PubMed1976
Dacron arterial prostheses, treated or not with biopolymers (gelatin, glycosaminoglycans) were implanted in the abdominal aorta of dogs and the connective tissue synthetised inside and outside the prosthesis was studied. After 3 and 9 months of implantation the prosthesis, a joining portion and a piece of aorta were excised and put in organ culture with 14C-lysine for 3 days. Representative macromolecular extracts were then obtained by a "chemical dissection" procedure. The radioactivity and the chemical composition of these extracts was studied. The DNA content of the prosthesis was higher than that of the adjacent aorta showing a dense cellular repopulation of the prosthesis. This was confirmed by histology also which revealed the presence of a newly formed limiting elastic membrane and the presence of numerous elastic fibrils. Collagen, elastin and glycosaminoglycans could be detected in the macromolecular extracts showing that the cells which repopulated the prosthesis expressed a complete biosynthetic capacity as far as matrix macromolecules are concerned. The distribution of proteins in the extracts was as follows: 4% of total proteins were extracted in a 1M CaCl2-buffer 80% of total proteins in the collagenase extracts, 10% in the 6M urea extract. Only 0,2% of proteins were in the final elastase extract, 10 times less than in the joining aorta fragment. The proportion of the other proteins was similar in aorta and in the prosthesis as well as the chemical composition (hexosamine and hydroxyproline content) of the extracts. The proportion of collagenase-extractable proteins decreased with the time of implantation (from 3 to 9 months) and the proportion of urea-extractable proteins increased. This type of modification is similar to that found in aging aorta wall. 14C-lysine was actively incorporated in all macromolecular fractions studied. The incorporation pattern of the prothesis tissue was similar to that found for the joining host aorta, showing a similar regulatory tendency for matrix macromolecules. It appears therefore that a valid hemocompatible vascular type of connective tissue can be synthesised on the dacron arterial prosthesis and nature of this connective tissue can be influenced by previous biopolymer treatment of the synthetic prosthesis. The described procedure (incorporation of labelled precursors in organ culture) appears to be a valid method for the exploration of the regulatory processes underlying the synthetic capacity for matrix macromolecules of the newly formed tissue in the synthetic prosthesis.