in an attempt to ascertain whether opiate receptors and brain enkephalins or endorphins are involved in pentobarbital anesthesia and toxicity , the effects of 1 ) two pure narcotic antagonists , naloxone and naltrexone , 2 ) morphine sulfate , 3 ) d-phenylalanine , an inhibitor of carboxypeptidase a , and 4 ) d-leucine , an inhibitor of leucineaminopeptidase , in combination with d-phenylalanine , were studied in mice .
C0027358
naloxone
C0027360
naltrexone