Effects of fish oil supplementation on acute ischemic brain injury in the rat

We studied the effects of long-term fish oil (FO) dietary supplementation on brain edema, polymorphonuclear neutrophil (PMN) infiltration, and infarct size in a rat stroke model. Rats were given regular rat chow with or without FO supplement (20 of total calories) for 7 weeks. Body weight did not differ between the two groups. In the FO group, an increase in eicosapentaenoic acid and a decrease in arachidonic acid content in hepatic phospholipids were significant in the phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine but not in the phosphoinositol fraction. Platelet activity reflected by serum thromboxane B2levels was reduced in the FO group. Postischemic brain edema and PMN infiltration were not different between the two groups. The infarct volume was significantly greater in the FO group (controls: 96 ±7 mm3, n 49; FO group: 124 ± 6 mm3, n 53; p0.0036). The greater ischemic brain injury in the FO-supplemented animals is probably related to the intraischemic hyperglycemia, which was worse in the FO group than in the control group (controls: 265 ± 19 mg/dl, n 14; FO group: 340 ± 18 mg/dl, n 16; p0.0079).