LC-MS/MS quantification of Δ8-THC, Δ9-THC, THCV ISOMERS and their main metabolites in human plasma.

BACKGROUND: In recent years, potential therapeutic applications of several different cannabinoids, such as Δ9-tetrahydrocannabinol (Δ9-THC), its isomer Δ8-THC and Δ9-tetrahydrocannabivarin (Δ9-THCV), have been investigated. Nevertheless, to establish dose-effect relationship and to gain knowledge of their pharmacokinetics and metabolism, sensitive and specific analytical assays are needed to measure these compounds in patients. For this reason, we developed and validated an online extraction high-performance liquid chromatography- tandem mass spectrometry (LC/LC-MS/MS) method for the simultaneous quantification of 13 cannabinoids and metabolites including the Δ8 and Δ9 isomers of THC, THCV and those of their major metabolites in human plasma. METHODS: Plasma was fortified with cannabinoids at varying concentrations within the working range of the respective compound and 200 µL were extracted using a simple one-step protein precipitation procedure. The extracts were analyzed using online trapping LC/LC-atmospheric pressure chemical ionization (APCI)-MS/MS running in the positive multiple reaction monitoring (MRM) mode. RESULTS: The lower limit of quantification ranged from 0.5 to 2.5 ng/mL and the upper limit of quantification was 400 ng/mL for all analytes. Inter-day analytical accuracy and imprecision ranged from 82.9 to 109% and 4.3 to 20.3% (coefficient of variance), respectively. Of 534 plasma samples following controlled oral administration of Δ8-THCV, 236 were positive for Δ8-THCV (median; interquartile ranges: 3.5 ng/mL; 1.8 - 11.9 ng/mL), 383 for the major metabolite (-)-11-nor-9-carboxy-Δ8-tetrahydrocannabivarin (Δ8-THCV-COOH) (95.4 ng/mL; 20.7 - 328 ng/mL), 260 for (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabivarin (Δ9-THCV-COOH) (5.8 ng/mL; 2.5 - 16.1 ng/mL), 157 for (-)-11-hydroxy-Δ8-tetrahydrocannabivarin (11-OH-Δ8-THCV) (1.7 ng/mL; 1.0 - 3.7 ng/mL), 49 for Δ8-THC-COOH (1.7 ng/mL; 1.4 - 2.3 ng/mL) and 42 for Δ9-THCV (1.3 ng/mL; 0.8 - 1.6 ng/mL). CONCLUSIONS: We developed and validated the first LC/LC-MS/MS assay for the specific quantification of Δ8-THC, Δ9-THC and THCV isomers and their respective metabolites in human plasma. Δ8-THCV-COOH, 11-hydroxy-Δ8-THCV and Δ9-THCV-COOH were the major Δ8-THCV metabolites in human plasma after oral administration of 98.6% pure Δ8-THCV.

The Effects of Fingolimod (FTY720) on Leukocyte Subset Circulation cannot be Behaviourally Conditioned in Rats.

Suppression of immune functions can be elicited by behavioural conditioning using drugs such as cyclosporin A or rapamycin. Nevertheless, little is known about the underlying mechanisms and generalisability of this phenomenon. Against this background, the present study investigated whether the pharmacological properties of fingolimod (FTY720), an immunosuppressive drug widely applied to treat multiple sclerosis, can be conditioned in rats by means of taste-immune associative learning. For this purpose, a conditioned taste avoidance paradigm was used, pairing the presentation of a novel sweet drinking solution (saccharin or sucrose) as conditioned stimulus (CS) with therapeutically effective doses of FTY720 as unconditioned stimulus (US). Subsequent re-exposure to the CS at a later time point revealed that conditioning with FTY720 induced a mild conditioned taste avoidance only when saccharin was employed as CS. However, on an immunological level, neither re-exposure with saccharin nor sucrose altered blood immune cell subsets or splenic cytokine production. Despite the fact that intraperitonally administered FTY720 could be detected in brain regions known to mediate neuro-immune interactions, the present findings show that the physiological action of FTY720 is not inducible by mere taste-immune associative learning. Whether conditioning generalises across all small-molecule drugs with immunosuppressive properties still needs to be investigated with modified paradigms probably using distinct sensory CS. Moreover, these findings emphasize the need to further investigate the underlying mechanisms of conditioned immunomodulation to assess the generalisability and usability of associative learning protocols as supportive therapies in clinical contexts.

ACAD9 treatment with bezafibrate and nicotinamide riboside temporarily stabilizes cardiomyopathy and lactic acidosis.

