INFLUENCE OF UNSATURATED DIETARY FATTY-ACIDS ON THE DISTRIBUTION OF CHOLESTEROL IN THE LIPOPROTEIN FRACTIONS AND ON SERUM-LIPIDS OF RATS

In six groups Of nine young Sprague-Dawley rats each, the coconut fat used in the basal diet (group I) was replaced to 60% by pure oleic aci d (group II) or linoleic acid (group III), respectively, by 0.6% of a- linolenic acid (IV), eicosatrienoic acid (V) and eicosapentaenoic acid (VI). A 60% replacement of the coconut fat in the basal diet by pure oleic acid, respectively, by 0.6% of eicosapentaenoic acid or eicosatr ienoic acid significantly decreased the total cholesterol concentratio n in serum by 21% (HDL -28%; LDL -15%; VLDL -48%), respectively, 19% ( HDL -12%; LDL -42%; VLDL +69%) or 15% (HDL -11%; LDL -21%) and the tot al free cholesterol concentration by 22% (HDL -27%), respectively, 41% (HDL -31%; LDL -66%) or 23% (HDL -21%; LDL -31%). The substitution of the coconut fat by 60% oleic acid or 0.6% alpha-linoleic acid had no influence on the total and total free cholesterol concentration in ser um, though in the LDL-fraction a significant decrease of cholesterol c ould always be found. The concentrations of free fatty acids in serum were not influenced by the unsaturated dietary fatty acids while the p hospholipid concentration was reduced by linoleic acid (-15%) and by e icosapentaenoic acid (-18%). The triglyceride content in serum was dec reased by linoleic acid (-29%) and by eicosatrienoic acid (-25%).