METABOLIC PROFILE OF OPIOID-PEPTIDES DIFFERS IN THE HIPPOCAMPUS AND STRIATUM OF SEIZURE-SUSCEPTIBLE E1 MICE

We previously suggested that a deficit of anticonvulsant endogenous me thionine enkephalin, in the cerebral cortex, septal area, hippocampus, and striatum of seizure-susceptible El mice plays a role in the patho genesis of seizures. To determine whether a hypofunction of enkephalin ergic neuron may be due to metabolic abnormalities of opioid peptides in the El mouse brain, we measured methionine enkephalin-like immunore activity (ME-LI) of 50 fractions eluted by high performance liquid chr omatography obtained from those four regions of the brain of EI and se izure-nonsusceptible ddY mice (the mother strain of El mice). We obser ved the same ME-LI patterns of 50 fractions in the cerebral cortex and septal area in El and ddY mice, whereas exhibited differing ME-LI pat terns in the hippocampus and striatum in the two stains. Different ME- LI patterns may imply the difference in the metabolic profile of opioi d peptides. Thus, an abnormal metabolism of opioid peptides in the hip pocampus-and striatum of the EI mouse may be involved in the pathogene sis of seizures.