Pathogenic ACAD9 variants cause complex I deficiency. Patients presenting in infancy unresponsive to riboflavin have high mortality. A six-month-old infant presented with riboflavin unresponsive lactic acidosis and life-threatening cardiomyopathy. Treatment with high dose bezafibrate and nicotinamide riboside resulted in marked clinical improvement including reduced lactate and NT-pro-brain type natriuretic peptide levels, with stabilized echocardiographic measures. After a long stable period, the child succumbed from cardiac failure with infection at 10.5 months. Therapy was well tolerated. Peak bezafibrate levels exceeded its EC50. The clinical improvement with this treatment illustrates its potential, but weak PPAR agonist activity of bezafibrate limited its efficacy.

Vaporized D-limonene selectively mitigates the acute anxiogenic effects of Δ9-tetrahydrocannabinol in healthy adults who intermittently use cannabis.

BACKGROUND: Cannabis contains hundreds of chemical constituents beyond delta-9-tetrahydrocannabinol (THC), which is believed to drive most of its acute pharmacodynamic effects. The entourage effect theory asserts that non-THC constituents can impact acute cannabis effects, but few empirical studies have systematically evaluated this theory in humans. This study assessed whether the cannabis terpenoid d-limonene mitigates the acute anxiogenic effects of THC. METHODS: Twenty healthy adults completed nine, double-blind outpatient sessions in which they inhaled vaporized THC alone (15mg or 30mg), d-limonene alone (1mg or 5mg), the same doses of THC and d-limonene together, or placebo; a subset of participants (n=12) completed a tenth session in which 30mg THC+15mg d-limonene was administered. Outcomes included subjective drug effects, cognitive/psychomotor performance, vital signs, and plasma THC and d-limonene concentrations. RESULTS: When d-limonene was administered alone, pharmacodynamic outcomes did not differ from placebo. Administration of 15mg and 30mg THC alone produced subjective, cognitive, and physiological effects typical of acute cannabis exposure. Ratings of anxiety-like subjective effects qualitatively decreased as d-limonene dose increased and concurrent administration of 30mg THC+15mg d-limonene significantly reduced ratings of "anxious/nervous" and "paranoid" compared with 30mg THC alone. Other pharmacodynamic effects were unchanged by d-limonene. D-limonene plasma concentrations were dose orderly, and concurrent administration of d-limonene did not alter THC pharmacokinetics. CONCLUSIONS: D-limonene selectively attenuated THC-induced anxiogenic effects, suggesting this terpenoid could increase the therapeutic index of THC. Future research should determine whether this effect extends to oral dose formulations and evaluate the interactions between other cannabis terpenoids or cannabinoids and THC.

Design and use of an ex vivo peripheral simulating bioreactor system for pharmacokinetic analysis of a drug coated stent.

Currently, there are no ex vivo systems that can model the motion of peripheral arteries and allow for the evaluation of pharmacokinetics (PK) of endovascular devices. The objective of this study was to develop a novel peripheral simulating bioreactor system to evaluate drug pharmacokinetics of stents. We utilized 3D-printed and off-the-shelf components to construct a peripheral-simulating bioreactor system capable of mimicking the motion of peripheral arteries. Servo motors were primarily used to shorten/elongate, twist, and bend explanted porcine carotid arteries. To evaluate the pharmacokinetics in the bioreactor, drug-eluting stents were deployed within explanted arteries and subjected to vascular motion along with pulsatile flow conditions. Following 30 min and 24 h, the arteries were removed, and paclitaxel levels were measured. Scanning electron microscopy was also performed to evaluate the stent surface. Arterial paclitaxel levels of the stent-treated arteries were found to be higher at 30 min than at 24 h following pulsatile and no vascular motion and even higher at 24 h following pulsatile flow and vascular motion. The residual drug on the stent significantly decreased from 30 min to 24 h. Scanning electron microscopy confirmed the loss of paclitaxel coating at 24 h and greater disturbance in stents under peripheral motion versus pulsatile only. This system represents the first ex vivo system to determine the PK of drug-eluting stents under physiological flow and vascular motion conditions. This work provides a novel system for a quick and inexpensive preclinical tool to study acute drug tissue concentration kinetics of drug-releasing interventional vascular devices designed for peripheral applications.

Minimum Effective Dose of Clemastine in a Mouse Model of Preterm White Matter Injury.

