CB1 receptor-mediated respiratory depression by endocannabinoids.

“Endocannabinoids (ECs) are bioactive lipid mediators acting on two distinct cannabinoid receptors (CB1 and CB2), which are ubiquitously expressed in many tissues including the respiratory system. Despite numerous experimental data showing that cannabinomimetics influence respiration, the role of endogenously produced ECs in respiratory control has not been verified yet. Pulse oximetry was used in the present study to directly measure changes in respiratory parameters during elevation of EC levels. The cannabinoid reuptake inhibitor AM-404 (10mgkg-1, i.v.), but not its vehicle, induced a transient reduction of respiratory rate with a concomitant depression of arterial oxygen saturation and increase in breath distension in wild-type mice. In contrast, CB1 knock-out mice showed no alteration in any of these parameters upon administration of AM-404. Our results imply that the EC system has an important role in the physiological control of respiration by modulating the respiratory rate and consequently influencing arterial oxygen saturation. Furthermore, this mechanism is entirely dependent on CB1 receptors.” https://www.ncbi.nlm.nih.gov/pubmed/28254562]]>

CB2 cannabinoid receptors modulate HIF-1α and TIM-3 expression in a hypoxia-ischemia mouse model.

“The role of CB2 cannabinoid receptors (CB2R) in global brain lesions induced by hypoxia-ischemia (HI) insult is still unresolved. The aim of this study was to evaluate the involvement of CB2R in the behavioural and biochemical underpinnings related to brain damage induced by HI in adult mice, and the mechanisms involved. Our results indicate that CB2R may have a crucial neuroprotective role following HI insult through the modulation of the inflammatory-related HIF-1α/TIM-3 signalling pathway in microglia.” https://www.ncbi.nlm.nih.gov/pubmed/28253997]]>

The Direct Actions of Cannabidiol and 2-Arachidonoyl Glycerol at GABAA Receptors.

“Cannabidiol (CBD) is a major non-intoxicating component of cannabis and possesses anti-epileptic, anxiolytic and anti-hyperalgesic properties. Despite evidence that some endogenous and synthetic cannabinoids interact with GABAA receptors, no-one has yet investigated the effects of CBD. Here we used two-electrode voltage clamp electrophysiology to compare the actions of CBD with those of the major central endocannabinoid, 2-arachidonoyl glycerol (2-AG) on human recombinant GABAA receptors (synaptic α1-6βg2 and extrasynaptic α4β2δ) expressed on Xenopus oocytes. Taken together these results reveal a mode of action of CBD on specifically configured GABAA receptors that may be relevant to the anticonvulsant and anxiolytic effects of the compound.” https://www.ncbi.nlm.nih.gov/pubmed/28249817]]>

Changes in the Brain Endocannabinoid System in Rat Models of Depression.

Image result for Neurotox Res “A growing body of evidence implicates the endocannabinoid (eCB) system in the pathophysiology of depression. The aim of this study was to investigate the influence of changes in the eCB system, such as levels of neuromodulators, eCB synthesizing and degrading enzymes, and cannabinoid (CB) receptors, in different brain structures in animal models of depression using behavioral and biochemical analyses. These findings suggest that dysregulation in the eCB system is implicated in the pathogenesis of depression, although neurochemical changes were linked to the particular brain structure and the factor inducing depression (surgical removal of the olfactory bulbs vs. genetic modulation).” https://www.ncbi.nlm.nih.gov/pubmed/28247204
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