Alterations in plasma endocannabinoid concentrations among individuals with major depression treated with electroconvulsive therapy.

The role of the endocannabinoid system (ECS) in depression and suicidality has recently emerged. The purpose of the study was to identify changes in plasma endocannabinoid concentrations of several endocannabinoids and correlate them with depressive symptoms and suicidality in patients with severe major depression undergoing electroconvulsive therapy (ECT). The study included 17 patients that were evaluated in four visits at different stages of therapy. At each visit depression, anxiety and suicidality symptoms were assessed and blood samples collected. Several endocannabinoid concentrations increased following six sessions of ECT, as 2-AG (p < 0.05) and LEA (p < 0.01), and following twelve sessions of ECT, as 2-AG (p < 0.05), AEA (p < 0.05), LEA (p < 0.05) and DH-Gly (p < 0.05). Endocannabinoids also correlated with symptoms of depression, anxiety and suicidality at baseline and at the sixth ECT session. Finally, we found one endocannabinoid, l-Gly, that differentiated between remitted and not-remitted patients at the seventh and thirteenth ECT sessions (p < 0.05). Our findings suggest that depression is markedly related to imbalance of the endocannabinoid system, and further regulated by ECT. Plasma endocannabinoids could be promising biomarkers for detection of depression response and remission.

CYP4F2 is a human-specific determinant of circulating N-acyl amino acid levels.

N-acyl amino acids are a large family of circulating lipid metabolites that modulate energy expenditure and fat mass in rodents. However, little is known about the regulation and potential cardiometabolic functions of N-acyl amino acids in humans. Here, we analyze the cardiometabolic phenotype associations and genomic associations of four plasma N-acyl amino acids (N-oleoyl-leucine, N-oleoyl-phenylalanine, N-oleoyl-serine, and N-oleoyl-glycine) in 2351 individuals from the Jackson Heart Study. We find that plasma levels of specific N-acyl amino acids are associated with cardiometabolic disease endpoints independent of free amino acid plasma levels and in patterns according to the amino acid head group. By integrating whole genome sequencing data with N-acyl amino acid levels, we identify that the genetic determinants of N-acyl amino acid levels also cluster according to the amino acid head group. Furthermore, we identify the CYP4F2 locus as a genetic determinant of plasma N-oleoyl-leucine and N-oleoyl-phenylalanine levels in human plasma. In experimental studies, we demonstrate that CYP4F2-mediated hydroxylation of N-oleoyl-leucine and N-oleoyl-phenylalanine results in metabolic diversification and production of many previously unknown lipid metabolites with varying characteristics of the fatty acid tail group, including several that structurally resemble fatty acid hydroxy fatty acids. These studies provide a structural framework for understanding the regulation and disease associations of N-acyl amino acids in humans and identify that the diversity of this lipid signaling family can be significantly expanded through CYP4F-mediated ω-hydroxylation.

12,13-diHOME as a new therapeutic target for metabolic diseases.

Lipokines are bioactive compounds, derived from adipose tissue depots, that control several molecular signaling pathways. Recently, 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME), an oxylipin, has gained prominence in the scientific literature. An increase in circulating 12,13-diHOME has been associated with improved metabolic health, and the action of this molecule appears to be mediated by brown adipose tissue (BAT). Scientific evidence indicates that the increase in serum levels of 12,13-diHOME caused by stimuli such as physical exercise and exposure to cold may favor the absorption of fatty acids by brown adipose tissue and stimulate the browning process in white adipose tissue (WAT). Thus, strategies capable of increasing 12,13-diHOME levels may be promising for the prevention and treatment of obesity and metabolic diseases. This review explores the relationship of 12,13-diHOME with brown adipose tissue and its role in the metabolic health context, as well as the signaling pathways involved between 12,13-diHOME and BAT.

Clinical significance of small molecule metabolites in the blood of patients with different types of liver injury.

