1. Daily DHA injections raise seizure thresholds and blood but not brain free DHA levels in rats

Abstract

Background Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (n−3 PUFA), which has previously shown to have anticonvulsant activity rats. The purpose of the present experiment was: (1) to confirm that sub-chronic DHA raises thresholds in the maximal pentylenetetrazole (PTZ) model, and (2) to determine whether that increase is correlated with an increase in serum and brain DHA Methods Animals received daily i.p. injections of 50 mg/kg of DHA, 50 mg/kg DHA ethyl ester (DHA EE) or volume-matched vehicle for 14 days. On day 15, one group of animals was seizure tested in the maximal PTZ model, while another group provided blood and brain samples. Brain samples were obtained after the animals were euthanized via head-focused microwave fixation. Lipid analyses were performed on both blood and brain. Since the DHA and DHA EE groups did not differ significantly, they were combined for statistical analyses. Results In the maximal PTZ model, DHA significantly increased seizure latency by approximately 3 fold, as compared to vehicle-injected controls. This increase in seizure latency was associated with an increase in serum unesterified DHA levels. Total brain DHA and brain unesterified DHA, however, were not significantly different between treatment and control groups.