LONG-TERM PHARMACOLOGICAL KINDLING INCREASES IN-VITRO RELEASE OF IR-MET AND IR-LEU-ENKEPHALIN FROM AMYGDALA

Met-enkephalin release is increased from amygdala and striatum 1 and 1 5 days after pharmacological kindling with pentylenetetrazol, followin g potassium-induced depolarization in vitro via a Ca2+ dependent mecha nism. Leu-enkephalin release was only enhanced in amygdala and striatu m 1 day after the last seizure. IR-Met-enkephalin amygdala tissue cont ent enhanced 1 and 15 days after seizure. In striatum, we found an IR- Met-enkephalin decrease 35 days after the last stimulus. IR-Leu-enkeph alin amygdala tissue content enhanced 1 day after the last seizure, an d no significant increases were found in striatum 1, 15 and 35 days af ter the last seizure. In this paper, we show that opioid peptides rele ase is differentially enhanced in rat brain for several days after the last seizure, thus suggesting that opioid peptides may have a protect ive action against seizure activity. (C) 1998 Elsevier Science Inc. Al l rights reserved.