Quantification of anandamide and 2‐arachidonoylglycerol plasma levels to examine potential influences of tetrahydrocannabinol application on the endocannabinoid system in humans

Abstract

The effects of tetrahydrocannabinol (THC) and endogenous cannabinoids (endocannabinoids, ECs) are both mediated by activation of the cannabinoid receptors CB1 and CB2. Exogenous activation of these receptors by THC could therefore alter EC levels. We tested this hypothesis in healthy volunteers (n = 25) who received a large intravenous dose of THC (0.10 mg/kg). Effects on the EC system were quantified by serial measurements of plasma ECs after THC administration. Eleven blood samples were drawn during the first 5 h after THC administration and two more samples after 24 and 48 h. THC, its metabolites THC-OH (biologically active) and THC-COOH (non-active), and the ECs anandamide and 2-arachidonoylglycerol (2-AG) were quantified by liquid chromatography-mass spectrometry. EC-plasma levels showed a biphasic response after THC injection reaching maximal values at 30 min. Anandamide increased slightly from 0.58 ± 0.21 ng/ml at baseline to 0.64 ± 0.24 ng/ml (p < 0.05) and 2-AG from 7.60 ± 4.30 ng/ml to 9.50 ± 5.90 ng/ml (p < 0.05). After reaching maximal concentrations, EC plasma levels decreased markedly to a nadir of 300 min after THC administration (to 0.32 ± 0.15 ng/ml for anandamide and to 5.50 ± 3.01 ng/ml for 2-AG, p < 0.05). EC plasma concentrations returned to near baseline levels until 48 h after the experiment. THC (0.76 ± 0.16 ng/ml) and THC-OH (0.36 ± 0.17 ng/ml) were still measurable at 24 h and remained detectible until 48 h after THC administration. Although the underlying mechanism is not clear, high doses of intravenous THC appear to influence endogenous cannabinoid concentrations and presumably EC-signalling.

Changing the tone of clinical study design in the cannabis industry

“…Thus, a circadian pattern in endocannabinoid signaling with a maximum in the morning and minimum in the evening was shown [18], whereas another study of healthy volunteers administered THC intravenously did not exhibit a circadian rhythm [24]. This may be attributed to the study design, since the former study included healthy volunteers who self-reported habitual sleep duration of 7.5 to 8.5 hours [18], whereas this was not accounted for in the latter study [24]. The diurnal nature of endocannabinoids and its impact on medicinal and nutritional interventions may have been overlooked within this paradigm, leading to challenges in making efficacy conclusions.…”

“…The endogenous circadian rhythm consists of the master/server clock seated in the SCN and the subordinate/client clock which is embedded in nearly every cell in the form of interlocking transcriptional-translational negative-feedback loops made up of Clock genes that exert their biological effects via Clock-controlled genes [10]. At the genetic level, heterodimerization of brain and muscle Arnt-like 1 (BMAL1) with Clock or neuronal PAS domain protein 2 (NPAS2) activates the translation of the PER and CRY dosing [24]. The augmented levels of endocannabinoids may be mediated by enhanced catecholinergic and glucocorticoid signaling, a direct pharmacologic effect of THC on endocannabinoid synthesis, or degradation.…”

Endocannabinoidomics: “Omics” Approaches Applied to Endocannabinoids and Endocannabinoid-Like Mediators

“…In particular, Zoerner et al reported a sensitive UPLC/MS/MS method to quantify AEA, 2-AG, and 1-AG in human blood samples, using toluene extraction to avoid matrix-effects, 2-AG/1-AG isomerization and degradation [40]. In this case, samples were extracted with ethyl acetate and cyclohexane, in the presence of deuterated internal standards, and analyzed by a triple quadrupole LC/MS/MS [50]. In this case, samples were extracted with ethyl acetate and cyclohexane, in the presence of deuterated internal standards, and analyzed by a triple quadrupole LC/MS/MS [50].…”

Oxidative Metabolites of Endocannabinoids Formed by Cyclooxygenase-2

“…Indeed, multiple reports have been published describing the analytical methodology in significant detail [20][21][22]. Indeed, multiple reports have been published describing the analytical methodology in significant detail [20][21][22].…”