ENDOTHELIUM MODIFIES THE ALTERED METABOLISM OF THE INJURED AORTIC-WALL

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  • 1 January 1981
    • journal article
    • research article
    • Vol. 102  (1) , 28-39
Abstract
Lipids, especially cholesterol and cholesteryl ester, preferentially accumulate in re-endothelialized, compared with de-endothelialized, areas of aorta. The hypothesis that this lipid accumulation results from alterations in arterial wall metabolism induced by injury and modified by endothelium was tested. Activities of the 2 cholestryl-ester-metabolizing enzymes acyl Co[coenzyme]A: cholesterol acyltransferase and acid cholesteryl esterase were assayed in uninjured aortas and in de-endothelialized and re-endothelialized areas of ballon-catheter-injured aortas from normocholesterolemic and hypercholesterolemic rabbits. Activities of marker enzymes for major cell organelles were assayed. Acyl CoA: cholesterol acyltransferase activity was similarly increased in re-endothelialized and de-endothelialized areas of injured aortas. Activity of acid cholesteryl esterase was increased but it was significantly less in re-endothelialized compared with de-endothelialized areas. Activities of several marker enzymes were changed in injured aortas, particularly in de-endothelialized compared with re-endothelialized areas. Injury apparently predisposes to general metabolic changes in the aorta that are modified by endothelium, and increased cholesteryl ester accumulation in re-endothelialized aortas occurs at least in part from increased synthesis and decreased hydrolysis.