To understand the characteristic of changes of serum metabolites between healthy people and patients with hepatitis B virus (HBV) infection at different stages of disease, and to provide reference metabolomics information for clinical diagnosis of liver disease patients. 255 patients with different stages of HBV infection were selected. 3 mL blood was collected from each patient in the morning to detect differences in serum lysophosphatidylcholine, acetyl-L-carnitine, oleic acid amide, and glycocholic acid concentrations by UFLC-IT-TOF/MS. The diagnostic values of four metabolic substances were evaluated by receiver operating characteristic (ROC) curve. The results showed that the optimal cut-off value of oleic acid amide concentration of the liver cirrhosis and HCC groups was 23.6 mg/L, with a diagnostic sensitivity of 88.9% and specificity of 70.6%. The diagnostic efficacies of the three substances were similar in the hepatitis and HCC groups, with an optimal cut-off value of 2.04 mg/L, and a diagnostic sensitivity and specificity of 100% and 47.2%, respectively. The optimal cut-off value of lecithin of the HBV-carrier and HCC groups was 132.85 mg/L, with a diagnostic sensitivity and specificity of 88.9% and 66.7%, respectively. The optimal cut-off value of oleic acid amide of the healthy and HCC groups was 129.03 mg/L, with a diagnostic sensitivity and specificity of 88.4% and 83.3%, respectively. Lysophosphatidylcholine, acetyl-L-carnitine, and oleic acid amide were potential metabolic markers of HCC. Among them, lysophosphatidylcholine was low in the blood of HCC patients, and its diagnostic efficacy was better than that of acetyl-L-carnitine and oleic acid amide, providing reference metabolomics information in clinical diagnosis and future research.

Impact of Circulating N-Acylethanolamine Levels with Clinical and Laboratory End Points in Hemodialysis Patients.

BACKGROUND: Patients with ESRD on maintenance hemodialysis (MHD) are particularly susceptible to dysregulation of energy metabolism, which may manifest as protein energy wasting and cachexia. In recent years, the endocannabinoid system has been shown to play an important role in energy metabolism with potential relevance in ESRD. N-acylethanolamines are a class of fatty acid amides which include the major endocannabinoid ligand, anandamide, and the endogenous peroxisome proliferator-activated receptor-α agonists, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA). METHODS: Serum concentrations of OEA and PEA were measured in MHD patients and their correlations with various clinical/laboratory indices were examined. Secondarily, we evaluated the association of circulating PEA and OEA levels with 12-month all-cause mortality. RESULTS: Both serum OEA and PEA levels positively correlated with high-density lipoprotein-cholesterol levels and negatively correlated with body fat and body anthropometric measures. Serum OEA levels correlated positively with serum interleukin-6 (IL-6) (rho = 0.19; p = 0.004). Serum PEA and IL-6 showed a similar but nonsignificant trend (rho = 0.12; p = 0.07). Restricted cubic spline analyses showed that increasing serum OEA and PEA both trended toward higher mortality risk, and these associations were statistically significant for PEA (PEA ≥4.7 pmol/mL; reference: PEA <4.7 pmol/mL) after adjustments in a Cox model (hazard ratio 2.99; 95% confidence interval 1.04, 8.64). CONCLUSIONS: In MHD patients, OEA and PEA are significantly correlated with variables related to lipid metabolism and body mass. Additionally, higher serum levels of PEA are associated with mortality risk. Future studies are needed to examine the potential mechanisms responsible for these findings and their clinical implications.

Temporal trend of circulating trans-fatty acids and risk of long-term mortality in general population.

BACKGROUND & AIMS: There has been controversial evidence regarding the relationship between isomers of circulating trans-fatty acids (TFAs) and mortality. This study aimed to ascertain the relationships between plasma TFAs and overall or cause-specific mortality of the general population in two independent subsets from the US National Health and Nutrition Examination Survey (1999-2000 and 2009-2010 cycles). METHODS AND RESULTS: Plasma TFA isomers (C16:1n-7t, C18:1n-7t, C18:1n-9t and C18:2n-6,9t) in 3439 adults free of cancer or severe cardiovascular disease were analyzed by gas chromatography/mass spectrometry. Overall, 259 died among 1376 individuals over a median follow-up of 15.6 years in the 1999-2000 cycle, and 105 died in the latter subset of 2063 subjects during a median of 5.9 years. Cox proportional hazards regression was conducted to estimate the hazard ratios of mortality. The main isomer of industrially derived TFAs, elaidic acid (C18:1n-9t) was considerably associated with long-term total mortality in the 1999-2000 cycle after adjusting for confounders, with a 54% increase in the top tertile compared with the bottom one. However, the association disappeared with halving C18:1n-9t by 2009-2010. In contrast, neither of the ruminant-derived TFAs (C16:1n-7t and C18:1n-7t) suggested any inverse correlations with all-cause death, mortality due to heart disease, cancer or other causes. CONCLUSION: The major isomer of industrial TFAs, the higher circulating C18:1n-9t might be associated with increased long-term mortality. The associations with death risk turned slight with the reduction of TFAs consumption by half. However, dietary guidelines should rigorously identify the healthy effect of animal TFAs consumption.

