Cannabinoid receptors are part of the largest known family of receptors, the G protein-coupled receptors, which - in this case - has a distinctive pattern in which the receptor molecule spans the cell membrane seven times over. The CB1 receptor is one of the most numerous G protein-coupled receptors in the nervous system.
Cannabinoid receptors were originally discovered as being sensitive to Δ9-tetrahydrocannabinol (Δ9-THC, commonly called THC), which is the primary psychoactive cannabinoid found in cannabis. The discovery of anandamide came from research into CB1 and CB2, as it was inevitable that a naturally occurring (endogenous) chemical would be found to affect these receptors.
Anandamide has been shown to be involved in working memory. Studies are under way to explore what role anandamide plays in human behavior, such as eating and sleep patterns, and pain relief.
Anandamide is also important for implantation of the early stage embryo in its blastocyst form into the uterus. Therefore cannabinoids such as Δ9-THC might interfere with the earliest stages of human pregnancy.
Anandamide also is important in the regulation of feeding behavior, and the neural generation of motivation and pleasure. Both anandamide and exogenous cannabinoids like THC enhance food intake in animals and humans, an effect that is sometimes called the 'marijuana munchies.' In addition, anandamide injected directly into the forebrain reward-related brain structure nucleus accumbens enhances the pleasurable responses of rats to a rewarding sucrose taste, and enhances food intake as well.
Moreover, anandamide is thought to be an endogenous ligand for vanilloid receptors (which are involved in the transduction of acute and inflammatory pain signals), activating the receptor in a PKC-dependent (protein kinase C-dependent) manner.
Anandamide occurs in minute quantities in sea urchin roe. Anandamide was reported to be present in chocolate in small quantitities that were not assumed to have pharmacological or psychoactive effects. However, a later study failed to repeat these findings and did not detect anandamide in chocolate.
The human body synthesizes anandamide from N-arachidonoyl phosphatidylethanolamine, which is itself made by transferring arachidonic acid from phosphatidylcholine (PC) to the free amine of phosphatidylethanolamine (PE). Endogenous anandamide is present at very low levels and has a very short half-life due to the action of the enzyme fatty acid amide hydrolase which breaks it down into free arachidonic acid and ethanolamine. Studies of piglets show that dietary levels of AA and other essential fatty acids affect the levels of anandamide and other endocannabinoids in the brain.
High fat diet feeding in mice increase levels of Anandamide in the liver and increase lipogenesis. This indicates that Anandamide plays a role in the development of obesity, at least in rodents.
A study lead in 1998 shows that anandamide inhibits human breast cancer cell proliferation.
Binding mode prediction of conformationally restricted anandamide analogs within the CB.sub.1 receptor.(Research article)
Feb 26, 2008; Authors: Lea W Padgett [1,2]; Allyn C Howlett [1,3]; Joong-Youn Shim (corresponding author) BackgroundCB1 and CB2 cannabinoid...