Effect of post-mortem time on the biochemical composition of coronary arteries

Abstract

The effects of post-mortem autolysis on the biochemical composition of coronary intima-medias were studied by keeping the coronary arteries of 25 slaughterhouse pigs at +4°C for periods up to 7 days. The samples were analysed for DNA, total protein, collagen, glycosaminoglycans (GAGs), free and esterified cholesterol, triglycerides, phospholipid fractions, and fatty acid composition in various lipid classes. The content of sulphated GAGs decreased steadily, whereas that of hyaluronic acid remained unchanged. These alterations led to a significant decrease in the content of total GAGs and to an increase in the percentage of hyaluronic acid in total GAGs. The results indicate a continuous post-mortem degradation of arterial proteoglycans. After 7 days storage, there was a significant increase in the content of free fatty acids, and the composition of this fraction was changed by increases in the relative amounts of oleic and linoleic acids. These changes were accompanied by an increase in lysolecithin and a decrease in lecithin, which suggests a post-mortem action of arterial phospholipases. The results indicate that a useful way to assess the extent of autolysis in arterial wall is to measure the contents of free fatty acids and lysolecithin, the levels of which are normally very low in intact tissues other than plasma.