FISH-OIL INCREASES THE RELEASE OF TUMOR-NECROSIS-FACTOR AND INTERLEUKIN-6, AND HAS NO EFFECT ON THE INCIDENCE OF MULTIPLE ORGAN FAILURE IN RATS WITH PERITONITIS

Objective: To find out if fish oil given intraperitoneally would cause a reduction in the release of tumour necrosis factor and interleukin- 6 in abdominal exudate and brood (experiment A), and if it reduces the incidence of organ failure in rats with peritonitis (experiment B). D esign: Laboratory experiment. Setting: University animal laboratory. M aterial: Thirty-six selectively decontaminated rats in each experiment . Interventions: All rats were pretreated with 2 ml fish oil, lecithin , or saline, intraperitoneally for one or six weeks before intraperito neal injection of zymosan. Experiment A: Samples of abdominal exudate and plasma were taken regularly for 24 hours after the zymosan had bee n given. Experiment B: Clinical, biochemical, and histological variabl es were measured over a 12-day period after the zymosan had been given . Main outcome measures: Experiment A: Concentrations of tumour necros is factor and interleukin-6 in abdominal exudate and plasma. Experimen t B: Incidence of multiple organ failure. Results: Experiment A: Conce ntrations of tumour necrosis factor and interleukin-6 in abdominal exu date and plasma were significantly higher in rats pretreated with fish oil, compared with control rats. This effect was more pronounced afte r six weeks of pretreatment. Experiment B: There were no significant d ifferences between the groups for any variable. Conclusion: Fish oil g iven intraperitoneally increased rather than reduced local and systemi c release of tumour necrosis factor and interleukin-6, and did not red uce the incidence of organ failure in rats with sterile peritonitis.