Levy, E.; Thibault, L.; Garofalo, C.; Messier, M.; Lepage, G.; Ronco, N.; Roy, C. C.
Author Affiliation :
Gastroenterology-Nutrition Research Unit, Centre de Recherche Pédiatrique, Hôpital Ste-Justine, Montreal, Quebec, Canada.
Journal of Lipid Research
The lipid profile as well as the concentration, composition and metabolism of lipoproteins were examined in rats rendered deficient in essential fatty acids (EFA) during 12 weeks. Changes in plasma fatty acids mainly induced an increase of palmitoleic (16:1 n-7) and eicosatrienoic (20:3 n-9) acids, while linoleic (18:2 n-6), arachidonic (20:4 n-6), linolenic (18:3 n-3) and docosahexaenoic (22:6 n-3) acids were decreased. The results show increased concentrations of free fatty acids (FFA) (P<0.001), triacylglycerols (P<0.001), total cholesterol (P<0.02), free cholesterol (P<0.005), and phospholipids (P<0.05) when compared with values in pair-fed controls. Similar cholesteryl esters values were found in the 2 groups, and phosphatidylcholine-sterol acyltransferase activity (nmol/100 µl plasma per h) (8.98±1.44 vs. 8.72±0.50) did not differ. Postheparin extrahepatic lipoprotein lipase (LPL) activity was decreased (P<0.002) (5.96±0.29 vs. 7.29±0.68 µmol FFA/ml per h) and could account for the hypertriglyceridaemia as well as for the relative triacylglycerol enrichment of very-low-density lipoprotein, intermediate-density lipoprotein, and low-density lipoprotein particles. This enzymic depletion of LPL was mainly due to the adipose tissue, as a higher value (P<0.001) of hepatic lipase (325.8±16.0 vs. 130.8±9.5 nmol FFA/mg protein per h) was found in liver acetone powder extracts. It is suggested that the lipoprotein abnormalities induced by EFA deficiency can be largely attributed to decreased lipoprotein lipase activity coupled with an increase of hepatic lipase.
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Organism descriptor(s) :
blood, blood lipids, deficiency, Essential fatty acids, lipoprotein lipase, lipoproteins, lipid metabolism disorders
diacylglycerol lipase, dyslipidaemia, dyslipidemia, fat metabolism disorders
Broader term(s) :
Muridae, rodents, mammals, vertebrates, Chordata, animals, eukaryotes