Changes in levels of apoptosis in the walls of different segments of great saphenous varicose veins.

Abstract

Disordered programmed cell death may play a role in the development of superficial venous incompetence. We have determined the number of cells undergoing apoptosis and the alterations in the apoptotic level in the wall of different segments of the great saphenous varicose vein. Twenty-one varicose great saphenous veins (VGSVs) (varicose group) and 12 normal great saphenous veins (GSVs) (control group) were collected, and the apoptosis level in the upper, middle, and lower segments were immunohistochemically stained with antibodies (anti-Bax and anti-Bcl-xl). Apoptosis was evaluated by the TUNEL assay and immunofluorescence staining. The morphology of apoptotic cells was observed with an electron microscope. Quantitative analysis showed that the apoptotic ratios in venous walls (intima and media) of the varicose group were significantly lower than the corresponding regions in the control group (all P < 0.05). A significantly higher apoptotic rates of the venous walls was observed in control group within the upper compared with the lower segment (P < 0.05). Significantly higher positive proteins expression rates of Bcl-xl/Bax were also detected in the VGSVs compared with the GSVs within the three segments, respectively (P < 0.01). Electron microscopic observations confirmed that endothelial and smooth muscle cells in varicose and normal vein walls exhibited apoptotic morphologic features, such as fuzzy mitochondrial cristae, medullary changes, and margination of the nuclear chromatin. VGSV walls were found to have a significant decrease in apoptotic rate compared with that of GSVs. The rate of apoptosis in the intima and media within the upper segment was increased more than the middle and lower segments in the GSVs. Our findings confirm that programmed cell death is down-regulated in primary varicose veins.