Abstract
The continuous exposure to blood components, including pro-oxidants, makes the blood vessel wall susceptible to oxidative stress and free-radical-mediated reactions.The aim of this study was to determine the ability of reactive oxygen metabolite generation, expressed by the content of malonaldehyde (MDA) and 4-hydroxyalkenals in principal layers of polyester grafts during 12 months' observation.
The experiments were carried out on 24 mongrel dogs, in which polyester grafts were implanted into abdominal aorta. Seven days and 1, 4, and 12 months after the operation the grafts were excised. The MDA and 4-OH-alkenal concentrations were determined by the LPO-586 method (Bioxytech, France).
It was found that the MDA concentration in the graft neointima was much higher than in the aorta in the early phase after the operation (P<0.01). With the passage of time this concentration decreased and after 4 months was similar to the values of the normal aorta. On the other hand the MDA concentration in the neomedia and neoad ventitia was much higher than in their aorta counterparts and became even higher in later periods (P<0.01). (continued on next page)
The investigations indicate that the generation of large amounts of lipid peroxides in graft neointima occurs only in the early postoperative period. However, intensive lipid peroxidation in neomedia and neoadventitia was observed throughout the whole exper iment. These changes can suggest that the reactive oxygen metabolites in graft principal layers are generated by neutrophils, while endothelial cells are of less importance.
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