Blockade of analgesic effects following systemic administration of N-methyl-kyotorphin, NMYR and arginine in mice deficient of preproenkephalin or proopiomelanocortin gene

Add time:08/14/2019    Source:sciencedirect.com

Kyotorphin is a unique biologically active neuropeptide (l-tyrosine-l-arginine), which is reported to have opioid-like analgesic actions through a release of Met-enkephalin from the brain slices. N-methyl-l-tyrosine-l-arginine (NMYR), an enzymatically stable mimetic of kyotorphin, successfully caused potent analgesic effects in thermal and mechanical nociception tests in mice when it was given through systemic routes. NMYR analgesia was abolished in μ-opioid receptor-deficient (MOP-KO) mice, and by intracerebroventricular (i.c.v.) injection of naloxone and of N-methyl l-leucine-l-arginine (NMLR), a kyotorphin receptor antagonist. In the Ca2+-mobilization assay using CHO cells expressing Gαqi5 and hMOPr or hDOPr, however, the addition of kyotorphin neither activated MOPr-mechanisms, nor affected the concentration-dependent activation of DAMGO- or Met-Enkephalin-induced MOPr activation, and Met-enkephalin-induced DOPr activation. NMYR-analgesia was significantly attenuated in preproenkephalin (PENK)- or proopioimelanocortin (POMC)-KO mice. The systemic administration of arginine, which is reported to elevate the level of endogenous kyotorphin selectively in midbrain and medulla oblongata, pain-related brain regions, caused significant analgesia, and the analgesia was reversed by i.c.v. injection of NMLR or naloxone. In addition, PENK- and POMC-KO mice also attenuated the arginine-induced analgesia. All these findings suggest that NMYR and arginine activate brain kyotorphin receptor in direct and indirect manner, respectively and both compounds indirectly cause the opioid-like analgesia through the action of endogenous opioid peptides.

We also recommend Trading Suppliers and Manufacturers of enkephalin, Met(2)-ProNH2(5)(N(1.5)-glucopyranosyl) (cas 113282-21-6). Pls Click Website Link as below: cas 113282-21-6 suppliers

Prev:Elevated serum [Met5]-enkephalin levels correlate with improved clinical and behavioral outcomes in experimental autoimmune encephalomyelitis
Next:Perinatal ethanol exposure alters met-enkephalin levels of male and female rats)