Clozapine inhibition of metenkephalin binding to synaptosome-enriched fractions of rat whole brain and hippocampus.

Clozapine has been found to inhibit the binding of [3H]met-enkephalin to synaptosome-enriched fractions prepared from rat whole brain and hippocampus in a Tris-buffered media without added ions. The IC50 value for hippocampus is 28.5 microM. The inhibition constant for whole brain (41.0 microM) was found to be slightly larger than the corresponding value for chlorpromazine, which was measured under similar experimental conditions.