Background: Preterm white matter injury (PWMI) is the most common cause of brain injury in premature neonates. PWMI involves a differentiation arrest of oligodendrocytes, the myelinating cells of the central nervous system. Clemastine was previously shown to induce oligodendrocyte differentiation and myelination in mouse models of PWMI at a dose of 10 mg/kg/day. The minimum effective dose (MED) of clemastine is unknown. Identification if the MED is essential for maximizing safety and efficacy in neonatal clinical trials. We hypothesized that the MED in neonatal mice is lower than 10 mg/kg/day. Methods: Mouse pups were exposed to normoxia or hypoxia (10% FiO 2 ) from postnatal day 3 (P3) through P10. Vehicle or clemastine fumarate at one of four doses (0.5, 2, 7.5 or 10 mg/kg/day) was given orally to hypoxia-exposed pups. At P14, myelination was assessed by immunohistochemistry and electron microscopy to determine the MED. Clemastine pharmacokinetics were evaluated at steady-state on day 8 of treatment. Results: Clemastine rescued hypoxia-induced hypomyelination with a MED of 7.5 mg/kg/day. Pharmacokinetic analysis of the MED revealed C max 44.0 ng/mL, t 1/2 4.6 hours, and AUC 24 280.1 ng*hr/mL. Conclusion: Based on these results, myelination-promoting exposures should be achievable with oral doses of clemastine in neonates with PWMI. Key Points: Preterm white matter injury (PWMI) is the most common cause of brain injury and cerebral palsy in premature neonates.Clemastine, an FDA-approved antihistamine, was recently identified to strongly promote myelination in a mouse model of PWMI and is a possible treatment.The minimum effective dose in neonatal rodents is unknown and is critical for guiding dose selection and balancing efficacy with toxicity in future clinical trials.We identified the minimum effective dose of clemastine and the associated pharmacokinetics in a murine chronic hypoxia model of PWMI, paving the way for a future clinical trial in human neonates.

ß-Caryophyllene Inhibits Monoacylglycerol Lipase Activity and Increases 2-Arachidonoyl Glycerol Levels In Vivo: A New Mechanism of Endocannabinoid-Mediated Analgesia?

The mechanisms of ß-caryophyllene (BCP)-induced analgesia are not well studied. Here, we tested the efficacy of BCP in an acute postsurgical pain model and evaluated its effect on the endocannabinoid system. Rats were treated with vehicle and 10, 25, 50, and 75 mg/kg BCP. Paw withdrawal responses to mechanical stimuli were evaluated using an electronic von Frey anesthesiometer. Endocannabinoids, including 2-arachidonoylglycerol (2-AG), were also evaluated in plasma and tissues using high-performance liquid chromatography-tandem mass spectrometry. Monoacylglycerol lipase (MAGL) activity was evaluated in vitro as well as ex vivo. We observed a dose-dependent and time-dependent alleviation of hyperalgesia in incised paws up to 85% of the baseline value at 30 minutes after administration of BCP. We also observed dose-dependent increases in the 2-AG levels of about threefold after administration of BCP as compared with vehicle controls. Incubations of spinal cord tissue homogenates from BCP-treated rats with isotope-labeled 2-arachidonoylglycerol-d8 revealed a reduced formation of the isotope-labeled MAGL product 2-AG-d8 as compared with vehicle controls, indicating MAGL enzyme inhibition. In vitro MAGL enzyme activity assessment using 2-AG as the substrate revealed an IC50 of 15.8 µM for MAGL inhibition using BCP. These data showed that BCP inhibits MAGL activity in vitro and in vivo, causing 2-AG levels to rise. Since the endocannabinoid 2-AG is a CB1 and CB2 receptor agonist, we propose that 2-AG-mediated cannabinoid receptor activation contributes to BCP's mechanism of analgesia. SIGNIFICANCE STATEMENT: ß-Caryophyllene (BCP) consumption is relatively safe and is approved by the Food and Drug Administration as a flavoring agent, which can be used in cosmetic and food additives. BCP is a potent anti-inflammatory agent that showed substantial antihyperalgesic properties in this study of acute pain suggesting that BCP might be an alternative to opioids. This study shows an additive mechanism (monoacylglycerol lipase inhibition) by which BCP might indirectly alter CB1 and CB2 receptor activity and exhibit its pharmacological properties.

Structural Identification of Zotarolimus (ABT-578) Metabolites Generated by Human Liver Microsomes Using Ion-Trap and High-Resolution Time-of-Flight Mass Spectrometry in Combination with the Analysis of Fragmentation Patterns.

