Characterization of seizure-induced cysteinyl-leukotriene formation in brain tissue of convulsion-prone gerbils.

Tonic-clonic seizures elicited in convulsion-prone gerbils resulted in a large increase in immunoreactive prostaglandin (PG) F2 alpha and in a smaller increase in immunoreactive leukotriene (LT) C4-like material in brain tissue. Brain tissue contents of both eicosanoids were found to reach a maximum at 6 min after the onset of seizures and were still elevated at 54 min after the beginning of convulsions. By reversed phase HPLC the immunoreactive LTC4-like material was identified as LTC4 and LTD4 at 6 min after the onset of convulsions, whereas at 54 min after the onset, transformation of LTD4 to LTE4 could be detected as well. In gerbils showing only weak seizure activity a small increase in PGF2 alpha but no increase in immunoreactive LTC4-like material could be detected at 6 min after the onset of convulsions. Pretreatment with indomethacin abolished the formation of PGF2 alpha but significantly enhanced the biosynthesis of immunoreactive LTC4-like material at 18 min after the beginning of seizures. The results demonstrate formation of cysteinyl-LT following tonic-clonic convulsions in spontaneously convulsing gerbils which could be enhanced by inhibition of the cyclooxygenase pathway of arachidonic acid metabolism. Since cysteinyl-LT have potent biological actions in various organs this finding warrants further investigations on the potential role of cysteinyl-LT in the CNS.