Disease-Specific Derangement of Circulating Endocannabinoids and N-Acylethanolamines in Myeloproliferative Neoplasms.

Growing evidence highlights the endocannabinoid (EC) system involvement in cancer progression. Lipid mediators of this system are secreted by hematopoietic cells, including the ECs 2-arachidonoyl-glycerol (2AG) and arachidonoyl-ethanolamide (AEA), the 2AG metabolite 1AG, and members of N-acylethanolamine (NAE) family-palmitoyl-ethanolamide (PEA) and oleoyl-ethanolamide (OEA). However, the relevance of the EC system in myeloproliferative neoplasms (MPN) was never investigated. We explored the EC plasma profile in 55 MPN patients, including myelofibrosis (MF; n = 41), polycythemia vera (PV; n = 9), and essential thrombocythemia (ET; n = 5) subclasses and in 10 healthy controls (HC). AEA, PEA, OEA, 2AG, and 1AG plasma levels were measured by LC-MS/MS. Overall considered, MPN patients displayed similar EC and NAE levels compared to HC. Nonetheless, AEA levels in MPN were directly associated with the platelet count. MF patients showed higher levels of the sum of 2AG and 1AG compared to ET and PV patients, higher OEA/AEA ratios compared to HC and ET patients, and higher OEA/PEA ratios compared to HC. Furthermore, the sum of 2AG and 1AG positively correlated with JAK2V617F variant allele frequency and splenomegaly in MF and was elevated in high-risk PV patients compared to in low-risk PV patients. In conclusion, our work revealed specific alterations of ECs and NAE plasma profile in MPN subclasses and potentially relevant associations with disease severity.

Role of Endocannabinoids in Energy-Balance Regulation in Participants in the Postobese State-a PREVIEW Study.

CONTEXT: Endocannabinoids are suggested to play a role in energy balance regulation. OBJECTIVE: We aimed to investigate associations of endocannabinoid concentrations during the day with energy balance and adiposity and interactions with 2 diets differing in protein content in participants in the postobese phase with prediabetes. DESIGN AND PARTICIPANTS: Participants (n = 38) were individually fed in energy balance with a medium protein (MP: 15:55:30% of energy from protein:carbohydrate:fat) or high-protein diet (HP: 25:45:30% energy from P:C:F) for 48 hours in a respiration chamber. MAIN OUTCOME MEASURES: Associations between energy balance, energy expenditure, respiratory quotient, and endocannabinoid concentrations during the day were assessed. RESULTS: Plasma-concentrations of anandamide (AEA), oleoylethanolamide (OEA), palmitoyethanolamide (PEA), and pregnenolone (PREG) significantly decreased during the day. This decrease was inversely related to body mass index (AEA) or body fat (%) (PEA; OEA). The lowest RQ value, before lunch, was inversely associated with concentrations of AEA and PEA before lunch. Area under the curve (AUC) of concentrations of AEA, 2-AG, PEA, and OEA were positively related to body fat% (P < .05).The HP and MP groups showed no differences in concentrations of AEA, OEA, PEA, and PREG, but the AUC of 2-arachidonoylglycerol (2-AG) was significantly higher in the HP vs the MP group. CONCLUSIONS: In energy balance, only the endocannabinoid 2-AG changed in relation to protein level of the diet, whereas the endocannabinoid AEA and endocannabinoid-related compounds OEA and PEA reflected the gradual energy intake matching energy expenditure during the day.

