with regard to this altered function of the G118 allele. Another consequence of MOPR activation, Ca2+ inhibition, was investigated using rat sympathetic superior ganglion (SCG) neurons expressing either the A118 or G118 variant of the hMOPR. In these studies, the potencies of both DAMGO- and morphine-mediated Ca2+ current inhibition (but not morphine-6-glucuronide or endomorphin I) were increased in SCG neurons expressing the G118 variant (Margas et al., 2007), again suggesting enhanced response for some but not all opioid compounds.
