these studies show that a fraction enriched in synaptosomes and neural membranes from the canine intestine smp contains opioid as well as alpha 2-adrenoceptors , that all three subtypes of opioid receptors seem to be present with mu-receptors predominant , and that subtypes of alpha 2-adrenoceptors appear to be present .
C0034801
opioid receptors
C0066908
mu-receptors