Is substance P released from slices of the rat spinal cord inactivated by peptidase(s) distinct from both 'enkephalinase' and 'angiotensin-converting enzyme'?
Studies on the effects of peptidase inhibitors on substance P-like immunoreactive material (SPLI) released by K(+)-induced depolarization from slices of the rat spinal cord showed that bacitracin was the most potent agent to protect SPLI from degradation. Captopril and thiorphan which inhibit, respectively, angiotensin I converting enzyme and endopeptidase-24.11 also protected SPLI from degradation. However other inhibitors of these two enzymes, kelatorphan for endopeptidase-24.11 and enalaprilat for angiotensin I converting enzyme were essentially inactive, indicating that both enzymes are probably not involved in the degradation of endogenous substance P. Instead, the non-additive protecting effect of bacitracin, captopril and thiorphan might be due to the blockade of some 'bacitracin-sensitive enzyme' playing a key role in the catabolism of SP within the rat spinal cord.
Mauborgne
A
A
INSERM U 288, Faculté de Médecine Pitié-Salpêtrière, Paris, France.
Bourgoin
S
S
Benoliel
J J
JJ
Hamon
M
M
Cesselin
F
F
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D008297:Male; D015260:Neprilysin / Q000037:antagonists & inhibitors / Q000502:physiology*; D010447:Peptide Hydrolases / Q000494:pharmacology / Q000502:physiology*; D007703:Peptidyl-Dipeptidase A / Q000502:physiology*; D011480:Protease Inhibitors / Q000494:pharmacology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism*
D000806:Angiotensin-Converting Enzyme Inhibitors; D011480:Protease Inhibitors; D013373:Substance P; D010447:Peptide Hydrolases; D007703:Peptidyl-Dipeptidase A; D015260:Neprilysin