we studied ventilation and ventilatory pattern in adult unanesthetized dogs after intracisternal administration of morphiceptin analogue ( ma ) ( tyr-pro-nmephe-d-pro-nh2 ) and morphine sulfate ( ms ) which are mu-receptor opioid agonists and after d-ala-d-leu-enkephalin ( dadle ) , a preferential delta-receptor opioid agonist .
C0014294
leu-enkephalin
C0079286
dadle