title: Lifelong exposure to dietary fish oil alters macrophage responses in Walker 256 tumor-bearing rats.
abstract: Supplementation of the diet with fish oil (FO) decreases growth of the Walker 256 tumor and decreases the cachexia associated with tumor-bearing. The mechanisms by which FO inhibits tumor growth and cachexia are unknown. Macrophages are very important in host defence against tumors since they produce several anti-tumor agents which in turn have been shown to be modified by dietary FO, but rarely in the setting of tumor bearing and never in relation to lifelong exposure. In this study, we compared the effects of supplementation of the diet of pregnant and lactating rats and subsequent supplementation of the offspring with coconut fat or FO on macrophage activities involved in anti-tumor defence. FO supplementation was able to induce an increase in phagocytosis, in O2-, H2O2, nitric oxide, and TNF-alpha production by macrophages and in lysosomal volume in non-tumor-bearing rats. However, phagocytosis, production of O2- and H2O2 and lysosomal volume were not affected by the FO diet when rats were bearing tumors, although nitric oxide production was higher in these animals. It appears that tumor bearing activates the innate immune system and that dietary FO has little effect on innate immunity in the presence of Walker 256 tumors. Thus, it is still unclear how FO decreases the growth of Walker 256 tumors and the associated cachexia.
authors.affiliation: Department of Physiology, Biological Sciences Building, Federal University of Paraná, 81540-990 Curitiba-PR, Brazil.
authors.forename: Sandro J R
authors.initials: SJ
authors.lastname: Bonatto
authors.forename: Alessandra
authors.initials: A
authors.lastname: Folador
authors.forename: Júlia
authors.initials: J
authors.lastname: Aikawa
authors.forename: Ricardo K
authors.initials: RK
authors.lastname: Yamazaki
authors.forename: Nathalia
authors.initials: N
authors.lastname: Pizatto
authors.forename: Heloisa H P
authors.initials: HH
authors.lastname: Oliveira
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Vecchi
authors.forename: Rui
authors.initials: R
authors.lastname: Curi
authors.forename: Philip C
authors.initials: PC
authors.lastname: Calder
authors.forename: Luiz C
authors.initials: LC
authors.lastname: Fernandes
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D002279:Carcinoma 256, Walker / Q000276:immunology*; D002478:Cells, Cultured; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000494:pharmacology*; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage* / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D004042:Dietary Fats, Unsaturated; D005395:Fish Oils; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; D009569:Nitric Oxide; D006861:Hydrogen Peroxide