Dietary ingestion of (n-3) PUFA alters the production of eicosanoids and can suppress chronic inflammatory and autoimmune diseases. The extent of changes in eicosanoid production during an infection of mice fed a diet high in (n-3) PUFA, however, has not, to our knowledge, been reported. We fed mice a diet containing either 18% by weight soybean oil (SO) or a mixture with fish oil (FO), FO:SO (4:1 ratio), for 2 wk and then infected them with Borrelia burgdorferi. We used an MS-based lipidomics approach and quantified changes in eicosanoid production during Lyme arthritis development over 21 d. B. burgdorferi infection induced a robust production of prostanoids, mono-hydroxylated metabolites, and epoxide-containing metabolites, with 103 eicosanoids detected of the 139 monitored. In addition to temporal and compositional changes in the eicosanoid profile, dietary FO substitution increased the accumulation of 15-deoxy PGJ(2), an antiinflammatory metabolite derived from arachidonic acid. Chiral analysis of the mono-hydroxylated metabolites revealed they were generated from primarily nonenzymatic mechanisms. Although dietary FO substitution reduced the production of inflammatory (n-6) fatty acid-derived eicosanoids, no change in the host inflammatory response or development of disease was detected.

OBJECTIVE To evaluate a feline-specific multiplex, bead-based assay system for detection of recombinant and native proteins in serum samples and in EDTA-treated and heparinized plasma samples. SAMPLE Serum samples and EDTA-treated and heparinized plasma samples from 30 sick cats and 9 healthy client-owned cats and heparinized whole blood samples from 5 healthy purpose-bred cats. PROCEDURES Ability of the assay system to detect 19 recombinant and native immunologically active proteins in plasma and serum samples from healthy and purpose-bred cats was evaluated via spike-and-recovery tests, assessments of inter- and intra-assay variation, linearity results, and leukocyte stimulation. Effects of various concentrations of heparin and serum matrix solution on percentages of analytes recovered were also evaluated. Analyte concentrations in samples from healthy and sick cats were measured and compared between groups. RESULTS Percentages of analytes recovered were unsatisfactory for most assays. Serum and heparinized plasma samples yielded better recovery results than did EDTA-treated plasma samples. Use of serum matrix solution did not improve results. Use of heparin concentrations greater than the recommended range affected the results. Linearity of results was difficult to assess because of the poor recovery. For the analytes that were recovered sufficiently for assessment, linearity appeared to be reasonable despite the limited detection. CONCLUSIONS AND CLINICAL RELEVANCE Poor percentages of analytes recovered and adverse effects of sample protein matrix limited the usefulness of the multiplex, bead-based assay system for measurement of immunologically active proteins in solutions with high protein content; however, recovery results were fairly linear, potentially allowing evaluation of feline plasma or serum samples with high analyte concentrations.

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Dietary fish oil is suggested to alleviate a variety of inflammatory disorders by altering eicosanoid production. However, the extent of changes resulting from a diet high in omega-3 fatty acids is unknown, and any benefits resulting from these changes are unsubstantiated. Several studies conclude that the lack of phenotypic effects of fish oil result from an inability to consume sufficient quantities for any benefits to be evident. We fed mice either a control diet containing 18% by weight soybean oil or fish oil and infected the mice with Borrelia burgdorferi in order to quantify changes in temporal eicosanoid production throughout the course of disease. Using a lipidomics approach, we detected dramatic temporal and compositional changes in the majority of the 103 eicosanoids monitored. LOX metabolites produced in fish oil-fed mice were primarily generated non-enzymatically, and arachidonic acid metabolism was shunted from PGE2 synthesis to PGD2 synthesis resulting in the production and accumulation of 15d-PGJ2. Despite the fact that the fish oil diet led to a highly anti-inflammatory microenvironment, mice were able to mount an immune response and clear infection as well as mice fed a control diet. This study confirms that a diet high in fish oil results in a microenvironment with high anti-inflammatory potential but does not necessarily affect the ability of the organism to mount an effective immune response to infection with Borrelia burgdorferi.