Pain regulation of endokinin A/B or endokinin C/D on chimeric peptide MCRT in mice.
Can J Physiol Pharmacol
; 94(9): 955-60, 2016 Sep.
Article
in En
| MEDLINE
| ID: mdl-27285300
ABSTRACT
The present study focused on the interactive pain regulation of endokinin A/B (EKA/B, the common C-terminal decapeptide in EKA and EKB) or endokinin C/D (EKC/D, the common C-terminal duodecapeptide in EKC and EKD) on chimeric peptide MCRT (YPFPFRTic-NH2, based on YPFP-NH2 and PFRTic-NH2) at the supraspinal level in mice. Results demonstrated that the co-injection of nanomolar EKA/B and MCRT showed moderate regulation, whereas 30 pmol EKA/B had no effect on MCRT. The combination of EKC/D and MCRT produced enhanced antinociception, which was nearly equal to the sum of the mathematical values of single EKC/D and MCRT. Mechanism studies revealed that pre-injected naloxone attenuated the combination significantly compared with the equivalent analgesic effects of EKC/D alone, suggesting that EKC/D and MCRT might act on two totally independent pathways. Moreover, based on the above results and previous reports, we made two reasonable hypotheses to explain the cocktail-induced analgesia, which may potentially pave the way to explore the respective regulatory mechanisms of EKA/B, EKC/D, and MCRT and to better understand the complicated pain regulation of NK1 and µ opioid receptors, as follows (1) MCRT and endomorphin-1 possibly activated different µ subtypes; and (2) picomolar EKA/B might motivate the endogenous NPFF system after NK1 activation.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptide Fragments
/
Protein Precursors
/
Pain Measurement
/
Endorphins
/
Tachykinins
Limits:
Animals
Language:
En
Journal:
Can J Physiol Pharmacol
Year:
2016
Document type:
Article
Affiliation country:
China