title: Demonstration of the crucial role of the phenylalanine moiety in enkephalin analogues for differential recognition of the mu- and delta-receptors.
mesh_terms: D000818:Animals; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects; D010649:Phenylalanine / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects*; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D004723:Endorphins; D004745:Enkephalins; D011957:Receptors, Opioid; D010649:Phenylalanine