Endocannabinoid System and Receptors
What Is The Endocannabinoid System?
In 1964, researchers in Israel discovered the therapeutically active substances in cannabis that have come to be called cannabinoids and isolated the most popular and possibly effective cannabinoid, THC (tetrahydrocannabinol). More than 20 years later, in 1988, researchers identified the human body’s endocannabinoid system.
Endocannabinoids are the special molecules naturally produced in the human body that are closely related to proper functioning of the immune system and nervous system and that are mimicked by the cannabinoids found in the cannabis plant. Cannabinoids contained in cannabis, referred to as phytocannabinoids, simply imitate endocannabinoids. Cannabinoids fit perfectly into specialized receptors found throughout the nervous and immune systems, serving to enhance, or improve upon, the body’s own ability to maintain homeostasis (balance) and health.
The Role of Receptors
Research since the discovery of the endocannabinoid system has led to the identification of specialized receptors in the body. Knowledge of these receptors, called CB1 and CB2, has greatly enhanced the overall knowledge of how cannabinoids synergistically interact with other cannabinoids and endocannabinoids to produce sometimes profound medical effects. An understanding of these receptors also allows for the production of synthetic cannabinoids and specialized extracts that best take advantage of the function of these receptors.
Cannabinoid receptors are present throughout the body, embedded in cell membranes, and are believed to be more numerous than any other receptor system. When cannabinoid receptors are stimulated, a variety of physiologic processes ensue. Researchers have identified two cannabinoid receptors: CB1, predominantly present in the nervous system, connective tissues, gonads, glands, and organs; and CB2, predominantly found in the immune system and its associated structures. Many tissues contain both CB1 and CB2 receptors, each linked to a different action. Researchers speculate there may be a third cannabinoid receptor waiting to be discovered.
CB1 receptors are located throughout the brain and central nervous system, as well as the kidneys, liver, lungs, digestive tract, and even the eyes. Revealingly, these receptors outnumber those for opiates by a wide margin (possibly as high as 10 to 1). The placement of CB1 receptors is also why overdoses on cannabis are impossible – because these receptors are not present in the basal regions of the brain that are responsible for vital functions, such as heart and respiratory function, overdoses due solely to cannabis use simply do not occur.
CB2 receptors are primarily found in the peripheral organs, in particular tissues associated with the immune system, including the tonsils, thymus, spleen, and bone marrow.