Is Metaphit a phencyclidine antagonist? Studies with ketamine, phencyclidine and N-methylaspartate.

The dissociative anaesthetics, phencyclidine and ketamine, block excitation of central neurones by N-methylaspartate. Using the technique of microelectrophoresis on rat spinal neurones in vivo Metaphit, a phencyclidine receptor acylating agent, was tested to see whether it would antagonise this effect of dissociative anaesthetics. The predominant effect of Metaphit was, however, to reduce N-methylaspartate induced excitation. It is concluded that Metaphit has mixed agonist/antagonist effects at the phencyclidine receptor.