Peroxisomes in mice fed a diet supplemented with low doses of fish oil.
The influence of low dietary doses (0.1 and 0.8% w/w) of a commercial fish oil preparation on peroxisomes in normal mice was studied and compared to the known strong inductive effects of high (10%) fish oil diets. Low fish oil doses were chosen to supply the mice with a concentration of docosahexaenoic acid, which was beneficial to patients with a peroxisomal disease. Peroxisomes were evaluated by cytochemical, morphometric, and enzymological techniques. The 0.1% fish oil diet had no effect on peroxisomes in liver, heart, and kidney even after prolonged treatment. The 0.8% diet did not change the peroxisomal number nor the catalase (EC 1.11.1.6) activity in the liver. Hepatic peroxisomal beta-oxidation, however, was increased by 50% after 14 d. This was accompanied by reduced peroxisomal size. The 0.8% diet also caused a small increase (+25%) in myocardial catalase activity. No effect was observed in kidneys. Our results indicate that in mice a low (< 0.8%) dietary fish oil dose has no or only a slight effect on hepatic peroxisomal beta-oxidation. This may be of particular interest to patients with a peroxisomal fatty acid beta-oxidation defect and who display a severe deficiency of docosahexaenoic acid--diets supplemented with low fish oil doses will improve the docosahexaenoic acid level without adding a strong load to the disturbed fatty acid metabolism.
D000818:Animals; D002374:Catalase / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D005395:Fish Oils / Q000008:administration & dosage*; D007668:Kidney / Q000201:enzymology / Q000648:ultrastructure; D008099:Liver / Q000201:enzymology / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008830:Microbodies / Q000378:metabolism / Q000648:ultrastructure*; D009206:Myocardium / Q000201:enzymology / Q000648:ultrastructure; D010084:Oxidation-Reduction
D004042:Dietary Fats, Unsaturated; D005395:Fish Oils; D004281:Docosahexaenoic Acids; D002374:Catalase