1. OpioidreceptorsClassificationCellularmechanismsAgonists and antagonists Flavio Guzmán, MD

2. Presentationoutline General classification Cellular actions of opioid receptors Mu receptors Delta receptors Kappa receptors Review ORL-1 receptors

3. Classification: opioidreceptors

4. Opioidreceptors are 7 transmembranereceptors 3 2 1 N- terminus 4 3 1 2 5 6 7 3 1 2 C- terminus

5. Before opioid receptor activation Presynaptic neuron

6. After opiod receptor activation Morphine

7. Glutamate, Ach, NE, 5-HT, substance P

8. Mu opioid agonists Exogenous drug Endogenous peptide

9. Mu antagonist

12. Delta receptors Exogenous drug Endogenous peptide

13. Delta antagonist

16. Kappa receptor agonists Exogenous drug Endogenous peptides

17. Kappa antagonist

20. Receptor review Endogenous peptides Antagonists Exogenous drug agonists

21. ORL1 receptor Opioid-like-subtype-1 receptor Also known as: nociceptin receptor (NOP) Orphanin FQ receptor

22. ORL1 receptor- Natural ligand Nociceptin or orphanin FQ only acts at the ORL1 receptor.

23. ORL1 receptor Effects upon activation: Central modulation of pain. Effects on locomotion, stress, anxiety, feeding, learning and memory, reward/addiction and urogenital activity.

24. References and further reading Katzung, B. Basic and Clinical Pharmacology. 11th ed. McGraw Hill Medical, 2009 Koneru A, Sreemantula S, Rizwan. Endogenous Opioids: Their Physiological Role and Receptors. Global J. Pharmacol., 3 (3): 149-153, 2009 McDonald J, Lambert DJ. Opioid Receptors. Continuing Education in Anaesthesia, Critical Care & Pain 2005 5:1 Trescot A, Sukdeb D. Opioid Pharmacology. Pain Physician 2008; 11:S133-S153