week 18respectively.Finally all rabbits were euthanized,and the aorta was treated with immunohistochemical staining.Serum index,SUV value,plaque area,plaque fibrous cap thickness,ratio of fibrous cap thickness to plaque area,and calcification area percentage were compared between the two groups.The correlation between SUVmean?SUVmax and arterial plaque area,the ratio of fibrous cap thickness to plaque area and the percentage of calcified area was analyzed.Results:There was no significant difference in TC,TG,LDL-C between the two groups at week 8and week 18.At the 18th week,hs-CRP?4.67±0.46 vs.6.21±0.93,P<0.01?,MMP-9?43.50±1.94 vs.60.24±3.62,P<0.01?and SUV?P<0.01?in pioglitazone group were lower than those in control group.At the end of the experiment,TG?1.70±0.90 vs.1.48±0.85,P<0.01?,hs-CRP?6.08±0.75 vs.4.67±0.46,P<0.01?,MMP-9?50.44±2.05 vs.43.50±1.94,P<0.01?in pioglitazone group.SUV value was lower than baseline level?P<0.01?.At the 8th week,the horizontal PET/CT fusion images of pioglitazone group and control group showed slight filling defect of aortic wall and a small amount of radioactive uptake.At week 18,the images of pioglitazone group were similar to those of week 8.The horizontal image of the control group showed obvious eccentricity filling defect and obvious radioactive uptake.SUVmean in the control group was significantly higher than that in the pioglitazone group?0.83±0.20 vs.0.63±0.14,P<0.01?.The SUVmax of control group was significantly higher than that of pioglitazone group?1.03±0.30 vs.0.77±0.18,P<0.01?.The plaque area and calcification area of the corresponding arteries in pioglitazone group were lower than those in control group,and the thickness of fibrous cap and the ratio of fibrous cap thickness to plaque area in pioglitazone group were higher than those in control group.Conclusion:The initiation and development of the calcification of the inflammation through the atherosclerotic plaque has an important effect on the progress of the plaque vulnerability and the early calcification of the vessel,the control of the level of inflammation can inhibit the development of atherosclerotic plaque vulnerability and vascular calcification.¹⁸F-FDG PET/CT,as an emerging molecular imaging technique,can be used to assess the vulnerability of atherosclerotic plaques and may prompt for early calcification of the vessel,And has a certain significance for guiding the clinical treatment.Glitazone,as a high-affinity peroxisome proliferator-activated receptor agonist,is a commonly used insulin sensitizer,has a strong anti-inflammatory effect,can be used for improving the vulnerability of the atherosclerotic plaque,and can be used for controlling the deve lopment process of the early calcification of the blood vessel.