Specific protection of the binding sites of D-Ala2-D-Leu5-enkephalin (delta-receptors) and dihydromorphine (mu-receptors).
Phenoxybenzamine causes a long-lasting inactivation of the opiate receptors of the mu- and delta-type in homogenates of guinea-pig brain. The effect is selectively prevented when, before exposure to phenoxybenzamine, the homogenate is pre-incubated with ligands of high affinity for either of the two binding sites, i.e. dihydromorphine for the mu-receptor and Tyr-D-Ala-Gly-Phe-D-Leu for the delta-receptor. In contrast, Tyr-D-Ala-Gly-Phe-L-Leu amide, which has high affinities for both binding sites, protects both receptor sites.
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D004090:Dihydromorphine / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D006168:Guinea Pigs; D007700:Kinetics; D008024:Ligands; D009022:Morphine Derivatives / Q000378:metabolism*; D011957:Receptors, Opioid / Q000302:isolation & purification / Q000378:metabolism*; D013329:Structure-Activity Relationship
D004723:Endorphins; D004745:Enkephalins; D008024:Ligands; D009022:Morphine Derivatives; D011957:Receptors, Opioid; D004090:Dihydromorphine