Cannabis ResearchAddThis Social Bookmark Button
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Loading
Get Widget

Role of the endocannabinoid system in energy balance regulation and obesity

The mission of the Endocannabinoid System Network (ECSN) is to serve as a multifaceted educational resource that will help scientists and clinicians understand and communicate the mechanisms and functions of the endocannabinoid system (ECS) integrating knowledge of the cellular/molecular basis with the neural and systemic effects.

Watch short video below


Endocannabinoid System:

an overview

Obesity, particularly abdominal obesity, and the associated cardiometabolic complications, are critical areas of investigation.

The endocannabinoid system helps to regulate the central control of energy balance and peripheral metabolic processes, both of which may contribute to cardiometabolic risk factors.
http://www.endocannabinoid.net



Abstract

 The endogenous cannabinoid system (ECS) is a neuromodulatory system recently recognized to have a role in the regulation of various aspects of eating behavior and energy balance through central and peripheral mechanisms. In the central nervous system, cannabinoid type 1 receptors and their endogenous ligands, the endocannabinoids, are involved in modulating food intake and motivation to consume palatable food. Moreover, the ECS is present in peripheral organs, such as liver, white adipose tissue, muscle, and pancreas, where it seems to be involved in the regulation of lipid and glucose homeostasis.

 Dysregulation of the ECS has been associated with the development of obesity and its sequelae, such as dyslipidemia and diabetes. Conversely, recent clinical trials have shown that cannabinoid type 1 receptor blockade may ameliorate these metabolic abnormalities. Although further investigation is needed to better define the actual mechanisms of action, pharmacologic approaches targeting the ECS may provide a novel, effective option for the management of obesity, type 2 diabetes and cardiovascular disease.

Source - PubMed 

Diseases And Disorders

Proven to have beneficial effects from the use of medical marijuana.

  It is time to replace an ineffective strategy with more humane and efficient drug policies.

  Prohibitionist policies based on eradication, interdiction and criminalization of consumption simply haven't worked.

 Violence and the organized crime associated with the narcotics trade remain critical problems in our countries.

 Latin America remains the world's largest exporter of cocaine and cannabis, and is fast becoming a major supplier of opium and heroin. Today, we are further than ever from the goal of eradicating drugs.

 If you are not a webmaster, chances are you know somebody who is at least a blogger.

You can help save lives with just one click

AddThis Social Bookmark Button

 
It is all about a healthy balance  (click image for info)
 
Does Cannabis Hold the Key?

Treating Cardiometabolic Disease?

Paul E. Szmitko; Subodh Verma

Posted: 03/17/2006; Nat Clin Pract Cardiovasc Med. 2006;3(3):116-117. Ãƒâ€šÃ‚© 2006 Nature Publishing Group

Obesity, particularly visceral adiposity, and its related metabolic and cardiovascular disorders, is a worldwide pandemic. 

The biological properties of one of the most widespread illicit drugs of abuse, marijuana, have been recruited for obesity management. By uncovering the cellular interactions of the cannabinoid tetrahydrocannabinol (THC Delta 9), the major active component of marijuana researchers have identified new molecular pathways for treating cardiometabolic disease.

Studies have demonstrated that modulation of the endocannabinoid system holds great therapeutic promise for the treatment of obesity, dyslipidemia, insulin resistance and atherosclerosis.

The endocannabinoid system contributes to the regulation of food intake, energy balance, inflammation, and lipid and glucose metabolism, and might therefore play a fundamental role in the development of obesity and atherosclerosis. 

To date, two G-protein-coupled cannabinoid receptors that bind tetrahydrocannabinol (THC Delta 9) with equal affinity have been identified: CB1 and CB2. The CB1 receptor, believed to mediate the psychotropic effects of cannabis and to participate in the modulation of food intake and adipogenesis, is expressed at high levels by brain cells and by several peripheral tissues including the gastrointestinal tract, the adrenal gland, the heart and adipose tissue. CB1 knockout mice exhibit a lean phenotype and appear to be resistant to diet-induced obesity and insulin resistance. 

By contrast, CB2 receptors are located primarily on blood cells and immune tissues, and stimulation of these receptors with tetrahydrocannabinol (THC Delta 9) results in an immunosuppressive phenotype via the modulation of immune-cell cytokine production This molecular system might have a role in the development of obesity, the metabolic syndrome and atherosclerosis, and its modulation might form the basis of new therapeutic strategies for these pathophysiologically linked conditions.

