“Characterized by chronic widespread pain, generalized hyperalgesia, and psychological stress fibromyalgia (FM) is difficult to diagnose and lacks effective treatments. The endocannabinoids – arachidonoylethanolamide (AEA), 2-arachidonoylglycerol (2-AG), and the related oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and stearoylethanolamide (SEA) – are endogenous lipid mediators with analgesic and anti-inflammatory characteristics, in company with psychological modulating properties (e.g., stress and anxiety), and are included in a new emerging “ome”, the endocannabinoidome. This case -control study compared the concentration differences of AEA, OEA, PEA, SEA, and 2-AG in 104 women with FM and 116 healthy controls (CON). All participants OEArated their pain, anxiety, depression, and current health status. The relationships between the lipid concentrations and the clinical assessments were investigated using powerful multivariate data analysis and traditional bivariate statistics. The concentrations of OEA, PEA, SEA, and 2-AG were significantly higher in FM than in CON; significance remained for OEA and SEA after controlling for BMI and age. 2-AG correlated positively with FM duration and BMI, and to some extent negatively with pain, anxiety, depression, and health status. In FM, AEA correlated positively with depression ratings. The elevated circulating levels of endocannabinoidome lipids suggest that these lipids play a role in the complex pathophysiology of FM and might be signs of ongoing low-grade inflammation in FM. Although the investigated lipids are significantly altered in FM their biological roles are uncertain with respect to the clinical manifestations of FM. Thus, plasma lipids alone are not good biomarkers for FM.
Category Archives: Chronic Inflammatory and Neuropathic Pain
Cannabinoid receptor type 1 in the brain regulates the affective component of visceral pain in mice.
“Endocannabinoids acting through cannabinoid receptor type 1 (CB1) are major modulators of peripheral somatic and visceral nociception. Although only partially studied, some evidence suggests a particular role of CB1 within the brain in nociceptive processes.
As the endocannabinoid system regulates affect and emotional behaviors, we hypothesized that cerebral CB1 influences affective processing of visceral pain-related behaviors in laboratory animals.
To study nocifensive responses modulated by supraspinal CB1, we used conditional knock-out mice lacking CB1 either in cortical glutamatergic neurons (Glu-CB1-KO), or in forebrain GABAergic neurons (GABA-CB1-KO), or in principle neurons of the forebrain (CaMK-CB1-KO). These mutant mice and mice treated with the CB1 antagonist SR141716 were tested for different pain-related behaviors. In an acetic acid-induced abdominal constriction test, supraspinal CB1 deletions did not affect nocifensive responses. In the cerulein-model of acute pancreatitis, mechanical allodynia or hyperalgesia were not changed, but Glu-CB1- and CaMK-CB1-KO mice showed significantly increased facial grimacing scores indicating increased affective responses to this noxious visceral stimulus. Similarly, these brain-specific CB1 KO mice also showed significantly changed thermal nociception in a hot-plate test.
These results reveal a novel, and important role of CB1 expressed by cortical glutamatergic neurons in the affective component of visceral nociception.”
https://www.ncbi.nlm.nih.gov/pubmed/29885522
[Cannabinoids in pain medicine]
“The endocannabinoid system (ECS) controls a large number of vital functions. Suboptimal tone of the ECS in certain regions of the nervous system may be associated with disorders that are also associated with pain. Pain and inflammation processes can be modulated by the exogenous supply of cannabinoids. Low-to-moderate pain-relieving effects and in individual cases large pain-relieving effects were observed in randomized, controlled studies of various types of chronic pain. People with chronic neuropathic pain and stress symptoms seem to particularly benefit. The therapeutic range of cannabinoids is small; often small doses are sufficient for clinically significant effects. The “Cannabis-als-Medizin-Gesetz” (cannabis as medicine law) allows the prescription of cannabis preparations under certain conditions. Available data indicate good long-term efficacy and tolerability. However, there is little systematic long-term experience from clinical studies.” https://www.ncbi.nlm.nih.gov/pubmed/29881935 https://link.springer.com/article/10.1007%2Fs00482-018-0299-1]]>
Ventilatory-depressant effects of opioids alone and in combination with cannabinoids in rhesus monkeys.
“Pain is a serious health problem that is commonly treated with opioids, although the doses of opioids needed to treat pain are often similar to those that decrease respiration. Combining opioids with drugs that relieve pain through non-opioid mechanisms can decrease the doses of opioids needed for analgesia, resulting in an improved therapeutic window, but only if the doses of opioids that decrease respiration are not similarly decreased. Using small doses of opioids to treat pain has the potential to reduce the number of overdoses and deaths.
This study investigated whether the cannabinoid receptor agonists Δ9-tetrahydrocannabinol (Δ9-THC) and CP 55,940 modify the ventilatory-depressant effects of morphine and fentanyl in three monkeys.
In summary, cannabinoid receptor agonists, which increase the potency of opioids to produce antinociception, did not increase their potency to depress ventilation. Thus, the therapeutic window is greater for opioids when they are combined with cannabinoid receptor agonists, indicating a possible advantage for these drug mixtures in treating pain.”
https://www.ncbi.nlm.nih.gov/pubmed/29807027
https://www.sciencedirect.com/science/article/pii/S0014299918303108
“Medicinal cannabis registries typically report pain as the most common reason for use. It would be clinically useful to identify patterns of cannabis treatment in migraine and headache, as compared to arthritis and chronic pain, and to analyze preferred cannabis strains, biochemical profiles, and prescription medication substitutions with cannabis.
“Epidermolysis bullosa is a rare blistering skin disorder that is challenging to manage because skin fragility and repeated wound healing cause itching, pain, limited mobility, and recurrent infections.
“Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of chronic pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine.
Cannabidiol is a nonpsychotropic plant constituent of Cannabis sativa.
As we hypothesized that non-CB receptor mechanisms of cannabidiol might contribute to its anti-inflammatory and neuroprotective effects, we investigated the interaction of cannabidiol with strychnine-sensitive alpha(1 )and alpha(1)beta glycine receptors by using the whole-cell patch clamp technique.
Cannabidiol showed a positive allosteric modulating effect in a low micromolar concentration range (EC(50) values: alpha(1) = 12.3 +/- 3.8 micromol/l and alpha(1)beta = 18.1 +/- 6.2 micromol/l). Direct activation of glycine receptors was observed at higher concentrations above 100 micromol/l (EC(50) values: alpha(1) = 132.4 +/- 12.3 micromol/l and alpha(1)beta = 144.3 +/- 22.7 micromol/l).
These in vitro results suggest that strychnine-sensitive glycine receptors may be a target for cannabidiol mediating some of its anti-inflammatory and neuroprotective properties.”