the binding of 3h-dihydromorphine and 3h-naloxone ( mu receptors ) , 3h-d-ala2-d-leu5-enkephalin ( delta receptors ) , and 3h-ethylketocyclazocine ( kappa receptors ) to opiate receptors in the mouse brain homogenate was also unaffected by both the peptides over a large concentration range .
C0066908
mu receptors
C0034801
opiate