Nociception, enkephalin content and dipeptidyl carboxypeptidase activity in brain of mice treated with exopeptidase inhibitors.
Thiorphan (60 micrograms intracerebrally) increased the met5-enkephalin content of mouse striatum by 30% in 30 min. This increase was no longer evident at 1 hr. If the dipeptidyl carboxypeptidase, inhibited by thiorphan, were located extraneuronally as suggested by De La Baume, Patey and Schwartz (1981), the met5-enkephalin accumulation represents the rate at which the pentapeptide is released extraneuronally. The increase in met5-enkephalin content was accompanied by an inhibition, greater than 80%, of the dipeptidyl carboxypeptidase that degrades striatal met5-enkephalin. Such an inhibition lasted longer then 2 hr. Thiorphan, given to mice intracerebrally, prolonged the latency time to jump off a 54 degree plate. The effects of thiorphan on brain met5-enkephalin content and hot plate latencies were significantly potentiated by bestatin, which inhibits aminopeptidase B and leucine aminopeptidase.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D004744:Enkephalin, Methionine / Q000378:metabolism; D004745:Enkephalins / Q000378:metabolism*; D020689:Exopeptidases; D005260:Female; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D015260:Neprilysin; D009619:Nociceptors / Q000187:drug effects*; D011480:Protease Inhibitors; D015244:Thiorphan; D008625:Tiopronin / Q000031:analogs & derivatives / Q000494:pharmacology
D004745:Enkephalins; D011480:Protease Inhibitors; D004744:Enkephalin, Methionine; D015244:Thiorphan; D008625:Tiopronin; D010450:Endopeptidases; D020689:Exopeptidases; C020071:dipeptidyl carboxypeptidase; D015260:Neprilysin; D007930:Leucine; C012211:ubenimex