Endocannabinoids need a place to do their work. So the body has specialized chemical receptors which play critical roles in our health. When endocannabinoids or phytocannabinoids interact with these receptor sites, they’re letting the body know when it’s under attack from disease or otherwise out of balance.
In the 1990s, researchers identified two cannabinoid receptors which they named CB1 and CB2. CB1 receptors are concentrated in the brain and nerves, while CB2 receptors are spread throughout the body and found on immune cells. In particular, CB1 receptors have been found to control the release of neurotransmitters, which means they help tell muscles, glands and organs what to do and when to do it. CB2 receptors are involved with the release of cytokines, which are cell-signaling proteins that allow the immune system to communicate with itself and self-regulate.
The ECS comprises more than just endocannabinoids and receptors. A multitude of enzymes, lipids, and proteins get involved too. They modulate how endocannabinoids are synthesized and degraded, and influence receptor responses. If endocannabinoids are not synthesized quickly enough — or if they’re not degraded once they’ve served their purposes at receptor sites — the ECS will not communicate harmoniously. At that point, our body's major systems (e.g., digestive, nervous, muscular, endocrine) may struggle to communicate with one another and maintain balance. And foreign phytocannabinoids interact with our ECS as well.
6 - Howlett, A. et al. International Union of Pharmacology. XXVII. Classification of cannabinoid receptors. 2002.
7 - Pertwee, R. Pharmacological actions of cannabinoids. 2005.