Zotarolimus (ABT-578) is a sirolimus derivative that, like sirolimus and everolimus, is an inhibitor of cell growth via inhibition of the mechanistic target of rapamycin (mTOR). Zotarolimus was developed for coating coronary stents to prevent smooth muscle cell proliferation and restenosis. Albeit zotarolimus-eluting cardiovascular devices have been on the market for years, details of zotarolimus drug metabolism in humans are still unknown. Hence, it was the goal of the present study to identify zotarolimus metabolites generated by incubation with human liver microsomes. Metabolite structures were identified using high-resolution mass spectrometry, MS/ion-trap (MSn), and comparison of fragmentation patterns of the metabolites with those of zotarolimus and other known sirolimus derivatives. Kinetic parameters such as incubation time, human liver microsomal protein concentrations, and drug concentrations were optimized before scaling up the metabolism experiments. Human liver microsomes mainly hydroxylated and/or demethylated zotarolimus. The structures of the following metabolites were identified: O-demethylated metabolites: 39-O-desmethyl, 16-O-desmethyl, and 27-O-desmethyl zotarolimus; hydroxylated metabolites: hydroxy piperidine zotarolimus, 11-hydroxy, 12-hydroxy, 14-hydroxy, 23-hydroxy, 24-hydroxy, 25-hydroxy, 45/46-hydroxy, and 49-hydroxy zotarolimus; demethylated-hydroxylated metabolites: 16-O-desmethyl, 23/24-hydroxy; 39-O-desmethyl, 23/24-hydroxy; 39-O-desmethyl, 25-hydroxy zotarolimus; 39-O-desmethyl, 11-hydroxy zotarolimus; 39-O-desmethyl, hydroxy-piperidine zotarolimus; 27-O-desmethyl, 45/46-hydroxy zotarolimus; didemethylated metabolites: 16,39-O-didesmethyl zotarolimus; 16,27-O-didesmethyl zotarolimus; 27,39-O-didesmethyl zotarolimus; and dihydroxylated metabolites: 11,24-dihydroxy zotarolimus, 12,24-dihydroxy zotarolimus, and 11,47/48-dihydroxy zotarolimus. It is concluded that zotarolimus is extensively metabolized by human liver microsomes. Twenty-four of these metabolites could be structurally identified using a combination of ion-trap MSn and high-resolution mass spectrometry.

Sex differences in endocannabinoid tone in a pilot study of cannabis use disorder and acute cannabis abstinence.

Cannabis use disorder (CUD) presents differently in men and women, particularly in symptoms of cannabis withdrawal. Novel pharmacotherapeutic interventions for CUD, such as those that target the endocannabinoid (eCB) system, must be developed in a manner consistent with these sex differences. The present pilot study sought to prospectively assess sex differences in cannabis withdrawal in a small sample of adults with moderate-to-severe CUD and to determine if withdrawal was associated with peripheral eCB and eCB congener tone. Men and women (n = 5/sex) completed 2 weeks of study participation separated by 1 month; in the latter week, participants abstained from cannabis use. Each week, participants attended in-person laboratory visits during which blood was drawn repeatedly to assess plasma eCB and eCB congener tone. Participants also completed multiple daily ambulatory assessments to assess cannabis use and withdrawal symptoms. As anticipated, women reported a greater increase in withdrawal symptoms during the abstinent week [Δ = 9.4 (SE = 1.1); p < 0.001] than men [Δ = 1.2 (SE = 1.2); p = 0.35]. Sex differences in levels of the eCB N-arachidonoylethanolamide (AEA), as well as the eCB congeners stearoylethanolamide (SEA) and linoleylethanolamide (LEA), were evident during abstinence at the morning time point only (p's < 0.05). LEA was associated with withdrawal symptom expression in both sexes [ß = 0.16 (SE = 0.09)] and palmitoylethanolamide (PEA) [ß = 0.22 (SE = 0.13)] and 2-arachidonoylglycerol (2-AG) [ß = 0.32 (SE = 0.15)] were associated with withdrawal symptoms in women only. Pharmacotherapeutic development for CUD should consider evident sex differences in eCB and eCB congener tone during abstinence and their associations with cannabis withdrawal, as eCB-based interventions may produce differential effects by sex.

Interstage Single Ventricle Heart Disease Infants Show Dysregulation in Multiple Metabolic Pathways: Targeted Metabolomics Analysis.

BACKGROUND: Infants with SVHD experience morbidity related to pulmonary vascular inadequacy. Metabolomic analysis involves a systems biology approach to identifying novel biomarkers and pathways in complex diseases. The metabolome of infants with SVHD is not well understood and no prior study has evaluated the relationship between serum metabolite patterns and pulmonary vascular readiness for staged SVHD palliation. OBJECTIVES: The purpose of this study was to evaluate the circulating metabolome of interstage infants with single ventricle heart disease (SVHD) and determine whether metabolite levels were associated with pulmonary vascular inadequacy. METHODS: This was a prospective cohort study of 52 infants with SVHD undergoing Stage 2 palliation and 48 healthy infants. Targeted metabolomic phenotyping (175 metabolites) was performed by tandem mass spectrometry on SVHD pre-Stage 2, post-Stage 2, and control serum samples. Clinical variables were extracted from the medical record. RESULTS: Random forest analysis readily distinguished between cases and controls and preoperative and postoperative samples. Seventy-four of 175 metabolites differed between SVHD and controls. Twenty-seven of 39 metabolic pathways were altered including pentose phosphate and arginine metabolism. Seventy-one metabolites differed in SVHD patients between timepoints. Thirty-three of 39 pathways were altered postoperatively including arginine and tryptophan metabolism. We found trends toward increased preoperative methionine metabolites in patients with higher pulmonary vascular resistance and higher postoperative tryptophan metabolites in patients with greater postoperative hypoxemia. CONCLUSIONS: The circulating metabolome of interstage SVHD infants differs significantly from controls and is further disrupted after Stage 2. Several metabolites showed trends toward association with adverse outcomes. Metabolic dysregulation may be an important factor in early SVHD pathobiology.

