Anandamide Anandamide is also known as N-arachidonoylethanolamine or AEA, and is an endogenous analogue of tetrahydrocannabinol, or THC. Anandamide has an effect on both the CB1 and CB2 receptors; with the CB1 receptors more affected in the central nervous system and the CB2 receptors more affected in the periphery.
Chemical properties of anandamide
Anandamide belongs to a class of bioactive lipids known as fatty acid amides (FAAs). However, anandamide is also said to belong to the class of eicosanoids, a group of lipids derived from arachidonic acid and other essential fatty acids (EFAs). Anandamide is a large molecule made up of oxygen, hydrogen, nitrogen and carbon atoms, with the molecular formula C22H37NO2 and a molar mass of 347.53 g/mol.
As well as a hydroxyl group (an oxygen atom joined by covalent bond to a hydrogen atom), the anandamide molecule consists of a single nitrogen-hydrogen pairing and a hydrocarbon tail. The hydrocarbon tail of a molecule is hydrophobic but lipophilic, meaning that it is soluble in fat but does not dissolve in water. This hydrophobic property is common to all lipids and all known cannabinoids, which are lipidic in nature.
How the body produces anandamide
Anandamide is produced in the cell membranes and tissues of the body. In order to synthesise the molecule, the precursor molecule N-arachidonoyl phosphatidylethanolamine (NAPE) is needed. NAPE itself is made by the bonding of arachidonic acid (an omega-6 EFA) and a free amine through the action of the enzyme N-acyltransferase. Variations in dietary consumption of arachidonic acid can alter the levels of anandamide present in the brain.
Anandamide is degraded by the fatty acid amide hydrolase (FAAH) enzyme, which converts the molecule back into arachidonic acid and ethanolamine, another amine. Due to its comparatively short half-life and high fat solubility, anandamide is considered a “fragile” molecule, and its effects are short-lived—unlike THC, which can remain in the fatty tissues for several weeks.
The effects of anandamide
Anandamide plays an important role in the regulation of appetite, pleasure and reward, and elevated levels may increase the pleasure experienced on consumption of food. Anandamide has been found in chocolate, and is thought to be partly responsible for the intense enjoyment experienced while eating it. Anandamide may also be partly responsible for pain regulation and sleep patterns.
Anandamide also has an important and as yet poorly understood role in hormonal balance and the reproductive system. During ovulation, plasma levels of anandamide are at their highest, as are levels of the sex hormones gonadotrophin and estradiol (a type of estrogen). However, it is not clear exactly what relationship these substances have with each other. Anandamide is also vital in ensuring the healthy implantation of the young embryo into the epithelium (wall) of the uterus in early pregnancy.