Comparison of deposits of versican, biglycan and decorin in saphenous vein and internal thoracic, radial and coronary arteries: correlation to patency.

BACKGROUND: Matrix proteoglycans versican, biglycan and decorin are important determinants of vessel-wall structure and pathology. Thickened myxoid intimas typical of restenosis and early atherosclerosis are enriched in versican and biglycan, proteoglycans that promote proliferation and migration of smooth muscle cells and bind lipoproteins. In contrast, compact fibrous intimas are characterized by decorin.
OBJECTIVE: To compare the distribution patterns of these matrix proteoglycans, and changes induced by organ culture in coronary artery, saphenous vein, internal thoracic artery (ITA), and radial artery, and correlate differences to patency.
METHODS: Vessels were collected at the time of bypass surgery and heart transplantation and either fixed for immunohistochemistry or prepared for organ culture. Vessels in culture were labelled with [3H]-glucosamine and processed for autoradiography and immunohistochemistry. Distribution patterns for proteoglycans and radio-labelling were determined morphometrically.
RESULTS: Distribution profiles in coronary artery and saphenous vein were similar, with relatively high levels of subendothelial versican and biglycan and low levels of decorin. In culture subendothelial incorporation of [3H]-glucosamine and immunostaining for versican and biglycan, but not decorin, were significantly increased. In contrast, the thin intima of the ITA was relatively enriched in decorin compared with the medial layers and in culture intimal staining for decorin increased markedly compared with a modest increase for biglycan and no change for versican. There was an even distribution in radial artery of all three proteoglycans across the intima without subendothelial accumulations. In culture there was an increase in staining intensity for proteoglycans of the radial artery. Neither the ITA nor radial artery exhibited an increase in subendothelial incorporation of [3H]-glucosamine in culture.
CONCLUSIONS: The distributions of proteoglycans, and responses to culture correlate to the known differences in patency between grafted saphenous vein and ITA and predict that the radial artery will outperform the saphenous vein but might not be as good as the ITA for long-term patency.