Associations between Prenatal and Postnatal Exposure to Cannabis with Cognition and Behavior at Age 5 Years: The Healthy Start Study.

BACKGROUND: Prenatal exposure to cannabis may influence childhood cognition and behavior, but the epidemiologic evidence is mixed. Even less is known about the potential impact of secondhand exposure to cannabis during early childhood. OBJECTIVE: This study sought to assess whether prenatal and/or postnatal exposure to cannabis was associated with childhood cognition and behavior. STUDY DESIGN: This sub-study included a convenience sample of 81 mother-child pairs from a Colorado-based cohort. Seven common cannabinoids (including delta 9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD)) and their metabolites were measured in maternal urine collected mid-gestation and child urine collected at age 5 years. Prenatal and postnatal exposure to cannabis was dichotomized as exposed (detection of any cannabinoid) and not exposed. Generalized linear models examined the associations between prenatal or postnatal exposure to cannabis with the NIH Toolbox and Child Behavior Checklist T-scores at age 5 years. RESULTS: In this study, 7% (n = 6) of the children had prenatal exposure to cannabis and 12% (n = 10) had postnatal exposure to cannabis, with two children experiencing this exposure at both time points. The most common cannabinoid detected in pregnancy was Δ9-THC, whereas the most common cannabinoid detected in childhood was CBD. Postnatal exposure to cannabis was associated with more aggressive behavior (ß: 3.2; 95% CI: 0.5, 5.9), attention deficit/hyperactivity problems (ß: 8.0; 95% CI: 2.2, 13.7), and oppositional/defiant behaviors (ß: 3.2; 95% CI: 0.2, 6.3), as well as less cognitive flexibility (ß: -15.6; 95% CI: -30.0, -1.2) and weaker receptive language (ß: -9.7; 95% CI: -19.2, -0.3). By contrast, prenatal exposure to cannabis was associated with fewer internalizing behaviors (mean difference: -10.2; 95% CI: -20.3, -0.2) and fewer somatic complaints (mean difference: -5.2, 95% CI: -9.8, -0.6). CONCLUSIONS: Our study suggests that postnatal exposure to cannabis is associated with more behavioral and cognitive problems among 5-year-old children, independent of prenatal and postnatal exposure to tobacco. The potential risks of cannabis use (including smoking and vaping) during pregnancy and around young children should be more widely communicated to parents.

Effects of oral Δ9-tetrahydrocannabinol and cannabidiol combinations on a sustained attention task in rats.

A well-documented side effect of cannabis and Δ9-tetrahydrocannabinol (THC) acute administration is deficits in cognition and attention. Cannabidiol (CBD), a nonintoxicating constituent of cannabis, may modulate THC's impairing effects. A goal of this study was to determine the effects of THC and CBD, alone and in combination, on performance in the rodent Psychomotor Vigilance Test (rPVT), a translational paradigm used to quantify sustained attention. Outcome measures in the rPVT include motor speed, premature responding, and lapses in attention. Sprague Dawley rats were trained to perform the rPVT to the acquisition criteria and then received oral doses (mg/kg) of THC (1-17.6), CBD (1-100), and combinations of THC + CBD in sesame oil prior to rPVT sessions, administered in a within-subject randomized design. Blood was collected from rats receiving selected doses of THC alone or THC + CBD for analysis of THC and its metabolites. THC alone produced significant decreases in accuracy and increases in lapses in attention at higher doses (10 mg/kg; ps < .05). The coadministration of CBD (10 mg/kg) with THC (3 or 10 mg/kg) caused greater impairments to sustained attention compared with administration of THC alone (ps < .05). The rPVT is a translational platform sensitive to detect impairments in attention associated with THC and other cannabis constituents. Further work is necessary to determine the mechanism of THC and CBD interactions on impairments in sustained attention. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Lidocaine Intraoperative Infusion Pharmacokinetics during Partial Hepatectomy for Living Liver Donation.

