Differential efficacies of kappa agonists to induce homologous desensitization of human kappa opioid receptor.
The efficacies of different K agonists to activate K opioid receptor (kappaOR) and to induce acute homologous desensitization of kappaOR-mediated extracellular acidification response (ECAR) have been investigated using microphysiometry in Chinese hamster ovary (CHO) cells stably expressing kappaOR. Although efficacy of dynorphin A (DA) to stimulate kappaOR-mediated ECAR was comparable to that of U69593, DA displayed a significant higher efficacy to induce desensitization of kappaOR. Moreover, the half life for the recovery of kappaOR responsiveness after DA prechallenge was four times longer than those observed after U69593 or etorphine pretreatment. In contrast, the efficacy of DA to stimulate and desensitize mu opioid receptors (muOR) stably expressed in CHO cells were comparable to those of other mu agonists.
Ling
K
K
Shanghai Institute of Cell Biology, Chinese Academy of Sciences, PR China.
Ma
L
L
Pei
G
G
D000818:Animals; D044482:Benzeneacetamides; D016466:CHO Cells; D006224:Cricetinae; D004399:Dynorphins / Q000494:pharmacology; D005048:Etorphine / Q000494:pharmacology; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011759:Pyrrolidines / Q000494:pharmacology; D017473:Receptors, Opioid, kappa / Q000819:agonists* / Q000187:drug effects / Q000378:metabolism*
D044482:Benzeneacetamides; D011759:Pyrrolidines; D017473:Receptors, Opioid, kappa; D005048:Etorphine; D004399:Dynorphins; C045444:U 69593