Ischemic myocardial damage in spontaneously hypertensive rats (SHR) is enhanced after long-term feeding of an alpha-linolenic acid enriched diet

Abstract In this study the influence of long-term feeding of an alpha-linolenic acid (LNA) enriched diet on the sensitivity of SHR to catecholamine-induced myocardial injury was investigated. An enchanced ischemic vulnerability after LNA supplementation was observed as indicated both by a marked decrease of enzyme activities in the myocardium and by a pronounced elevation of plasma enzymes. Distinctly higher TBARS levels in heart tissue and plasma of LNA rich fed SHR suggest that an exaggerated lipid peroxidation might contribute to the increased ischemic vulnerability. Non-enzymatic lipid peroxidation is favoured by a feeding-provoked enrichment in highly unsaturated fatty acids in tissue phospholipids. Under such conditions of enhanced substrate availability for radical-induced lipid peroxidation an increased requirement for antioxidants can be assumed which might not sufficiently be met by tocopherol-supplementation in SHR because of their known defects in antioxidative defense mechanisms.