Page 1374 - Veterinary Immunology, 10th Edition

Box 41.2
VetBooks.ir Immunosuppressive Fatty Acids

Inflammation is mediated by many different molecules, including
lipids such as the leukotrienes and prostaglandins. Certain
polyunsaturated fatty acids are the precursors of these prostanoids

and so can regulate their production. Omega-6 fatty acids such as
arachidonic acid tend to be proinflammatory, whereas the omega-3
fatty acids such as eicosapentaenoic acid and docosahexaenoic acid

tend to have antiinflammatory effects since they suppress
eicosanoid production. The omega-3 fatty acids also promote
production of resolvins and protectins. These fatty acids suppress
NF-κB signaling and inhibit the production of inflammatory
cytokines such as IL-1 and TNF-β. They tend to be

immunosuppressive as well, suppressing B, total T, and Th cells in
cat skin. They do not appear to influence Tc or NK cell populations,
IL-2 responses, delayed hypersensitivity, or immunoglobulin

levels. The feeding of oils containing omega-3 fatty acids such as
fish oil, evening primrose oil, and flaxseed oil may therefore reduce
skin inflammatory responses and be of clinical benefit in the
treatment of allergic skin diseases, especially atopic dermatitis.
They may also be of benefit in the treatment of inflammatory bowel

disease.

Rutherfurd-Markwick KJ, Hendriks WH, Morel PCH, Thomas DG: The potential for
enhancement of immunity in cats by dietary supplementation, Vet Immunol Immunopathol
152:333-340, 2013.

Cytotoxic Drugs

Cytotoxic drugs inhibit cell division by blocking nucleic acid
synthesis and activity. The major cytotoxic drugs currently in use
are alkylating agents, folic acid antagonists, and DNA synthesis

inhibitors.

Alkylating Agents

Alkylating agents cross-link DNA helices, preventing their
separation, and thus block cell division. The most important of

these is cyclophosphamide (Fig. 41.2). Cyclophosphamide is toxic

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