BACKGROUND: Postoperative pain associated with open partial hepatectomy can be intense and persistent. The multimodal approach used to lessen this problem includes an intraoperative intravenous infusion of lidocaine hydrochloride. Decreased hepatic metabolism after resection raises concerns about safe lidocaine dosing in this patient population. The hypothesis was that the elimination clearance of lidocaine and its metabolites, monoethylglycinexylidide and glycinexylidide, is reduced after a partial hepatectomy, as reflected by observed plasma concentrations that are higher and have a longer half-life than expected based on pharmacokinetic modeling (estimated for normal liver function). Secondarily, this study postulated that plasma concentrations of lidocaine, monoethylglycinexylidide, and glycinexylidide do not reach toxic concentrations with institutional protocol up to 24 h after surgery. METHODS: Blood samples were collected from 15 patients undergoing a partial hepatectomy for living liver donation, at the following specific time points: before and immediately after induction of anesthesia, during hepatectomy, 30 min after hepatectomy completion, at case end, and 24 h after the end of surgery. Plasma concentrations of lidocaine and metabolites were measured by liquid chromatography-mass spectrometry. The population lidocaine pharmacokinetics were estimated, and total body weight and the fraction of remaining liver mass as potential model covariates were evaluated. The detection of any lidocaine, monoethylglycinexylidide, or glycinexylidide toxic plasma concentrations at any time point during and after hepatectomy were also evaluated. RESULTS: The typical value for lidocaine elimination clearance was 0.55 ± 0.12 l/min (± standard error of the estimate) which, on average, was reduced to about one third of the baseline clearance, 0.17 ± 0.02 l/min, once the donor graft was surgically isolated, and remained so for 24 h according to the current data and model. The fraction of remaining liver was a significant covariate for the posthepatectomy lidocaine clearance' such that if 50% of the liver is removed the clearance is reduced by approximately 60%. Plasma concentrations of lidocaine and its metabolites remained below their theoretical combined toxic threshold concentrations throughout the surgical and postoperative course in all patients, with one exception obtained near induction of anesthesia. Plasma lidocaine concentrations decreased at case end and postoperatively, while metabolite concentrations continued to rise at the end of surgery with reduction postoperatively. Pharmacokinetic modeling revealed that the only significant covariate in the model was the fraction of liver remaining after isolation of the donor graft. CONCLUSIONS: Intravenous lidocaine infusions are an acceptable option for multimodal pain management in patients undergoing a hepatectomy for living donation if the lidocaine infusion is stopped when the liver resection is complete. Clearance of lidocaine is decreased proportionally to the remaining liver mass, which should guide lidocaine infusion administration or dosing adjustments for patients undergoing liver resection surgery.

Kynurenines in polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disorder, characterized by kidney cyst formation. A major pathological feature of ADPKD is the development of interstitial inflammation. Due to its role in inflammation and oxidative stress, tryptophan metabolism and related kynurenines may have relevance in ADPKD. METHODS: Data were collected from a well-characterized longitudinal cohort of pediatric and adult patients with ADPKD and compared to age-matched healthy subjects. To evaluate the role of kynurenines in ADPKD severity and progression, we investigated their association with height-corrected total kidney volume (HtTKV) and kidney function (estimated glomerular filtration rate (eGFR)). Key tryptophan metabolites were measured in plasma using a validated liquid chromatography-mass spectrometry assay. RESULTS: There was a significant accumulation of kynurenine and kynurenic acid (KYNA) in children and adults with ADPKD as compared to healthy subjects. Downstream kynurenines continued to accumulate in adults with ADPKD concurrent with the increase of inflammatory markers IL-6 and MCP-1. Both markers remained unchanged in ADPKD as compared to healthy children, suggesting alternate pathways responsible for the observed rise in kynurenine and KYNA. KYNA and kynurenine/tryptophan positively associated with disease severity (HtTKV or eGFR) in patients with ADPKD. After Bonferroni adjustment, baseline kynurenines did not associate with disease progression (yearly %change in HtTKV or yearly change in eGFR) in this limited number of patients with ADPKD. CONCLUSION: Kynurenine metabolism seems dysregulated in ADPKD as compared to healthy subjects. Inhibition of kynurenine production by inhibition of main pathway enzymes could present a novel way to reduce the progression of ADPKD.

Maternal Plasma Choline during Gestation and Small for Gestational Age Infants.

