<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Fichna,J.</style></author><author><style face="normal" font="default" size="100%">Piestrzeniewicz,M.</style></author><author><style face="normal" font="default" size="100%">Gach,K.</style></author><author><style face="normal" font="default" size="100%">J Poels</style></author><author><style face="normal" font="default" size="100%">Burgeon,E.</style></author><author><style face="normal" font="default" size="100%">J. Vanden Broeck</style></author><author><style face="normal" font="default" size="100%">A.E. Janecka</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">[D-1-Nal4]endomorphin-2 is a potent micro-opioid receptor antagonist in the aequorin luminescence-based calcium assay4398</style></title><secondary-title><style face="normal" font="default" size="100%">Life Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">0</style></keyword><keyword><style  face="normal" font="default" size="100%">a</style></keyword><keyword><style  face="normal" font="default" size="100%">Aequorin</style></keyword><keyword><style  face="normal" font="default" size="100%">agonists</style></keyword><keyword><style  face="normal" font="default" size="100%">analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">antagonists &amp; inhibitors</style></keyword><keyword><style  face="normal" font="default" size="100%">article</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological Assay</style></keyword><keyword><style  face="normal" font="default" size="100%">Calcium</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Line</style></keyword><keyword><style  face="normal" font="default" size="100%">Change</style></keyword><keyword><style  face="normal" font="default" size="100%">Changes</style></keyword><keyword><style  face="normal" font="default" size="100%">chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Cho Cells</style></keyword><keyword><style  face="normal" font="default" size="100%">Cricetinae</style></keyword><keyword><style  face="normal" font="default" size="100%">data</style></keyword><keyword><style  face="normal" font="default" size="100%">Drug Evaluation,Preclinical</style></keyword><keyword><style  face="normal" font="default" size="100%">Functional</style></keyword><keyword><style  face="normal" font="default" size="100%">im</style></keyword><keyword><style  face="normal" font="default" size="100%">in vivo</style></keyword><keyword><style  face="normal" font="default" size="100%">IS</style></keyword><keyword><style  face="normal" font="default" size="100%">journal</style></keyword><keyword><style  face="normal" font="default" size="100%">Laboratories</style></keyword><keyword><style  face="normal" font="default" size="100%">LEVEL</style></keyword><keyword><style  face="normal" font="default" size="100%">levels</style></keyword><keyword><style  face="normal" font="default" size="100%">Luminescent Measurements</style></keyword><keyword><style  face="normal" font="default" size="100%">medical</style></keyword><keyword><style  face="normal" font="default" size="100%">methods</style></keyword><keyword><style  face="normal" font="default" size="100%">mice</style></keyword><keyword><style  face="normal" font="default" size="100%">observed</style></keyword><keyword><style  face="normal" font="default" size="100%">Oligopeptides</style></keyword><keyword><style  face="normal" font="default" size="100%">ON</style></keyword><keyword><style  face="normal" font="default" size="100%">pharmacology</style></keyword><keyword><style  face="normal" font="default" size="100%">Print</style></keyword><keyword><style  face="normal" font="default" size="100%">protein</style></keyword><keyword><style  face="normal" font="default" size="100%">Receptor</style></keyword><keyword><style  face="normal" font="default" size="100%">receptors</style></keyword><keyword><style  face="normal" font="default" size="100%">Receptors,Opioid</style></keyword><keyword><style  face="normal" font="default" size="100%">recombinant</style></keyword><keyword><style  face="normal" font="default" size="100%">relative</style></keyword><keyword><style  face="normal" font="default" size="100%">Research</style></keyword><keyword><style  face="normal" font="default" size="100%">Research Support</style></keyword><keyword><style  face="normal" font="default" size="100%">result</style></keyword><keyword><style  face="normal" font="default" size="100%">results</style></keyword><keyword><style  face="normal" font="default" size="100%">SB - IM</style></keyword><keyword><style  face="normal" font="default" size="100%">series</style></keyword><keyword><style  face="normal" font="default" size="100%">structure</style></keyword><keyword><style  face="normal" font="default" size="100%">study</style></keyword><keyword><style  face="normal" font="default" size="100%">Test</style></keyword><keyword><style  face="normal" font="default" size="100%">Universities</style></keyword><keyword><style  face="normal" font="default" size="100%">university</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">8/8/2006</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">1099</style></number><volume><style face="normal" font="default" size="100%">79</style></volume><pages><style face="normal" font="default" size="100%">1094 - 1099</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A functional assay, based on aequorin-derived luminescence triggered by receptor-mediated changes in Ca(2+) levels, was used to examine relative potency and efficacy of the micro-opioid receptor antagonists. A series of position 3- and 4-substituted endomorphin-2 (Tyr-Pro-Phe-Phe-NH(2)) analogues containing D-3-(1-naphthyl)-alanine (D-1-Nal) or D-3-(2-naphthyl)-alanine (D-2-Nal), which were previously shown to reverse antinociception induced by endomorphin-2 in the in vivo hot-plate test in mice, was tested in the aequorin luminescence-based calcium assay to examine their micro-opioid antagonist potency in vitro. A recombinant mammalian cell line expressing the micro-opioid receptor together with a luminescent reporter protein, apoaequorin, was used in the study. The results obtained in this functional assay indicated that analogues with D-1-Nal or D-2-Nal substitutions in position 4 of endomorphin-2 are strong micro-opioid receptor antagonists, while those substituted in position 3 are partial agonists. Exceptional antagonist potency in the calcium assay was observed for [D-1-Nal(4)]endomorphin-2. The pA(2) value for this analogue was 7.95, compared to the value of 8.68 obtained for the universal, non-selective opioid antagonist of the alkaloid structure, naloxone. The obtained results were compared with the data from the hot-plate test in mice. In that in vivo assay [D-1-Nal(4)]endomorphin-2 was also the most potent analogue of the series</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue><custom1><style face="normal" font="default" size="100%">4398</style></custom1><section><style face="normal" font="default" size="100%">1094</style></section></record></records></xml>