the binding properties of mu and delta opioid receptors were investigated in several areas of human brain by using [ 3h ] tyr-d-ala-gly- ( me ) phe-gly-ol and [ 3h ] tyr-d-thr-gly-phe-leu-thr as respective selective ligands , while the totality of opioid receptors was measured by using [ 3h ] etorphine as a non-selective agonist .
C0140057
delta opioid receptors
C0034801
opioid receptors