OBJECTIVE: Small for gestational age (SGA) infants are at increased risk for neonatal morbidity and developmental problems in childhood. No current interventions during human pregnancy address this problem. This study investigated the possible relationship between maternal choline concentration during pregnancy and SGA infants. STUDY DESIGN: Maternal plasma choline concentrations were sampled at 16 and 28 weeks' gestation from women in a public prenatal clinic. Additional factors assessed were maternal age, body mass index, infection, C-reactive protein, hair cortisol, and compliance with prenatal vitamins and folate. Infants below the 10th percentile for gestational age were classified as SGA. Binary logistic regression was used to identify significant associated factors in pregnancies resulting in SGA infants compared with pregnancies resulting in non-SGA infants. RESULTS: Thirteen (8%) of 159 women had SGA infants. Maternal plasma choline concentrations were low for pregnant participants whose infants were SGA, with the 28-week concentration significantly lower compared with other participants. Plasma choline concentrations ≥7 µM at 28 weeks, consistent with a minimally adequate dietary intake of choline-containing foods, were achieved by only 2 (15%) of mothers with SGA infants, compared with 51% of mothers whose infants were not SGA. Choline concentrations <7 µM at 28 weeks' gestation were associated with an odds ratio for SGA of 16.6 (95% confidence interval: 1.5-189.2, p = 0.023). Other significant factors were female sex and maternal C-reactive protein plasma concentration during gestation. CONCLUSION: This observational study suggests that higher maternal choline levels may influence the risk for SGA. Maternal plasma choline concentrations are not routinely available in clinical laboratories. However, plasma choline levels can be increased by the mothers' intake of choline or phosphatidylcholine supplements. No nutritional intervention is currently recommended to prevent SGA, but the evidence from this study suggests that further consideration of the role of maternal choline may be warranted. KEY POINTS: · More females are small for gestational age.. · Low maternal choline is related to small infants.. · Maternal choline ≥7 µM at 28 weeks appears optimal..

Effects of tofacitinib therapy on arginine and methionine metabolites in association with vascular pathophysiology in rheumatoid arthritis: A metabolomic approach.

Introduction: Rheumatoid arthritis (RA) has been associated with changes in lipid, arginine and NO metabolism with increased cardiovascular (CV) risk. The aim of this study is to evaluate the effect of tofacitinib, a Janus kinase (JAK) inhibitor, on arginine and methionine metabolism in correlation with inflammation, functional and pathological vascular changes during one-year treatment of patients with RA. Materials and methods: Thirty RA patients with active disease were treated with either 5 mg bid or 10 mg bid tofacitinib for 12 months. We determined DAS28, CRP, IgM rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) levels. We assessed brachial artery flow-mediated vasodilation (FMD), carotid intima-media thickness (IMT) and pulse-wave velocity (PWV) by ultrasound at baseline and after 6 and 12 months. We also determined plasma L-arginine, L-citrulline, L-ornithine, inducible nitric oxide synthase (iNOS), asymmetric (ADMA) and symmetric dimethylarginine (SDMA), L-N-monomethyl-arginine (L-NMMA), cysteine, homocysteine, and methionine levels at these time points. Results: Twenty-six patients (13 on each arm) completed the study. CRP, ESR and DAS28 decreased significantly during one-year treatment with tofacitinib. Arginine and ADMA showed a negative univariate correlation with CRP but not with FMD, PWV or IMT. Tofacitinib at 10 mg bid significantly increased L-arginine, L-ornithine, iNOS and methionine levels after 12 months. ADMA and SDMA levels did not change in our study. Methionine showed negative correlation with FMD at baseline and positive correlation with PWV after 12 months. No change was observed in FMD and PWV but a significant increase was measured in IMT at 6 and 12 months. Multivariate analysis indicated variable correlations of L-arginine, L-citrulline, ADMA, L-NMMA, homocysteine and methionine with DAS28, CRP, ESR and RF but not with anti-CCP after one-year treatment. With respect to vascular pathophysiology, only PWV and methionine correlated with each other. Conclusion: One-year tofacitinib treatment suppressed systemic inflammation and improved functional status in RA. FMD, PWV have not been affected by one-year tofacitinib treatment., while IMT increased further despite treatment. Increased arginine and methionine might contribute to the anti-inflammatory effects of tofacitinib. Increased arginine availability with no changing ADMA may protect FMD and PWV from deterioration. The increase of IMT in the anti-inflammatory environment cannot be explained by arginine or methionine metabolism in this study.

Δ9-Tetrahydrocannabinol Vapor Exposure Produces Conditioned Place Preference in Male and Female Rats.

