ENDOGENIC NONENZYMATIC ANTIOXIDATIVE SYSTEM OF POLYESTER GRAFTS DURING THEIR HEALING

Objective, Non-enzymatic low-molecular antioxidants are one of the imp ortant mechanisms which protect cells against the toxic effect of oxyg en, The aim of the present study was to determine the content of gluta thione, glutathione reductase, and ascorbic acid in the principal laye rs of polyester grafts. Interventions and measures. The experiments we re carried out on 24 mongrel dogs, in which polyester double velour DA LLON grafts were implanted, Seven days, 1, 4, and 12 months after the operation the grafts were excised, The following were determined: glut athione content by use of a GSH-400 system, glutathione reductase acti vity by the method of Langdon and Mite, and ascorbic acid content by t he Kyaw method, Results. It was found that the glutathione content in the graft neointima was 33% lower, in the graft neo-media higher durin g the first 4 months, in the neo-adventitia 50% lower after 4 months t han in the corresponding layers of the aorta (p < 0.01), The activity of glutathione reductase was significantly higher in all the graft lay ers during 12 months' observation than in the normal aorta layers. The ascorbic acid content of the graft layers was lowest 7 days after the implantation, and then in time increased so that 12 months after the operation it reaches its highest values, Conclusions. Our study shows that low non-enzymatic antioxidative potential is not capable of prote oting the newly forming graft layers, particularly the neointima, agai nst oxygen toxicity, Thus, it would be beneficial to administer antiox idants (vitamin C, vitamin E, and N-acetylcysteine).