From Wikipedia, the free encyclopedia Cannabinoid Receptors

Before the 1980s, it was often speculated that cannabinoids produced their effects through nonspecific interaction with cell membranes, instead of interacting with specific recptors. The discovery of the first cannabinoid receptors in the 1980s helped to resolve this debate. These receptors are common in animals, and have been found in mammals, birds, fish, and reptiles. There are currently two known types of cannabinoid receptors, CB1 and CB2.

Cannabinoid receptors function like doors on cells that open to let in certain compounds that activate the cells."These receptors are on cells only in certain areas of the brain--including those associated with pain and pleasure."

There are over sixty known herbal cannabinoids.  Cannabinoids can be administered by smoking, vaporizing, oral ingestion, transdermal patch, intravenous injection, sublingual absorption, or rectal suppository. THC is made from the plant "Cannabis Sativa"or Marijuana and it works on "Cannabinoid Receptors" which are found on neurons in many places in our brain.   (Read more)    http://en.wikipedia.org/wiki/Cannabinoids

The Therapeutic Potential of Drugs That Target Cannabinoid Receptors or Modulate the Tissue Levels or Actions of Endocannabinoids Roger G. Pertwee  School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland

Parkinson's Disease

Results from other investigations have raised the possibility that symptoms of Parkinson's disease could be alleviated by CB₁ receptor antagonists. Thus there are 2 reports from the same laboratory that the akinesia, sensorimotor orientation, and asymmetric motor behavior exhibited by rats with 6-hydroxydopamine-induced unilateral nigral lesions can be significantly attenuated by SR141716A or AM251 when these are given either systemically or unilaterally into the striatum or globus pallidus on the lesioned side of the brain. An additional finding, that inhibitory effects of systemic SR141716A or AM251 on amphetamine-induced asymmetric motor behavior could be prevented by AM404, was taken as evidence for the presence of a CB₁₁ That CB₁ receptor antagonists could be used for the management of Parkinson's disease has also been proposed by Lastres-Becker et al. This suggestion was prompted by results they obtained in experiments with tissue both from parkinsonian patients and from marmosets lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). More specifically, they found that CB₁ receptors in parkinsonian and MPTP-lesioned basal ganglia bind more [³H]CP55940 and exhibit greater coupling efficiency than control tissue and that these changes were less marked in the basal ganglia of MPTP-treated animals that had been exposed to L-DOPA. It is noteworthy, however, that Meschler et al have reported that SR141716A does not alleviate motor deficits induced by MPTP in cynomolgus monkeys. Receptor-mediated modulation of nigrostriatal dopaminergic tone in the lesioned animals and also suggests that these antagonists were acting to reduce this tone. SR141716A and AM251 were most effective when given to rats exhibiting particularly severe behavioral signs of nigral degeneration, suggesting that cannabinoid CB receptor antagonists might be useful for treating advanced stages of Parkinson's disease in humans.

Clearly no firm conclusions can yet be drawn about the role of the endocannabinoid system in Parkinson's disease or about the extent to which modulation of this system with drugs could alleviate undesirable symptoms associated either with the disease itself or with the established anti-parkinsonian drug, L-DOPA.    (Read more) http://www.aapsj.org/view.asp?art=aapsj070364

RECEPTORS IN THE BRAIN

Marijuana and the Human Brain
The locations of the cannabinoid receptors are most revealing of the way THC acts on the brain, but the importance of this determination is best understood in comparison with the effects of other drugs on the brain. CANNABINOID RECEPTORS
Research has enabled scientists to know which portions of the brain control various body functions, and this knowledge has been used to explain the pharmacological properties of drugs that activate receptor sites in the brain.

There is one study by Gardner and Lowinson, involving inbred Lewis rats, in which doses of THC lowered the amount of electrical stimulation required to trigger the brain reward system. However, no one has been able to replicate the results with any other species of rat, or any other animal. The finding is believed to be the result of some inbred genetic variation in the inbred species, and is both widely mentioned in the literature and disregarded.

According to Herkenham and his associates, "There are virtually no reports of fatal cannabis overdose in humans. The safety reflects the paucity of receptors in medullary nuclei that mediate respiratory and cardiovascular functions." This is also why cannabinoids have great promise as analgesics or painkillers, in that they do not depress the function of the heart or the lungs. In this respect, they are far superior to opiates, which decrease the entire physiological system because the receptors are all over the medulla as well as the brain.
Marijuana is distinguished from most other illicit drugs by the locations of its brain-receptor sites for two predominant reasons: (1) The lack of receptors in the medulla significantly reduces the possibility of accidental, or even deliberate, death from THC, and (2) the lack of receptors in the mesocorticolimbic pathway significantly reduces the risks of addiction and serious physical dependence. As a therapeutic drug, these features are God's greatest gifts   (Read more)
http://www.pdxnorml.org/brain1.html

Affidavit of Bryan A. Krumm

The human body contains a complex system of cannabinoid receptors and produces its own cannabinoids  forming an endogenous cannabinoid system that is involved in normal homeostasis of the immune system  transmission of pain responses  perception, and mood . It has been shown that dysfunction of the endogenous cannabinoid system is involved in certain disease states . It has also been shown that the use of cannabinoids, such as those found in marijuana, may be effective in treating many of those diseases . It has been shown that different cannabinoids act synergistically to produce greater therapeutic effect than single cannabinoid therapy. (Read more) http://www.taima.org/en/krumm.htm

The Why Files

We predict you will hear more about cannabinoid receptors, if only because they are so common. CB(1) is "one of the densest receptors in the brain, even including neurotransmitter receptors such as dopamine and serotonin," says Darmani. "CB(1) is found practically everywhere in nerve terminals, where it controls the release of other neurotransmitters.''   (Read more)

http://whyfiles.org/225drug_receptors/index.php?g=3.txt

Cannabinoid Receptors
Cannabis in the Clinic?
The Medical Marijuana Debate

The active compounds in marijuana are similar to a class of molecules in our bodies called endocannabinoids. Both bind to receptors in the brain and throughout the body called cannabinoid receptors. This system influences our immune system, protects nerve cells from premature death, and influences mood, memory, appetite, sleep and movement
"Endocannabinoids regulate every one of the systems in our bodies."
Marijuana contains approximately 66 active compounds with different properties, collectively called cannabinoids. Scientists are currently studying cannabinoids in an effort to understand their individual and combined effects, and their potential benefits.
Who Can Benifit?
Research and anecdotal evidence suggest that there are conditions for which medical marijuana may be the most effective treatment.

"There are different kinds of pain."

Cancer - Relieves nausea during chemotherapy treatment.

AIDS - Increases appetite in patients experiencing severe weight loss.

Neurological disorders (including spinal cord injury and multiple sclerosis) - Reduces pain and spasticity resulting from nerve damage.

Inflammatory pain - Cannabinoids seem to be more effective than opiates in treating long-term, chronic pain (opiates are better for treating short-term acute pain).

Autoimmune diseases (such as arthritis) - Suppresses the immune system resulting in less pain and inflammation  (Read more)

http://gslc.genetics.utah.edu/units/addiction/issues/marijuana.cfm