Background: The use of place conditioning procedures and drug vapor exposure models can increase our understanding of the rewarding and aversive effects of vaped cannabis products. Currently there are limited data on the conditioned rewarding effects of vaporized Δ9-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis in rats, and no studies to date examining sex differences. Methods: Male and female Sprague-Dawley rats (N=96; 12 per sex/group) underwent place conditioning sessions immediately after exposure to THC or vehicle (propylene glycol [PG]) vapor. Locomotor activity was measured by beam breaks during conditioning sessions. THC vapor-conditioned rats received one of three THC vapor exposure amounts (low: 5 puffs of 100 mg/mL THC, medium: 5 puffs of 200 mg/mL THC, or high: 10 puffs of 200 mg/mL THC) and matched vehicle vapor (PG) exposure on alternate days for 16 daily sessions. A "no THC" control group of vehicle-conditioned rats received only PG vapor exposure each day. After the 8th and 16th conditioning sessions, untreated rats were tested for conditioned place preference (CPP) or aversion (CPA). Next, extinction tests and a THC vapor-primed reinstatement test were conducted. Results: THC vapor produced CPP and locomotor effects in an exposure dependent manner, and some sex differences were observed. Low THC vapor exposure did not produce CPP in males or females. Medium THC vapor exposure produced CPP in males, but not females. High THC vapor exposure produced CPP in both males and females. Medium and high THC vapor exposure amounts produced hyperactivity in female rats, but not male rats. CPP was more resistant to extinction in females than males. THC vapor reexposure (i.e., drug-prime) after extinction did not result in reinstatement of CPP for either sex. Conclusion: This study demonstrates conditioned rewarding effects of THC vapor in both male and female rats and provides evidence for sex differences in amounts of THC vapor that produce CPP and in time to extinction. CPA was not observed at any of the THC vapor exposure amounts tested. These data provide a foundation for future exploration of the conditioned effects of cannabis constituents and extracts using vapor exposure models.

Endocannabinoid System in Polycystic Kidney Disease.

INTRODUCTION: Autosomal dominant polycystic kidney disease (ADPKD) is a commonly inherited disorder characterized by renal cyst formation. A major pathological feature of ADPKD is the development of interstitial inflammation. The endocannabinoid (EC) system is present in the kidney and has recently emerged as an important player in inflammation and the pathogenesis of progressive kidney disease. METHODS: Data on ECs were collected using a validated mass spectrometry assay from a well-characterized cohort of 102 ADPKD patients (at baseline and after 2- and 4 years on standard vs. rigorous blood-pressure control) and compared to 100 healthy subjects. RESULTS: Compared to healthy individuals, we found higher interleukins-6 and -1b as well as reduced plasma levels of anandamide (AEA), 2-arachidonoyl-glycerol (2-AG), and their congeners in ADPKD patients. Baseline AEA concentration negatively associated with the progression of ADPKD as expressed by the yearly percent change in height-corrected total kidney volume and positively with the yearly change in renal function (measured as estimated glomerular filtration rate, ΔeGFR). AEA analog palmitoylethanolamide (PEA) is also associated positively with the yearly change in eGFR. DISCUSSION AND CONCLUSION: The results of the present study suggest that ADPKD patients present with lower levels of ECs and that reestablishing the normality of the renal EC system via augmentation of AEA, PEA, and 2-AG levels, either through the increase of their synthesis or through a reduction of their degradation, could be beneficial and may present a promising therapeutic target in said patients.

Urinary clearance of 11-nor-9-carboxy-Δ9 -tetrahydrocannabinol: A detailed pharmacokinetic analysis.

Urine is a common matrix for screening for cannabis use. Urine assays typically measure total 11-nor-9-carboxy-Δ9 -tetrahydrocannabinol (THCCOOH) concentrations after hydrolysis cleaves the glucuronide. Urine THCCOOH concentration is adjusted by urine creatinine concentration or specific gravity, to account for variable hydration states. Therefore, we performed a population pharmacokinetic analysis of the urinary THCCOOH excretion, urinary flow rate, and creatinine excretion rate data. Urine was obtained over 168 h from six subjects who smoked low- (15.8 mg) and high-dose (33.8 mg) Δ9 -tetrahydrocannabinol (THC) cigarettes on two occasions. Samples were analyzed for THCCOOH concentration by gas chromatography-mass spectrometry (GC-MS) and volume, time, and creatinine concentration measured. A population pharmacokinetic model of the urinary clearance of THCCOOH was created from these data, and potential covariates of urine creatinine concentration and urine creatinine excretion rate were assessed. Elimination clearance of THCCOOH was estimated as 0.104 ± 0.088 L/min, and its urinary clearance was 0.0022 ± 0.0015 L/min. Total urine excretion of THCCOOH was estimated at 2.3%. Urine flow rate and urine creatinine concentrations were significantly correlated, r2 = 0.35. Creatinine excretion rate was 129.6 ± 71.0 ml/min, and the intrasubject variability was 31%-52% (SD%) during the week. Urinary creatinine excretion rate was a significant covariate for the urinary clearance of THCCOOH. Creatinine clearance is a significant covariate for urinary THCCOOH clearance. Only 2%-3% of bioavailable THC is excreted as THCCOOH and THCCOO-glucuronide via the urine. Correction of urine drug and/or metabolite concentration with urine creatinine concentration or specific gravity may be more problematic than previously appreciated.