The aim of the present study was to evaluate the role of endothelial cell (EC) apoptosis in the development of pre-atherosclerotic intimal hyperplasia in different periods of experimental atherosclerosis.
Methods: Experimental atherogenic diet (Cholesterol, 200 mg/kg) in rabbits. Levels of lipid profile were measured in venous blood samples. Histological assays, IHC, TUNEL, transmission electron microscopy (TEM) were used.
Results: Apoptotic index (AI) of EC and intimal thickness (Lia) were significantly increased (p<0.05) in rabbits after 7, 15, 30 and 60 days of experimental atherosclerosis in comparison with control group, with peak AI level in 15 days of experiment (p=0.001). Period of experimental atherosclerosis and increase of AI were positively correlated (rs=0.71, p<0.001; rs=0.41, p=0.008, respectively) with L. ROC curve analysis displayed the largest diagnostic characteristics for L 7.82 (5.83-7.82) μm (AUC=0.893. p<0.001) after 7 days of experiment.
The results of TUNEL (TUNEL-positive nuclei and cytoplasm of EC) and TEM (CT, connective tissue, DZ, destruction zone, N, nucleus) are given on the Figures 1 (a, b, respectively).
Conclusion: Our results suggest that the formation of intimal hyperplasia might be a compensatory enlargement in response to EC apoptosis in cholesterol-fed rabbit aorta.