the purpose of these investigations was to determine 1 ) whether peripherally located mu , delta and kappa opioid receptors can inhibit the rate of gastrointestinal transit and , if so , 2 ) do peripheral opioid receptors mediate the constipation caused by systemic morphine ? and 3 ) whether constipation can be separated from analgesia on the basis of different sites of action .
C0064239
kappa opioid receptors
C0034801
opioid receptors