Increased Anandamide and Decreased Pain and Depression after Exercise in Fibromyalgia.

PURPOSE: Physical exercise is increasingly being promoted by health care for chronic pain conditions with beneficial outcomes, such as pain and fatigue reduction, and increased quality of life. Nevertheless, knowledge about biochemical consequences of physical exercise in chronic pain is still relatively poor. The endocannabinoid system has been suggested to play a role for acute exercise-induced reward and pain inhibition. The aim of this study is to investigate the chronic outcomes of resistance exercise on levels of endocannabinoids and related lipids in fibromyalgia (FM). METHODS: This study examine the outcomes of a 15-wk person-centered resistance exercise program on plasma levels of the lipid mediators; anandamide, 2-arachidonoylglycerol (2-AG), oleoylethanolamide, palmitoylethanolamide, and stearoylethanolamide (SEA) sampled from 37 women with FM and 33 healthy controls. The associations between clinical scorings of pain, depression, anxiety, fatigue, and muscle strength with levels of these lipid mediators before and after the exercise program are also analyzed. RESULTS: After the 15-wk exercise program, anandamide levels were significantly increased, and SEA levels significantly decreased in FM. Pain intensity and depression scorings decreased and muscle strength increased, and in a multivariate context, muscle strength was positively associated with 2-AG levels after the resistance exercise program in FM. CONCLUSIONS: The increased anandamide and decreased SEA in women with FM after the 15-wk program might point to a chronic effect of resistance exercise. Pain and depression scorings decreased in the FM group after the program, but no associations between pain, depression, and lipid level changes were assured.

Impact of circadian rhythmicity and sleep restriction on circulating endocannabinoid (eCB) N-arachidonoylethanolamine (anandamide).

OBJECTIVE: The endocannabinoid (eCB) system is involved in diverse aspects of human physiology and behavior but little is known about the impact of circadian rhythmicity on the system. The two most studied endocannabinoids, AEA (ananamide) and 2-AG (2-arachidonoylglycerol), can be measured in peripheral blood however the functional relevance of peripheral eCB levels is not clear. Having previously detailed the 24-h profile of serum 2-AG, here we report the 24-h serum profile of AEA to determine if these two endocannabinoids vary in parallel across the biological day including a nocturnal 8.5-h sleep period. Further, we assessed and compared the effect of a physiological challenge, in the form of sleep restriction to 4.5-h, on these two profiles. METHODS: In this randomized crossover study, we examined serum concentrations of AEA across a 24-h period in fourteen young adults. Congeners of AEA, the structural analogs oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) were simultaneously assayed. Prior to 24-h blood sampling, each participant was exposed to two nights of normal (8.5 h) or restricted sleep (4.5 h). The two sleep conditions were separated by at least one month. In both sleep conditions, during the period of blood sampling, each individual ate the same high-carbohydrate meal at 0900, 1400, and 1900. RESULTS: Mean 24-h concentrations of AEA were 0.697 ±â€¯0.11 pmol/ml. A reproducible biphasic 24-h profile of AEA was observed with a first peak occurring during early sleep (0200) and a second peak in the mid-afternoon (1500) while a nadir was detected in the mid-morning (1000). The 24-h profiles for both OEA and PEA followed a similar pattern to that observed for AEA. AEA, OEA, and PEA levels were not affected by sleep restriction at any time of day, contrasting with the elevation of early afternoon levels previously observed for 2-AG. CONCLUSIONS: The 24-h rhythm of AEA is markedly different from that of 2-AG, being of lesser amplitude and biphasic, rather than monophasic. These observations suggest distinct regulatory pathways of the two eCB and indicate that time of day needs to be carefully controlled in studies attempting to delineate their relative roles. Moreover, unlike 2-AG, AEA is not altered by sleep restriction, suggesting that physiological perturbations may affect AEA and 2-AG differently. Similar 24-h profiles were observed for OEA and PEA following normal and restricted sleep, further corroborating the validity of the wave-shape and lack of response to sleep loss observed for the AEA profile. Therapeutic approaches involving agonism or antagonism of peripheral eCB signaling will likely need to be tailored according to time of day.

