Characterization and location of secretory phospholipase A2 groups IIE, V, and X in the rat brain

Secretory phospholipases A 2 (sPLA 2 ) form a diverse family of enzymes involved in a variety of physiologic and pathologic processes. Common among all sPLA 2 is the ability to cleave the second position of phospholipids, thereby releasing fatty acid and a lysophospholipid. Several sPLA 2 have been cloned and characterized in various tissues and receptors have been identified. In the nervous system, sPLA 2 groups IB, IIA, IIE, IIF, V, and XII have been identified, and binding sites for sPLA 2 have been found. Here, we report sPLA 2 ‐IIE and sPLA 2 ‐X in rat brain as well as in neurons in primary culture. We furthermore confirm the presence of sPLA 2 ‐V in rat brain and demonstrate the presence of sPLA 2 ‐V in primary neuronal cultures. The distribution of sPLA 2 ‐IIE, V, and ‐X seems to be mainly neuronal, with the highest abundance occurring in the cerebral cortex and hippocampus. We also find that sPLA 2 ‐IIE, ‐V, and ‐X are differentially induced by kainic acid. This study supports the concept that sPLA 2 heterogeneity in brain is functionally relevant and responsive to seizures. © 2006 Wiley‐Liss, Inc.