Using apolipoprotein E knockout mice Steffens et al. demonstrated that tetrahydrocannabinol (THC Delta 9) can protect against the development of atherosclerosis.CB2 receptors were expressed in both human and mouse atherosclerotic lesions, but were absent in nondiseased arteries.

Apolipoprotein E knockout mice fed a high cholesterol diet developed extensive atherosclerotic lesions in the aortic root; however, when 1 mg/kg tetrahydrocannabinol (THC Delta 9) daily was added to the dieta dose not associated with CB1 activation and psychotropic effectsa significant reduction in the progression of atherosclerotic lesions was observed. Concomitant CB2 receptor antagonist treatment abolished this observed anti-atherosclerotic effect.

Even though tetrahydrocannabinol (THC Delta 9)-fed mice continued to have elevated serum lipid levels, fewer inflammatory cells were recruited into atherosclerotic lesions, suggesting that tetrahydrocannabinol (THC Delta 9) treatment had a beneficial effect on the inflammatory milieu. Indeed, Steffens and co-workers demonstrated that the immunosuppressive properties of tetrahydrocannabinol (THC Delta 9) interfered with the adhesion, migration, proliferation and function of immune cells involved in atherosclerotic plaque formation.

These promising results do not imply that smoking marijuana is the key to a healthy heart. Too often there is failure to translate promising results observed in murine models to human patients. The effects of tetrahydrocannabinol (THC Delta 9) on atherogenesis in man have not been studied, so whether this cannabinoid does more cardiovascular harm than good remains to be seen.

The beneficial effects of tetrahydrocannabinol (THC Delta 9) observed by Steffens et al. followed a U-shaped distribution with a very narrow therapeutic window, suggesting that the blood concentrations of tetrahydrocannabinol (THC Delta 9) obtained from smoking marijuana would be too variable to provide sustained clinical benefit.

Furthermore, it is unlikely that purified tetrahydrocannabinol (THC Delta 9) extract or marijuana would be legalized for use as an adjunctive treatment of cardiovascular disease, since both compounds could serve as drugs of abuse. 

In addition, smoking marijuana increases carboxyhemoglobin levels, and tetrahydrocannabinol (THC Delta 9) activation of CB1 receptors induces a cardiovascular stress response; raising heart rate and blood pressure, decreasing the anginal threshold, and promoting acute coronary syndromes. 

Overall, smoking marijuana probably has a negative effect on the cardiovascular system. For these reasons, therapeutic strategies using the apparent anti-inflammatory properties of tetrahydrocannabinol (THC Delta 9) will probably depend upon developing specific CB2-receptor agonists, to prevent the onset of psychotropic effects. Once thoroughly tested in animal models, translation to human trials could see the positive effects reported by Steffens et al. clinically realized.

Activation of the endocannabinoid system through the CB1 receptor plays an important role in central and peripheral regulation of energy balance, body weight and food intake.

Blockade of the CB1 receptor appears to offer great promise in cardiometabolic risk reduction, and 1-year results from the RIO program are very encouraging.

In this trial, 1,507 patients with a BMI of at least 30 kg/m2, or at least 27 kg/m2 or more with treated or untreated dyslipidemia, hypertension or both, received double-blind treatment with 5 mg rimonabant, a selective CB1 receptor blocker daily, 20 mg rimonabant daily, or placebo, in addition to a hypocaloric diet.

Treatment with 20 mg rimonabant for 1 year significantly decreased total body weight and waist circumference, and produced a significant weight-independent effect on lipid parameters and several other cardiovascular risk factors. 

The beneficial changes to the lipid profile remained significant after adjusting for weight loss. Furthermore, treatment resulted in a significant reduction in fasting plasma glucose, fasting plasma insulin, insulin resistance and the proportion of patients who fulfilled the criteria for the metabolic syndrome compared with placebo. 

To explain the observed weight-independent effect on both lipid and glycemic variables, Van Gaal et al. hypothesized that enhanced rimonabant-induced expression of adiponectina cytokine that has a role in the regulation of hyperglycemia, hyperinsulinemia and fatty acid oxidation and is reduced in obese individuals could be responsible. Thus, by improving adipocyte function, rimonabant might contribute to beneficial changes in other adipokines, such as C-reactive protein, reinforcing the link between obesity and atherosclerosis.