Circulating omega-7 fatty acids are differentially related to metabolic dysfunction and incident type II diabetes: The Multi-Ethnic Study of Atherosclerosis (MESA).

AIM: Determine whether plasma omega-7 vaccenic acid and palmitoleic acid levels are related to homeostasis model of insulin resistance scores and incident type II diabetes, and whether race/ethnicity modifies these associations. METHODS: Plasma phospholipid fatty acids were measured by gas chromatography with flame-ionization detection in Multi-Ethnic Study of Atherosclerosis participants. Linear regression determined associations of vaccenic acid and palmitoleic acid with log-transformed homeostasis model of insulin resistance scores (n=5689), and Cox regression determined associations with incident type II diabetes (n=5413, 660 cases). Race-interactions were tested. RESULTS: Adjusting for typical risk factors, higher levels of plasma vaccenic acid were found to be inversely associated with insulin resistance scores across all four race/ethnicities, and a significant race-interaction was observed between Hispanics and Caucasians (P for interaction=0.03). Vaccenic acid was related to 17%, 32%, and 39% lower risks of incident type II diabetes in Black, Hispanic, and Chinese American participants, respectively. Differences in associations between races were detected (P for interactions<0.05). By contrast, higher levels of plasma palmitoleic acid were related to greater insulin resistance scores in Blacks (P<0.001) and Hispanics (P<0.001); significant race-based differences between associations were detected (P for interactions<0.05). Palmitoleic acid was correspondingly related to a 21% greater risk of incident type II diabetes in Black individuals. CONCLUSIONS: Results suggest that plasma vaccenic acid and palmitoleic acid are markers of metabolic health and dysfunction, respectively. Coupled with previous evidence and the significant race-interactions, our findings have implications for future studies of the race-based differences in omega-7 fatty acids and their regulation in the context of deteriorating metabolic health.

N-acyl taurines are endogenous lipid messengers that improve glucose homeostasis.

Fatty acid amide hydrolase (FAAH) degrades 2 major classes of bioactive fatty acid amides, the N-acylethanolamines (NAEs) and N-acyl taurines (NATs), in central and peripheral tissues. A functional polymorphism in the human FAAH gene is linked to obesity and mice lacking FAAH show altered metabolic states, but whether these phenotypes are caused by elevations in NAEs or NATs is unknown. To overcome the problem of concurrent elevation of NAEs and NATs caused by genetic or pharmacological disruption of FAAH in vivo, we developed an engineered mouse model harboring a single-amino acid substitution in FAAH (S268D) that selectively disrupts NAT, but not NAE, hydrolytic activity. The FAAH-S268D mice accordingly show substantial elevations in NATs without alterations in NAE content, a unique metabolic profile that correlates with heightened insulin sensitivity and GLP-1 secretion. We also show that N-oleoyl taurine (C18:1 NAT), the most abundant NAT in human plasma, decreases food intake, improves glucose tolerance, and stimulates GPR119-dependent GLP-1 and glucagon secretion in mice. Together, these data suggest that NATs act as a class of lipid messengers that improve postprandial glucose regulation and may have potential as investigational metabolites to modify metabolic disease.

Serum elaidic acid concentration and risk of dementia: The Hisayama Study.

OBJECTIVE: The associations between trans fatty acids and dementia have been unclear. We investigated the prospective association between serum elaidic acid (trans 18:1 n-9) levels, as an objective biomarker for industrial trans fat, and incident dementia and its subtypes. METHODS: In total, 1,628 Japanese community residents aged 60 and older without dementia were followed prospectively from when they underwent a screening examination in 2002-2003 to November 2012 (median 10.3 years, interquartile range 7.2-10.4 years). Serum elaidic acid levels were measured using gas chromatography/mass spectrometry and divided into quartiles. The Cox proportional hazards model was used to estimate the hazard ratios for all-cause dementia, Alzheimer disease (AD), and vascular dementia by serum elaidic acid levels. RESULTS: During the follow-up, 377 participants developed some type of dementia (247 AD, 102 vascular dementia). Higher serum elaidic acid levels were significantly associated with greater risk of developing all-cause dementia (p for trend = 0.003) and AD (p for trend = 0.02) after adjustment for traditional risk factors. These associations remained significant after adjustment for dietary factors, including total energy intake and intakes of saturated and polyunsaturated fatty acids (both p for trend <0.05). No significant associations were found between serum elaidic acid levels and vascular dementia. CONCLUSIONS: The findings suggest that higher serum elaidic acid is a possible risk factor for the development of all-cause dementia and AD in later life. Public health policy to reduce industrially produced trans fatty acids may assist in the primary prevention of dementia.

