Fish oil dietary supplementation reduces Ia expression in rat and mouse peritoneal macrophages.
Preliminary studies suggest that administration of fish oil fatty acids may be beneficial in several immunological diseases; therefore, we studied the effect of fish oil dietary supplementation on the expression of Ia in stimulated murine peritoneal macrophages. Rats (n = 19) and mice (n = 27) on standard rodent feeding were separated in experimental (E) and control (C) groups that received fish oil or saline solution, respectively, daily for 4 weeks by esophageal gavage. Cholesterol serum levels were significantly lowered by fish oil (E vs C, P less than 0.01). E and C groups were injected intraperitoneally with Listeria monocytogenes (LM) and peritoneal cells were harvested 4 and 7 days after infection. Decreased expression of Ia induced by LM was found in rats (C = 49.68 +/- 5.09%, E = 16.95 +/- 4.3%, P less than 0.01) and mice (C = 47.38 +/- 7.63%, E = 26.66 +/- 1.92%, P less than 0.01). Animals with a more pronounced depression of serum cholesterol (reduction of 44.04 +/- 1.52% of baseline levels) had more depression of Ia expression (6.47 +/- 1.22%, P less than 0.001 vs control). Reduction of Ia expression was not related to PGE2 production by peritoneal cells. Reduction of Ia expression by fish oil could induce down-regulation of antigen presentation and alloreactivity.
Mosquera
J
J
Instituto de Investigaciones Clínicas, Facultad de Medicina, Universidad de Zulia, Maracaibo, Venezuela.
Rodríguez-Iturbe
B
B
Parra
G
G
D000818:Animals; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D015232:Dinoprostone / Q000096:biosynthesis; D005395:Fish Oils / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis*; D008089:Listeria monocytogenes / Q000276:immunology; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D010529:Peritoneal Cavity / Q000166:cytology; D051381:Rats; D011917:Rats, Inbred Lew
D004042:Dietary Fats, Unsaturated; D005395:Fish Oils; D000949:Histocompatibility Antigens Class II; D015232:Dinoprostone