Spinorphin (LVVYPWT) has been isolated from the bovine spinal cord as an endogenous inhibitor of enkephalin-degrading enzymes. It has been reported that spinorphin has an antinociceptive effect, inhibitory effect on contraction of smooth muscle and anti-inflammatory effect. In the present study, the effects of leu-enkephalin and spinorphin on allodynia and mechanical and thermal nociceptions were examined in vivo using mice. Intrathecal (i.t.) administration of leu-enkephalin or spinorphin inhibited the allodynia induced by intrathecal nociceptin in a dose-dependent manner. Furthermore, spinorphin enhanced the inhibitory effect of enkephalin on allodynia induced by nociceptin. Naloxone antagonized both inhibitory effects of leu-enkephalin and spinorphin, suggesting that the endogenous opioidergic system can modulate allodynia. Intracerebroventricular (i.c.v.) administration of leu-enkephalin increased the nociceptive threshold of heat or mechanical stimulation to a mouse. Although i.c.v. administration of spinorphin had no effect on the threshold of heat or mechanical stimulation, spinorphin enhanced and prolonged the antinociceptive effect of leu-enkephalin. The enhancement of spinorphin on the antinociception produced by leu-enkephalin was reversed by pretreatment with naloxone. From these results, it is suggested that the effects of spinorphin on enkephalin-induced anti-allodynic and antinociceptive effects are due to inhibition of enkephalin-degrading enzymes.

Download full-text PDF

Source
http://dx.doi.org/10.1254/jjp.87.261DOI Listing

Publication Analysis

Top Keywords

enkephalin-degrading enzymes
12
leu-enkephalin spinorphin
12
spinorphin
11
endogenous inhibitor
8
inhibitor enkephalin-degrading
8
anti-allodynic antinociceptive
8
antinociceptive effects
8
effects leu-enkephalin
8
administration leu-enkephalin
8
allodynia induced
8

Similar Publications

Article Synopsis
  • The endogenous opioid system helps regulate pain through the release of neuropeptides, but opioid peptides like enkephalins are quickly broken down by enzymes, limiting their effectiveness.
  • A novel approach to manage pain involves developing inhibitors that prevent the breakdown of enkephalins, with previous studies identifying a promising compound that needs refinement to avoid toxic side effects.
  • The new compound improved pain relief and showed strong interaction with opioid receptors, while further research indicated it has good stability in the body and supports the continued development of these inhibitors for better pain management.
View Article and Find Full Text PDF
Article Synopsis
  • The endogenous opioid system manages pain through neuropeptides like enkephalins, but their effectiveness is limited because they are quickly broken down by enzymes.
  • An innovative solution proposed is to create drugs that inhibit these enzymes, specifically puromycin sensitive aminopeptidase (PSA), to increase the stability and concentration of enkephalins for longer-lasting pain relief.
  • New derivatives of existing compounds showed promise by maintaining PSA inhibition without causing toxicity, leading to significant pain reduction in tests, and confirming the role of opioid receptors in the analgesic effects observed.
View Article and Find Full Text PDF

Structure of puromycin-sensitive aminopeptidase and polyglutamine binding.

PLoS One

July 2023

Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, Kentucky, United States of America.

Puromycin-sensitive aminopeptidase (E.C. 3.

View Article and Find Full Text PDF

Rapid identification of lung-cancer micro-lesions is becoming increasingly important to improve the outcome of surgery by accurately defining the tumor/normal tissue margins and detecting tiny tumors, especially for patients with low lung function and early-stage cancer. The purpose of this study is to select and validate the best red fluorescent probe for rapid diagnosis of lung cancer by screening a library of 400 red fluorescent probes based on 2-methyl silicon rhodamine (2MeSiR) as the fluorescent scaffold, as well as to identify the target enzymes that activate the selected probe, and to confirm their expression in cancer cells. The selected probe, glutamine-alanine-2-methyl silicon rhodamine (QA-2MeSiR), showed 96.

View Article and Find Full Text PDF

PSA controls hepatic lipid metabolism by regulating the NRF2 signaling pathway.

J Mol Cell Biol

October 2021

Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, The Second Affiliated Hospital of Army Medical University, Chongqing, China.

The activity of proteinase is reported to correlate with the development and progression of nonalcoholic fatty liver disease (NAFLD). Puromycin-sensitive aminopeptidase (PSA/NPEPPS) is an integral nontransmembrane enzyme that functions to catalyze the cleavage of amino acids near the N-terminus of polypeptides. A previous study suggested that this enzyme acts as a regulator of neuropeptide activity; however, the metabolic function of this enzyme in the liver has not been explored.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!