Prediction of preterm labour from a single blood test: The role of the endocannabinoid system in predicting preterm birth in high-risk women.

OBJECTIVE: To determine if plasma concentrations of the N-acylethanolamines (NAEs) N-arachidonoylethanolamine (AEA), N-oleoylethanolamide (OEA) and N-palmitoylethanolamide (PEA) increase in women at high risk for preterm birth (PTB) and whether these could be used to predict preterm delivery and if so, how they compare with current methods. DESIGN: Prospective cohort study. SETTING: A large UK teaching hospital. POPULATION: 217 pregnant women were recruited between 24 and 34 gestational weeks at 'high-risk' for PTB, recruited from a prematurity prevention clinic or antenatal wards. METHODS: Plasma AEA, OEA, and PEA concentrations were measured using ultra-high performance liquid chromatography-tandem mass spectrometry whilst FAAH enzyme activity was measured by fluorometric radiometric assay and CL by ultrasound scan. The clinical usefulness of these measurements were determined by ROC and multivariate analyses. RESULTS: AEA and PEA concentrations were significantly higher in women who delivered prematurely. An AEA concentration >1.095 nM predicted PTB, the gestational age at delivery and the recruitment to delivery interval (RTDI). A PEA concentration >17.50 nM only predicted PTB; FAAH enzyme activity was not related to these changes. Multivariate analysis (all variables) generated an equation to accurately predict the RTDI. CONCLUSIONS: A single plasma AEA or PEA measurement can predict PTB. A single AEA measurement predicts the gestational age of delivery and the remaining period of pregnancy with reasonable accuracy and better than existing conventional tests thus offering a better window for primary prevention of PTB.

Dietary fatty acid profile influences circulating and tissue fatty acid ethanolamide concentrations in a tissue-specific manner in male Syrian hamsters.

BACKGROUND: The discovery of N­acylethanolamines (NAEs) has prompted an increase in research aimed at understanding their biological roles including regulation of appetite and energy metabolism. However, a knowledge gap remains to understand the effect of dietary components on NAE levels, in particular, heterogeneity in dietary fatty acid (DFA) profile, on NAE levels across various organs. OBJECTIVE: To identify and elucidate the impact of diet on NAE levels in seven different tissues/organs of male hamsters, with the hypothesis that DFA will act as precursors for NAE synthesis in golden Syrian male hamsters. METHOD: A two-month feeding trial was performed, wherein hamsters were fed various dietary oil blends with different composition of 18-C fatty acid (FA). RESULTS: DFA directly influences tissue FA and NAE levels. After C18:1n9-enriched dietary treatments, marked increases were observed in duodenal C18:1n9 and oleoylethanolamide (OEA) concentrations. Among all tissues; adipose tissue brown, adipose tissue white, brain, heart, intestine-duodenum, intestine-jejunum, and liver, a negative correlation was observed between gut-brain OEA concentrations and body weight. CONCLUSION: DFA composition influences FA and NAE levels across all tissues, leading to significant shifts in intestinal-brain OEA concentrations. The endogenously synthesized increased OEA levels in these tissues enable the gut-brain-interrelationship. Henceforth, we summarize that the brain transmits anorexic properties mediated via neuronal signalling, which may contribute to the maintenance of healthy body weight. Thus, the benefits of OEA can be enhanced by the inclusion of C18:1n9-enriched diets, pointing to the possible nutritional use of this naturally occurring bioactive lipid-amide in the management of obesity.

