Open AccessThe Role of Bestatin-Sensitive Aminopeptidase, Angiotensin Converting Enzyme and Thiorphan-Sensitive "Enkephalinase" in the Potency of Enkephalins in the Guinea-Pig Ileum
Author(s) -
Kazuko Aoki,
Midori Kajiwara,
Tetsuo Oka
Publication year - 1984
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.36.59
Subject(s) - enkephalinase , thiorphan , enkephalin , aminopeptidase , phosphoramidon , chemistry , endopeptidase , angiotensin iii , bradykinin , opioid peptide , neprilysin , guinea pig , enzyme , myenteric plexus , biochemistry , ileum , receptor , angiotensin converting enzyme , endocrinology , angiotensin ii , medicine , biology , opioid , angiotensin receptor , amino acid , leucine , immunohistochemistry , blood pressure
The role of each enkephalin-hydrolyzing peptidase in the inhibitory potency of exogenously added enkephalins in the myenteric plexus-longitudinal muscle preparation of guinea-pig ileum was studied by using the relatively specific inhibitor of each enzyme. Results showed that three distinct enzymes, bestatin-sensitive aminopeptidase(s), angiotensin converting enzyme, and thiorphan-sensitive "enkephalinase", played a critical role in the inactivation of enkephalins. Additionally, these enzymes are likely to be located close to opioid receptors, since they produce a significant concentration difference of enkephalin between the surrounding organ bath and the vicinity of opioid receptors. In contrast to these three enzymes, both L-tyrosyl-L-tyrosine-sensitive dipeptidyl aminopeptidase and D-phenylalanine-sensitive carboxypeptidase are indicated not to be involved significantly in the degradation of exogenously added enkephalins in the guinea-pig ileum.