Effect of the dietary alpha-linolenate/linoleate balance on leukotriene production and histamine release in rats.
Rats were fed semi-purified diets supplemented either with safflower seed oil rich in linoleate (18:2n-6) or with perilla seed oil rich in alpha-linolenate (18:3n-3) through two generations. In the major phospholipids of polymorphonuclear leukocytes (PMNs), the proportions of n-6 polyunsaturated fatty acids (18:2, 20:4, 22:4 and 22:5) were higher but those of n-3 acids (20:5, 22:5 and 22:6) were lower in the safflower group than in the perilla group. When stimulated with a calcium ionophore, the PMNs from the safflower group produced 27% more leukotriene (LT)B4 than those from the perilla group. The formation of LTB5 which has biological activities less than 1/10 those of LTB4, was negligible in the safflower group but was 40 ng/10(7) PMN cells in the perilla group. The amount of the total LTB formed in the perilla group tended to be more than in the safflower group. The formation of SRS-A (slow-reacting substances of anaphylaxis) by PMNs was determined by measuring the spasmogenic activities of LTs on guinea pig ileum. SRS-A activity was 59% higher in the safflower group than in the perilla group. In contrast, histamine release from rat peritoneal mast cells was not significantly different between the two groups. Thus, the increasing the alpha-linolenate/linoleate ratio of diets results in the decreased formation of LTs derived from 20:4n-6 in PMNs. This may be beneficial in lowering the severity of allergic and inflammatory responses caused by LTs, and thereby shifting the pathological symptoms to normal self-defense mechanism.
Hashimoto
A
A
Faculty of Pharmaceutical Sciences, Nagoya City University, Japan.
Katagiri
M
M
Torii
S
S
Dainaka
J
J
Ichikawa
A
A
Okuyama
H
H
D000818:Animals; D004041:Dietary Fats / Q000494:pharmacology*; D006636:Histamine Release / Q000187:drug effects*; D007975:Leukotriene B4 / Q000096:biosynthesis*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology*; D008042:Linolenic Acids / Q000494:pharmacology*; D008407:Mast Cells / Q000187:drug effects; D051381:Rats; D011921:Rats, Inbred WKY; D012450:Safflower Oil / Q000494:pharmacology; D017962:alpha-Linolenic Acid
D004041:Dietary Fats; D008041:Linoleic Acids; D008042:Linolenic Acids; D017962:alpha-Linolenic Acid; D007975:Leukotriene B4; D012450:Safflower Oil; D019787:Linoleic Acid