Degradation of substance P by neurones and glial cells.
Neuronal and astroblast-rich cultures from rat brain degrade exogenously added substance P. The rate of degradation is decreased by diisopropylfluorophosphate, phosphoramidon and bacitracin, but not by N-ethylmaleimide or bestatin. When diisopropylfluorophosphate, phosphoramidon and bacitracin are simultaneously present in the culture medium, the degradation of substance P is completely inhibited. These results indicate that the hydrolysis of substance P by intact cells is catalyzed by the post-proline dipeptidylaminopeptidase (EC 3.4.14.5), the thermolysin-like metallopeptidase ("enkephalinase", EC 3.4.24.11) and a yet uncharacterized bacitracin-sensitive activity. While the thermolysin-like metallopeptidase is mainly associated with glial cells, the specific activity of the other enzymes is five times higher in the neuronal culture.
D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002478:Cells, Cultured; D007700:Kinetics; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D013373:Substance P / Q000378:metabolism*; D014316:Tritium
D014316:Tritium; D013373:Substance P