in contrast to the insensitivity of the lactating rat to morphine stimulation of prolactin release , the intraventricular administration of two other opiate receptor agonists , beta-endorphin ( 10 or 20 micrograms ) and [ d-ala-d-leu ] enkephalin ( dadle ; 5 or 10 micrograms ) , produced significant increases in circulating levels of this hormone .
C0014294
leu ] enkephalin
C0079286
dadle