SELECTIVE INTERACTION OF HOMOPHTALAZINE DERIVATIVES WITH MORPHINE

Homophtalazines show specific binding sites in the nigrostriatal syste m and to find their target of action the interactions between these de rivatives, nerisopam and girisopam, and chlorpromazine, chlordiazepoxi de and morphine were assessed. The compounds did not influence the chl orpromazine induced decrease in motility and catalepsy, nor did they a lter the antiaggressive and anticonvulsive action of chlordiazepoxide. However, nerisopam and girisopam augmented the agonist potency of mor phine to induce catalepsy or analgesia; they also altered the opioid a ntagonist potency of naloxone. The naloxone-induced decrease in sucros e consumption in drinking water was augmented by nerisopam and girisop arn. It is suggested that a possible target of action of homophtalazin es is the opioid signal transduction. (C) 1997 Elsevier Science B.V.