Determination of endocannabinoids and endocannabinoid-like substances in human K3EDTA plasma - LC-MS/MS method validation and pre-analytical characteristics.

The determination of endocannabinoids and endocannabinoid-like substances in biological human samples is a vibrant field of research with great significance due to postulated relevance of these substances in diseases such as Alzheimer's disease, multiple sclerosis, cancer and cardiovascular diseases. For a possible use as biomarker in early prediction or diagnosis of a disease as well as examination of a successful treatment, the valid determination of the analytes in common accessible human samples, such as plasma or serum, is of great importance. A method for the determination of arachidonoyl ethanolamide, oleoyl ethanolamide, palmitoyl ethanolamide, 1-arachidonoyl glycerol and 2-arachidonoyl glycerol in human K3EDTA plasma using liquid-liquid-extraction in combination with liquid chromatography-tandem-mass spectrometry has been developed and validated for the quantification of the aforementioned analytes. Particular emphasis was placed on the chromatographic separation of the isomers 1-arachidonoyl glycerol and 2-arachidonoyl glycerol, arachidonoyl ethanolamide and O-arachidonoyl ethanolamine (virodhamine) as well as oleoyl ethanolamide and vaccenic acid ethanolamide. During the validation process, increasing concentrations of 1-arachidonoyl glycerol and 2-arachidonoyl glycerol while storing plasma samples were observed. In-depth investigation of pre-analytical sample handling revealed rising concentrations for both analytes in plasma and for arachidonoyl ethanolamide, oleoyl ethanolamide and palmitoyl ethanolamide in whole blood, dependent on the period and temperature of storage. Prevention of the increase in concentration was not possible, raising the question whether human K3EDTA plasma is suitable for the determination of endocannabinoids and endocannabinoid-like substances. Especially the common practice to calculate the concentration of 2-arachidonoyl glycerol as sum of 1-arachidonoyl glycerol and 2-arachidonoyl glycerol is highly questionable because the concentrations of both analytes increase unequally while storing the plasma samples in the fridge.

Loss of exercise- and stress-induced increases in circulating 2-arachidonoylglycerol concentrations in adults with chronic PTSD.

The endocannabinoid (eCB) system is a modulatory system that is both altered by stress and mediates the effects of acute stress, including contributing to restoration of homeostasis. Earlier studies suggest that circulating eCBs are dysregulated in adults with post-traumatic stress disorder (PTSD); however, it is not known whether circulating eCBs remain responsive to stress. The purpose of this study was to examine eCB and psychological responses to physical (exercise) and psychosocial (Trier Social Stress Test) stressors, using a randomized, counterbalanced procedure in adults with PTSD and healthy controls (N = 20, mean age = 24, SD = 7 yrs). Results from mixed-design, repeated measures ANOVAs revealed significant increases (p < .05) in N-arachidonoylethanolamine (AEA) and oleoylethanolamide (OEA) following exercise and psychosocial stress in both groups. However, only the control group exhibited a significant increase (p < .05) in 2-arachidonoylglycerol (2-AG) following exercise and psychosocial stress exposure. These data extend our current understanding of circulating eCB responsiveness in PTSD, and provide preliminary evidence to suggest that the eCB system is hypoactive in PTSD following exposure to physical and psychosocial stressors.

Serum Endocannabinoid and Mood Changes after Exercise in Major Depressive Disorder.

