Changes in myocardial eicosanoid production following long-term dietary lipid supplementation in rats.
Recent studies demonstrate a strong link between the type of fat consumed and arrhythmogenesis and implicate altered production of eicosanoids as a potential mechanism. Thus, in a preliminary study designed to evaluate this hypothesis, five dietary lipid supplements--sunflower seed oil (SSO), chemically refined palm oil (PO I), physically refined palm oil (PO II), sheep fat (SF), and a 1:1 blend of SF and fish oil (SF-FO)--were compared for their effects on membrane-lipid composition and eicosanoid synthesis after a 12-mo pre-feeding period. Polyunsaturated fatty acids (PUFAs) of the myocardium showed significant alterations in response to dietary lipid treatment. Nevertheless, prostacyclin production was unaffected whereas both SF-FO and POI diets caused a significant inhibition of myocardial thromboxane A2 (TXA2). It is speculated that n-3 (omega-3) PUFAs may act as specific inhibitors of TXA2 synthetase whereas the PO I effect is unlikely to be mediated via fatty acids. These preliminary data are worthy of further investigation.
Abeywardena
M Y
MY
Division of Human Nutrition, CSIRO, South Australia.
McLennan
P L
PL
Charnock
J S
JS
D000818:Animals; D004041:Dietary Fats / Q000494:pharmacology*; D015777:Eicosanoids / Q000096:biosynthesis*; D011464:Epoprostenol / Q000096:biosynthesis; D005223:Fats / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis / Q000494:pharmacology; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013928:Thromboxane A2 / Q000096:biosynthesis
D004041:Dietary Fats; D015777:Eicosanoids; D005223:Fats; D005227:Fatty Acids; D013928:Thromboxane A2; D011464:Epoprostenol