The endocannabinoid system in the physiology and pathophysiology of the gastrointestinal tract.

“Numerous investigations have recently demonstrated the important roles of the endocannabinoid system in the gastrointestinal (GI) tract under physiological and pathophysiological conditions.

 In the GI tract, cannabinoid type 1 (CB1) receptors are present in neurons of the enteric nervous system and in sensory terminals of vagal and spinal neurons, while cannabinoid type 2 receptors are located in immune cells. Activation of CB1 receptors was shown to modulate several functions in the GI tract, including gastric secretion, gastric emptying and intestinal motility.

Under pathophysiological conditions induced experimentally in rodents, the endocannabinoid system conveys protection to the GI tract (e.g. from inflammation and abnormally high gastric and enteric secretions).

Such protective activities are largely in agreement with anecdotal reports from folk medicine on the use of Cannabis sativa extracts by subjects suffering from various GI disorders.

 Thus, the endocannabinoid system may serve as a potentially promising therapeutic target against different GI disorders, including frankly inflammatory bowel diseases (e.g. Crohn’s disease), functional bowel diseases (e.g. irritable bowel syndrome) and secretion- and motility-related disorders.

As stimulation of this modulatory system by CB1 receptor agonists can lead to unwanted psychotropic side effects, an alternative and promising avenue for therapeutic applications resides in the treatment with CB1 receptor agonists that are unable to cross the blood-brain barrier, or with compounds that inhibit the degradation of endogenous ligands (endocannabinoids) of CB1 receptors, hence prolonging the activity of the endocannabinoid system.”

http://www.ncbi.nlm.nih.gov/pubmed/16133420

Medical cannabis: the opportunity versus the temptation.

“The cannabis plant has been known to humanity for centuries as a remedy for pain, diarrhea, and inflammation. Current research has shown cannabis to be a useful remedy for many diseases, including multiple sclerosis, dystonia, and chronic pain.

 Cannabinoids are used to improve food intake in anorexia of AIDS patients and to prevent vomiting due to cancer chemotherapy. In inflammatory conditions cannabinoids improve pain in rheumatoid arthritis and pain and diarrhea in Crohn’s disease. Cannabinoids reduce the size of brain infarct and cardiac reperfusion injury. However, cannabinoid treatment is not free of side effects including euphoria, psychosis, anxiety, paranoia, dependence and abuse.

Since the cannabinoid system is involved in many physiological and pathological processes, the therapeutic potential is great. We must not be blind to the opportunity offered to us by medical cannabis just because it is an illicit drug, nor should we be temped by the quick response of patients to the central effect of cannabis. More research is warranted to explore the full potential of cannabis as medicine.”

http://www.ncbi.nlm.nih.gov/pubmed/22352284

[The modulatory role of endocannabinoids in sleep].

“The endogenous cannabinoid, or endocannabinoid, system is present in the central nervous system (CNS) of rodents and humans. This system includes receptors, endogenous ligands and enzymes. The presence of cannabinoid receptors, called CB1, in the CNS has been reported in the cerebral cortex, the hippocampus, the cerebellum and the brain stem. This neuroanatomical location suggests that this receptor could modify several physiological functions, such as the consolidation of memory, motor control and the generation of sleep.

 

Recent reports have described the presence of lipids in the CNS that bind to the CB1 receptor. Administration of said molecules induces cannabimimetic effects, and hence it has been suggested that these lipids are endogenous cannabinoids or endocannabinoids. Anandamide, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine are molecules that belong to the endocannabinoid family. Anandamide has received more attention from researchers because it was the first endocannabinoid to be reported. Pharmacological experiments have shown that this endocannabinoid induces several different intracellular and behavioural changes.

CONCLUSIONS:

In this study, we review the most important pharmacological aspects of exogenous cannabinoids and the neurobiological role played by the endocannabinoid system, including endogenous and exogenous ligands and receptors. We also examine their pharmacological effects on different behaviours, with particular attention given to the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18297624

The role of the CB1 receptor in the regulation of sleep.

“During the 1990s, transmembranal proteins in the central nervous system (CNS) that recognize the principal compound of marijuana, the delta-9-tetrahydrocannabinol (Delta9-THC) were described. The receptors were classified as central or peripheral, CB1 and CB2, respectively. To this date, it has been documented the presence in the CNS of specific lipids that bind naturally to the CB1/CB2 receptors.

The family of endogenous cannabinoids or endocannabinoids comprises oleamide, arachidonoylethanolamine, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine. Pharmacological experiments have shown that those compounds induce cannabimimetic effects. Endocannabinoids are fatty acid derivates that have a variety of biological actions, most notably via activation of the cannabinoid receptors. The endocannabinoids have an active role modulating diverse neurobiological functions, such as learning and memory, feeding, pain perception and sleep generation.

Experimental evidence shows that the administration of Delta9-THC promotes sleep.

 The activation of the CB1 receptor leads to an induction of sleep, this effect is blocked via the selective antagonist.

Since the system of the endogenous cannabinoids is present in several species, including humans, this leads to the speculation of the neurobiological role of the endocannabinoid system on diverse functions such as sleep modulation.

