Secretory phospholipase A2 and phospholipids in neural membranes in an experimental epilepsy model

OBJECTIVES: Previous studies have revealed an increase in several forms of phospholipase A2 activity associated with cell injury, but the secretory form of phospholipase A2 has not previously been studied in neurological disorders. We investigated the influence of seizures on secretory phospholipase A2 and phospholipid breakdown in synaptosome fractions prepared from rat hippocampus, cortex and cerebellum in pentylenetetrazol-induced epilepsy. MATERIAL AND METHODS: Secretory phospholipase A2 concentration was measured by a photometric enzyme immunoassay. The synaptosomes underwent extraction, and the phospholipids fractions for phosphatidylcholine, phosphatidylethanolamine and lysophosphatidylcholine were recovered from the thin layer chromatography plates. The amount of each phospholipid was quantified using the amount of recovered phosphate in each phospholipid spot. RESULTS: Secretory phospholipase A2 concentration was found to be significantly higher in the epileptic group when compared with the control group. The amounts of phospholipids were found to be highly variable in different brain regions. CONCLUSION: Our results suggest that epileptic seizures enhanced phospholipid breakdown and induced alterations in the distribution of phospholipids in different brain regions.