Further investigation of in vivo effects of rimonabant are required to fully elucidate this mechanism, especially given the concern that CB1 antagonists might raise blood pressure. Furthermore, rimonabant appears to be a useful agent for smoking cessation, yet another cardiac risk factor.

Thus, pharmacologic manipulation of cannabinoid-receptor signaling might combat the development of atherosclerosis through the treatment of obesity, the metabolic syndrome, vascular inflammation and smoking. 

The beneficial effects with rimonobant appear to be consistent in over 6,600 patients enrolled in the RIO program. 

Patients administered this drug enjoy sustained reductions in weight, BMI and visceral adiposity, and improvements in insulin sensitivity and dyslipidemia. More importantly, the beneficial effects to counter insulin resistance, improve dyslipidemia and increase adiponectin, are only partly explained by the reduction in weight, indicating a potential direct role for CB1 in adipogenesis and lipid derangement.


The results of the RIO program and the study by Steffens et al. indicate that modulating the activity of the endocannabinoid system holds promise as an approach to treating obesity, dyslipidemia and atherogenesis. 

The CB1 and CB2 receptors might have opposing effects on atherogenesis: whereas central CB1-receptor blockade offers hope for atherogenic risk reduction, peripheral CB2-receptor stimulation in animals has powerful anti-atherosclerotic effects.

It is possible that a strategy of CB1-receptor antagonism and CB2-receptor agonism might emerge as the most effective treatment across the spectrum of insulin resistance and vascular disease. 

It is paradoxical that studying the effects of cannabis, an illicit drug that provides society with numerous social problems, could serve as the basis for novel therapeutic strategies to reduce cardiometabolic risk.
 

References

  1. Steffens S et al. (2005) Low dose oral cannabinoid therapy reduces progression of atherosclerosis in mice. Nature 434: 782-786
  2. Van Gaal LF et al. (2005) Effects of the cannabinoid-1 receptor blocker rimonabant on weight reduction and cardiovascular risk factors in overweight patients: 1-year experience from the RIO-Europe study. Lancet 365: 1389-1397
  3. Di Marzo V et al. (2004) The endocannabinoid system and its therapeutic exploitation. Nat Rev Drug Discov 3: 771-784
  4. Osei-Hyiaman D et al. (2005) Endocannabinoid activation at hepatic CB1 receptors stimulates fatty acid synthesis and contributes to diet-induced obesity. J Clin Invest 115: 1298-1305
  5. Klein TW (2005) Cannabinoid-based drugs as anti-inflammatory therapeutics. Nat Rev Immunol 5: 400-411
  6. Roth MD (2005) Pharmacology: marijuana and your heart. Nature 434: 708-709
  7. Lau DCW et al. (2005) Adipokines: molecular links between obesity and atherosclerosis. Am J Physiol Heart Circ Physiol 288: 2031-2041
  8. Batkai S et al. (2004) Endocannabinoids acting at cannabinoid-1 receptors regulate cardiovascular function in hypertension. Circulation 110: 1996-2002
  9. Le Foll B et al. (2004) Rimonabant, a CB1 antagonist, blocks nicotine-conditioned place preferences. Neuroreport 15: 2139-2143

 

 Correspondence: Subodh Verma, Division of Cardiac Surgery, St Michael's Hospital 8th floor Bond Wing, 30 Bond Street, Toronto, ON M5B 1W8, Canada. Email: [email protected]

PE Szmitko is a Resident in the Division of General Internal Medicine, and S Verma is a Scientist and Assistant Professor in the Division of Cardiac Surgery, St Michael's Hospital, at the University of Toronto, Toronto, ON, Canada.

source

A Very Good Read

This internationally renowned author team provides a unique and thorough analysis and distillation of the endocannabinoid system and its relationship to abdominal obesity, diabetes, and cardiovascular disease. The endocannabinoid system (ECS) plays an important role in cardiometabolic risk, as well as modulating energy balance, feeding behavior, hepatic lipogenesis, and perhaps glucose homeostasis. Evidence suggests that the ECS is overactive in human obesity and dyslipidemia.

Critical to the management of cardiometabolic risk, this new, timely book provides practical overviews and management guidance on many important topics, including:
 

  • abdominal obesity and the metabolic syndrome
  • the endocannabinoid system and energy balance: functions and dysfunctions
  • abdominal obesity, the EC system, and cardiometabolic risk

Abdominal Obesity and the Endocannabinoid System




 

 

 Top
Home