The endocannabinoid (eCB) system is implicated in the pathophysiology of depression and is responsive to acute exercise in healthy adults. PURPOSE: We aimed to describe acute changes in serum eCB across a prescribed moderate (MOD) and a self-selected/preferred (PREF) intensity exercise session in women with major depressive disorder (MDD) and determine relationships between changes in eCB and mood states. METHODS: Women with MDD (n = 17) exercised in separate sessions for 20 min on a cycle ergometer at both MOD or PREF in a within-subjects design. Blood was drawn before and within 10 min after exercise. Serum concentrations of eCB (anandamide [AEA], 2-arachidonoylglycerol) and related lipids (palmitoylethanolamine, oleoylethanolamine, 2-oleoylglycerol) were quantified using stable isotope-dilution, liquid chromatography/mass spectrometry/mass spectrometry. The profile of mood states and state-trait anxiety inventory (state only) were completed before, 10 min and 30 min postexercise. RESULTS: Significant elevations in AEA (P = 0.013) and oleoylethanolamine (P = 0.024) occurred for MOD (moderate effect sizes: Cohen's d = 0.58 and 0.41, respectively). Significant (P < 0.05) moderate negative associations existed between changes in AEA and mood states for MOD at 10 min (depression, confusion, fatigue, total mood disturbance [TMD] and state anxiety) and 30 min postexercise (confusion, TMD and state anxiety). Significant (P < 0.05) moderate negative associations existed between 2-arachidonoylglycerol and mood states at 10 min (depression and confusion) and 30 min postexercise (confusion and TMD). Changes in eCB or related lipids or eCB-mood relationships were not found for PREF. CONCLUSION: Given the broad, moderate-strength relationships between improvements in mood states and eCB increases after MOD, it is plausible that the eCB system contributes to the mood-enhancing effects of prescribed acute exercise in MDD. Alternative mechanisms are likely involved in the positive mood state effects of preferred exercise.

Elevated Serum Elaidic Acid Predicts Risk of Repeat Revascularization After Percutaneous Coronary Intervention in Japan.

BACKGROUND: Trans-fatty acid (TFA) intake increases the risk of coronary artery disease (CAD). Our previous cross-sectional survey showed that middle-aged patients with CAD in Japan have elevated serum TFA. In this study, we longitudinally investigated whether elevated TFA is a risk factor in the secondary prevention of CAD for the same-age patients. Methods and Results: A total of 112 patients (age, 21-66 years) who underwent percutaneous coronary intervention were followed up for up to 2 years. Serum elaidic acid was measured using gas chromatography/mass spectrometry as a marker of TFA intake and divided into quartiles. The primary endpoint was ischemia-driven target lesion revascularization (TLR). The hazard ratio (HR) for TLR increased significantly with higher serum elaidic acid (P<0.01). The significant positive trend remained unchanged after adjusting for conventional lipid profile and bare-metal stent usage. In contrast, although triglycerides and low-density lipoprotein cholesterol were positively correlated with elaidic acid, they were not associated with TLR. On multivariable Cox proportional hazard analysis, elevated elaidic acid was independently associated with TLR risk after adjusting for conventional coronary risks (HR, 10.7, P<0.01). CONCLUSIONS: Elevated elaidic acid is associated with higher TLR rate in middle-aged patients with CAD, suggesting that excessive TFA intake is becoming a serious health problem in Japan.

Plasma concentrations of oleoylethanolamide in a primary care sample of depressed patients are increased in those treated with selective serotonin reuptake inhibitor-type antidepressants.

Oleoylethanolamide (OEA) is a non-cannabinoid acylethanolamide with multiple physiological roles that has been proposed to have antidepressant-like activity in preclinical models. OEA shares biosynthetic pathways with anandamide (AEA) a transmitter involved in affective disorders and anxiety in humans. However, although the participation of OEA in depression has been proposed, both, the contribution of OEA to the depressive phenotype and the effect of antidepressant therapy on circulating levels of this and related non-cannabinoid acylethanolamides in humans are basically unknown. The main objective of this study is to compare the plasma concentrations of OEA and related acylethanolamides in a sample of primary care patients with depression (n = 69) with those of healthy non-depressed patients (n = 47). At the time of admission to the study, 22 patients were under selective serotonin reuptake inhibitor (SSRI) antidepressant treatment and 47 patients were not receiving any type of intervention. In addition, plasma concentrations of the endocannabinoid 2-AG and two related monoacylglycerols were monitored. Plasma OEA concentrations were found to be elevated in depressed patients and to correlate with somatic symptoms of depression. Plasma concentrations of both, AEA and 2-AG, were found to be elevated also in depressed patients. Further analysis demonstrated that the elevation observed in the plasma concentrations of both, OEA and 2-AG, was associated to SSRI antidepressant therapy at the time of recruitment. Further clinical research is needed to understand whether SSRI-induced elevations in OEA levels contribute to the response to SSRI in depressed patients as described in preclinical models.