On this site you will find clinical studies with cannabis or single
cannabinoids in different diseases and case reports on the use of cannabis by
You may search for diseases (indications), authors, medication,
study design (controlled study, open trial, case report etc.) and other criteria.
|Title||Decreased Cannabinoid CB1 Receptors in Male Tobacco Smokers Examined With Positron Emission Tomography.|
|Author(s)||Hirvonen J, et al. |
|Journal, Volume, Issue||Biol Psychiatry. [Epub ahead of print]|
|Major outcome(s)||Tobacco smokers have reduced concentrations of brain CB1 receptors|
Previous studies showed reduction of brain cannabinoid CB1 receptors in adults with cannabis and alcohol use disorders. Preclinical data suggest that these receptors also contribute to nicotine reward and dependence. Tobacco smoking may confound clinical studies of psychiatric disorders because many patients with such disorders smoke tobacco. Whether human subjects who smoke tobacco but are otherwise healthy have altered CB1 receptor binding in brain is unknown.
We measured CB1 receptors in brains of 18 healthy men who smoke tobacco (frequent chronic cigarette smokers), and 28 healthy men who do not smoke tobacco, using positron emission tomography and [18F]FMPEP-d2, a radioligand for CB1 receptors. We collected arterial blood samples during scanning to calculate the distribution volume (VT), which is nearly proportional to CB1 receptor density. Repeated-measures analysis of variance compared VT between groups in various brain regions.
Brain CB1 receptor VT was about 20% lower in subjects who smoke tobacco than in subjects who do not. Decreased VT was found in all brain regions, but reduction did not correlate with years of smoking, number of cigarettes smoked per day, or measures of nicotine dependence.
Tobacco-smoking healthy men have a widespread reduction of CB1 receptor density in brain. Reduction of CB1 receptors appears to be a common feature of substance use disorders. Future clinical studies on the CB1 receptor should control for tobacco smoking.
|Type of publication||Medical journal|
|Address of author(s)|