COLLAGEN SUBTYPE PATTERN IN NORMAL AND VARICOSE SAPHENOUS VEINS IN HUMANS

Our present study was to determine the collagen subtype pattern in the greater saphenous vein of the lower limb, obtained from 21 normal (ma croscopically and ultrastructurally non-varicose vein segments from no n-varicose subjects) and 37 varicose subjects, and to compare affected (macroscopically and ultrastructurally varicose segments from varicos e veins) vs. non-affected (macroscopically and ultrastructurally non-v aricose segments from varicose veins) segments (16). After elastase pr etreatment and partial pepsin digestion, types I, III & V collagens (C I, CIII, CV) were extracted selectively by differential salt precipita tion and measured quantitatively in samples obtained from normal and v aricose saphenous veins - either affected or unaffected segments. Sign ificant elevations of water (p < 0.05) and collagen type I [CI] (p < 0 .01) content in varicose veins (both affected and unaffected segments) as compared with normal saphenous veins were observed. The collagen t ype III (CIII) and collagen type V (CV) content of varicose veins were found to be slightly reduced as compared to normal veins and conseque ntly the CI/(CIII + CV) ratio in varicose veins increased significantl y (p < 0.02) as compared to normal veins. Elevation of the CI/(CIII CV) ratio in varicose veins may cause considerable weakening of the ve nous wall, further supporting the ''weak wall'' theory of varicose vei n etiology.