Wide variety of stimuli induces apoptosis of endothelial cells (EC), and the apoptosis can be an important mechanism of vascular injury, resulting in progression of atherosclerosis.Purpose
This study was designed to evaluate TUNEL on the touch smears in determination of role of EC apoptosis in atherogenesis.Method
Segments of aorta and coronary arteries were obtained from 7 autopsied subjects who died of atherosclerosis. Touch smears were taken from intimal surface in different stages of atherogenesis. We used Von Willebrand factor (fvW) as an immunocytochemical marker to identify EC. EC apoptosis was assessed by TUNEL. The parts of aorta without atherosclerosis were used as control samples.Results
During the identification EC by immunocytochemical typing cytoplasm of EC was stained positive to fvW both in control samples and in samples of persons with atherosclerosis. Cytoplasm was stained non-uniformly, intensity of staining was traced from poorly expressed to the bright. TUNEL-positive EC were found at all stages of atherogenesis. Typical arrangement of chromatin in the form of a horseshoe on periphery of EC nucleus was detected. We took note of TUNEL-positive nucleuses and cytoplasm of EC individual cases, where cytoplasm thus got fine-grained structure. EC with coarse-grained TUNEL-positive cytoplasm and oxyphilic TUNEL-negative nucleus were marked. The figure shows the brown staining of EC marker fvW and the TUNEL-positive nucleuses of EC.Conclusion
The presence of the TUNEL-positive EC confirm a possible role of apoptosis in disturbance of their physiological function and creation of additional conditions to progression of atherosclerosis. Staining of EC cytoplasm in touch smears, possibly, testifies to the late stages of apoptosis.