This review discusses the evidence of the system of the endocannabinoids as well as their physiological role in diverse behaviours, including the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18514375

Proof of Concept Trial of Dronabinol in Obstructive Sleep Apnea

“… Δ9-TetraHydroCannabinol (Δ9THC) stabilizes autonomic output during sleep, reduces spontaneous sleep-disordered breathing, and blocks serotonin-induced exacerbation of sleep apnea. On this basis, we examined the safety, tolerability, and efficacy of dronabinol (Δ9THC), an exogenous Cannabinoid type 1 and type 2 (CB1 and CB2) receptor agonist in patients with Obstructive Sleep Apnea (OSA)…

Conclusion: Dronabinol treatment is safe and well-tolerated in OSA patients at doses of 2.5–10mg daily and significantly reduces AHI in the short-term. These findings should be confirmed in a larger study in order to identify sub-populations with OSA that may benefit from cannabimimetic pharmacologic therapy…

This proof of concept study demonstrates that dronabinol is safe, well-tolerated, and reduces AHI by approximately a third over 3 weeks of oral administration. Dronabinol treatment may be a viable alternative or adjunctive therapy in selected patients with OSA.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550518/

Functional role for cannabinoids in respiratory stability during sleep.

“Serotonin, acting in the peripheral nervous system, can exacerbate sleep-related apnea, and systemically administered serotonin antagonists reduce sleep-disordered respiration in rats and bulldogs. Because cannabinoid receptor agonists are known to inhibit the excitatory effects of serotonin on nodose ganglion cells, we examined the effects of endogenous (oleamide) and exogenous (delta9-tetrahydrocannabinol; delta9THC) cannabimimetic agents on sleep-related apnea…

Our data show that delta9THC and oleamide each stabilized respiration during all sleep stages… This observation suggests an important role for endocannabinoids in maintaining autonomic stability during sleep…

CONCLUSIONS:

This study demonstrates potent suppression of sleep-related apnea by both exogenous and endogenous cannabinoids. These findings are of relevance to the pathogenesis and pharmacological treatment of sleep-related breathing disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/12071539

Circulating anandamide and blood pressure in patients with obstructive sleep apnea.

” OBJECTIVE: Obstructive sleep apnea chronically increases blood pressure through sympathetic nervous system activation. In animals, hypertension and sympathetic activity are restrained by cannabinoid receptor activation. Therefore, we hypothesized that increased blood pressure in patients with obstructive sleep apnea is associated with increased circulating endocannabinoid concentrations.

 

CONCLUSION: Obstructive sleep apnea patients show positive correlations between blood pressure and venous anandamide concentrations independent of confounding factors. Our data suggest a previously not recognized role of the endocannabinoid system for blood pressure regulation in patients with high risk for hypertension and cardiovascular disease.”

http://www.ncbi.nlm.nih.gov/pubmed/23032139

Circulating endocannabinoids and N-acyl-ethanolamides in patients with sleep apnea–specific role of oleoylethanolamide.

“OBJECTIVE:  The endocannabinoid system promotes diverse effects on fat and glucose metabolism as well as on energy balance and sleep regulation. The role of N-acylethanolamides like oleoylethanolamide (OEA) and other endocannabinoids such as anandamide (AEA) and 2-arachidonyl-glycerol (2-AG) has not yet been investigated in patients with sleep apnea.

 

CONCLUSIONS: These results indicate that among the three analyzed fatty acid derivatives, OEA plays a specific role in patients with sleep apnea. Together with animal data, the 2-fold elevation of OEA serum concentrations could be interpreted as a neuroprotective mechanism against chronic oxidative stressors and a mechanism to promote wakefulness in patients with nocturnal sleep deprivation and daytime hypersomnolence.”

http://www.ncbi.nlm.nih.gov/pubmed/20429051

 

[A study on the endogenous cannabinoid system synthetic and catabolic enzyme levels in patients with obstructive sleep apnea].

“OBJECTIVE: To observe the differences of endogenous cannabinoid system (ECS) synthetic and catabolic enzyme levels between the obstructive sleep apnea syndrome (OSA) patients and the control subjects.

 

CONCLUSION: OSA altered the expression of the ECS synthetic and catabolic enzymes, leading to an increase in endogenous cannabinoid substances.”

 

http://www.ncbi.nlm.nih.gov/pubmed/21729625

Expression of the cannabinoid type I receptor and prognosis following surgery in colorectal cancer.

“The cannabinoid system has been considered to be a potential target of colorectal carcinoma therapy. The aim of this study was to address the correlation between cannabinoid type 1 (CB1) receptor expression and disease severity/outcomes in patients with colorectal cancer (CRC).”

An external file that holds a picture, illustration, etc.
Object name is OL-05-03-0870-g00.jpg

 “…The high immunoreactivity of the cannabinoid type 1 receptor is a significant prognostic factor following surgery in stage IV CRC…

The effect of cannabinoids in colorectal cancer (CRC) has been demonstrated in in vitro experiments and animal models, which indicate the antiproliferative, apoptotic and antimetastatic actions of cannabinoid agonists…

Antineoplastic effects are mediated by the activation of cannabinoid type I (CB1), type 2 (CB2) or a non-cannabinoid receptor-mediated mechanism…”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3576207/