Dissociated effects of inhibitors of enkephalin-metabolising peptidase or naloxone on various nociceptive responses

摘要: Abstract The antinociceptive effects of Thiorphan, an ‘enkephalinase’ inhibitor, or bestatin, aminopeptidase inhibitor as well their association and the pronociceptive naloxone, opiate receptor antagonist, were evaluated iin various analgesic tests in mice. These could be classified into two groups: (i) those which peptidase inhibitors display naloxone-sensitive activity, particularly when administered together, naloxone displays activity (vocalisation, hot-plate jump, writhing), (ii) are ineffective (tail withdrawal, licking, tail-flick). In contrast to above, either morphine [Met 5 ]enkephalin subthreshold dosage together with displayed groups tests. threshold dosages lowest first group. dissociated opposite per se might reflect a variable participation endogenous enkephalins (or other opioid peptides) control nociceptive responses.