The interrelated effects of n-6/n-3 and polyunsaturated/saturated ratios of dietary fats on the regulation of lipid metabolism in rats.
The effects of various n-6/n-3 (0.45-9.31) and polyunsaturated/saturated (P/S; 0.25-6.08) ratios of dietary fatty acids on various lipid parameters were studied in rats using a combination of palm oil, safflower oil, soybean oil and perilla oil. When the n-6/n-3 ratio was changed while maintaining a constant P/S ratio (1.2), the concentration of serum cholesterol tended to increase linearly with the increasing n-6/n-3 ratio, whereas liver cholesterol tended to decrease. Serum triglyceride level increased linearly up to a n-6/n-3 ratio of approximately 5, whereas liver triglyceride was not influenced. When the n-6/n-3 ratio was kept relatively constant (5.6-6.4), serum and liver cholesterol levels decreased up to a P/S ratio of approximately 2, whereas serum triglyceride tended to be low below this value. The ratio of arachidonate to linoleate in tissue phosphatidylcholine (PC) was also influenced by the n-6/n-3 and P/S ratios; it increased up to a n-6/n-3 ratio of approximately 4, whereas it decreased up to a P/S ratio of approximately 2. The percentage of eicosapentaenoic and docosahexaenoic acid (n-3) in tissue phosphatidylcholine was positively related to dietary n-3 fatty acid levels. Prostacyclin (PGI2) production by thoracic aorta reached a plateau at a n-6/n-3 ratio approximately 5, whereas it tended to decrease with an increasing P/S ratio. Platelet production of thromboxane A2 exhibited a parabola-like pattern with a peak value at a n-6/n-3 ratio of approximately 2, whereas it was independent of the P/S ratio.(ABSTRACT TRUNCATED AT 250 WORDS)
Lee
J H
JH
Laboratory of Nutrition Chemistry, Kyushu University School of Agriculture, Fukuoka, Japan.
Fukumoto
M
M
Nishida
H
H
Ikeda
I
I
Sugano
M
M
D000273:Adipose Tissue / Q000032:analysis; D000818:Animals; D001011:Aorta / Q000032:analysis; D002784:Cholesterol / Q000032:analysis; D004041:Dietary Fats / Q000494:pharmacology*; D015777:Eicosanoids / Q000032:analysis / Q000096:biosynthesis; D005227:Fatty Acids / Q000008:administration & dosage* / Q000032:analysis / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage*; D050356:Lipid Metabolism; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000032:analysis / Q000378:metabolism; D008297:Male; D010713:Phosphatidylcholines / Q000032:analysis; D010938:Plant Oils / Q000008:administration & dosage; D051381:Rats; D011919:Rats, Inbred Strains; D014280:Triglycerides / Q000032:analysis
D004041:Dietary Fats; D015777:Eicosanoids; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D008055:Lipids; D010713:Phosphatidylcholines; D010938:Plant Oils; D014280:Triglycerides; D002784:Cholesterol