The porcine μ opioid receptor (pMOR), was cloned from cerebral cortex RNA using PCR methodologies. Porcine MOR is 96% identical with human MOR in amino acid sequence. An RT-PCR survey for pMOR mRNA indicated that pMOR is widely distributed in the gut, and is present in thymus and Peyer's patches but absent in other immune tissues and in isolated immune cells. Based on these findings, it appears that opioids do not exert an immunosuppressive effect through direct interaction with the μ-opioid receptor on immune cells. In certain tissues, however, opioids may modulate immune function indirectly through neuronal MOR.
Bibliographical noteFunding Information:
This research was supported by NIDA grants DA-10200 and DA-08010 awarded to DRB and MPM, respectively. MSP was supported by the Training in Psychoneuroimmunology and Substance Abuse grant DA-07239 and MAO was supported by the Neuroscience Training in Drug Abuse Research grant DA-07234. The authors gratefully acknowledge Michael Zilliox for technical assistance and Christopher Nelsen for assistance with computer analysis.
- Mu type
- Opioid receptor