Effects of Intravenous ω‐3 and ω‐6 Fat Emulsion on Cytokine Production and Delayed Type Hypersensitivity in Burned Rats Receiving Total Parenteral Nutrition

<jats:p>Background: The effects of fat emulsions containing ω‐3 and ω‐6 polyunsaturated fatty acids (PUFAs) on fatty acid profile, cytokine production, and delayed type hypersensitivity (DTH) in burned rats receiving total parenteral nutrition (TPN) were investigated. Methods: A fat emulsion containing only eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was prepared (ω‐3 fat emulsion). Sprague‐Dawley rats were fed fat‐free chow for 2 weeks and were divided into three groups according to the contents of TPN. Groups C (n = 11) and C' (n = 14) received fat‐free TPN. Group ω6 received safflower oil emulsion containing linoleic acid (w‐6 PUFA) (n = 11). Group ω3 (n = 11) received safflower oil emulsion (19% of total caloric intake) and fat emulsion containing only EPA and DHA (1% of total calories). On day 5, all rats except for those in group C' were subjected to a 20% full‐thickness burn. Group C' did not receive burns. After 48 hours, the rats were killed. Results: The interleukin (IL)‐8 concentration was significantly 45% lower in group ω3 than in group C (p <.05). The IL‐10 concentration was significantly 15% lower in group ω3 than in group ω6 (p <.05). The IL‐6 concentration was increased in group w6 but not in group w3 when compared with group C. The IL‐6 and IL‐8 were not detected in group C'. Prostaglandin E<jats:sub>2</jats:sub> (PGE<jats:sub>2</jats:sub>) and thromboxane B<jats:sub>2</jats:sub> (TXB<jats:sub>2</jats:sub>) concentrations were increased by burn injury, but there were no significant differences among the burned groups. Cell‐mediated immunity was thus significantly decreased in burned groups (groups C, ω6, and ω3; p <.01). However, the decrease of DTH was smaller in group w3 and significantly greater when compared with groups C and w6 (p <.05). <jats:italic>Conclusions:</jats:italic> ω‐6 PUFAs increased serum inflammatory cytokine levels in a stressed state. ω‐3 fat emulsion reduced IL‐8 and IL‐10 levels and prevented immunosuppression in burned rats that were receiving TPN. <jats:italic>(Journal of Parenteral and Enteral Nutrition</jats:italic> <jats:bold>22:</jats:bold>363–367, 1998)</jats:p>