Opioid peptides: endorphins and enkephalins.
D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D006801:Humans; D011956:Receptors, Cell Surface / Q000378:metabolism; D011957:Receptors, Opioid / Q000378:metabolism
D004723:Endorphins; D004745:Enkephalins; D011956:Receptors, Cell Surface; D011957:Receptors, Opioid