to examine the relative roles of mu 1- and mu 2-receptors in spinal and supraspinal analgesia , we assessed the effects of naloxonazine , naloxone , beta-funaltrexamine ( beta-fna ) , and ici-154,129 on tail-flick analgesia produced by intrathecal or intracerebroventricular injections of the highly mu-selective agonist , [ d-ala2 , me-phe4 , gly ( ol ) 5 ] enkephalin ( dago ; mu 1 and mu 2 ) , [ d-ser2 , leu5 ] enkephalin-thr6 ( dslet ; mu 1 and delta ) , and the selective delta-receptor agonist [ d-pen2 , d-pen5 ] enkephalin ( dpdpe ) in mice .
C0014298
enkephalin
C0525856
dpdpe