a1 Laboratory of Food Science Kyushu University School of Agriculture, Fukuoka 812, Japan
a2 Laboratory of Nutrition Chemistry. Kyushu University School of Agriculture, Fukuoka 812, Japan
The effects of dietary Korean pine (Pinus koraiensis)-seed oil containing a peculiar trienoic acid (cis-5, cis-9,cis-12-18:3, pinolenic acid, approximately 18%) on various lipid variables were compared in rats with those of flaxseed (Linum usitatissimum L.) oil, safflower (Carthamus tinctorius L.) oil and evening primrose (Oenothera biennis L.) oil under experimental conditions where the effects of different polyunsaturated fatty acids could be estimated. In Sprague-Dawley rats fed on diets containing 100 g fat and 5 g cholesterol/kg, the hypocholesterolaemic activity of pinolenic acid was intermediate between α-linolenic and linoleic acids. Analysis of the fatty acid composition of liver phosphatidylcholine indicated that, in contrast to α-linolenic acid, pinolenic acid does not interfere with the desaturation of linoleic acid to arachidonic acid. However, the effects on ADP-induced platelet aggregation and aortic prostacyclin production were comparable. When spontaneously hypertensive rats were fed on diets containing 100 g fat/kg but free of cholesterol, γ-linolenic and pinolenic acids, as compared with linoleic acid, increased prostacyclin production and tended to reduce platelet aggregation. In addition, pinolenic acid attenuated the elevation of blood pressure after 5 weeks of feeding. Thus, the results of the present studies indicate the beneficial effects of pinolenic acid on various lipid variables.
(Received June 22 1993)
(Revised November 12 1993)
(Accepted February 15 1994)