Biological Characteristics of the CB1 and CB2 Receptors
CB1 | CB2 | |
---|---|---|
a Adapted with permission from Sigma-RBI Handbook of Receptor Classification and Signal Transduction. | ||
Size (amino acid residues) | 472 | 360 |
Tissue expression | Brain (cerebellum, basal ganglia, cerebral cortex), liver, testes | Peripheral immune cells, sparse in brain |
Physiological function | Presynaptic heteroreceptor; inhibits neurotransmitter release | Suppress immune cell function |
Disease relevance | Pain, appetite regulation, anxiety, craving, emesis | Pain, immune system regulation, muscle spasms |
Signal transduction mechanisms | Gαi (cAMP modulation) Inhibits voltage-sensitive Ca2+ channels (N-, Q-type) Activates Kir and KA conductance | Gαi (cAMP modulation) |
Endogenous agonists (common to both CB1 and CB2) | Arachidonoyl ethanolamide (anandamide) | |
2-Arachidonoyl glycerol (2-AG) | ||
2-Arachidonoyl glyceryl ether (Nolandin ether) | ||
N-Arachidonoyl dopamine | ||
O-Arachidonoyl ethanolamine (Virodhamine) |