Circulating Endocannabinoids: From Whence Do They Come and Where are They Going?

Abstract

The goal of this review is to summarize studies in which concentrations of circulating endocannabinoids in humans have been examined in relationship to physiological measurements and pathological status. The roles of endocannabinoids in the regulation of energy intake and storage have been well studied and the data obtained consistently support the hypothesis that endocannabinoid signaling is associated with increased consumption and storage of energy. Physical exercise mobilizes endocannabinoids, which could contribute to refilling of energy stores and also to the analgesic and mood-elevating effects of exercise. Circulating concentrations of 2-arachidonoylglycerol are very significantly circadian and dysregulated when sleep is disrupted. Other conditions under which circulating endocannabinoids are altered include inflammation and pain. A second important role for endocannabinoid signaling is to restore homeostasis following stress. Circulating endocannabinoids are stress-responsive and there is evidence that their concentrations are altered in disorders associated with excessive stress, including post-traumatic stress disorder. Although determination of circulating endocannabinoids can provide important information about the state of endocannabinoid signaling and thus allow for hypotheses to be defined and tested, the large number of physiological factors that contribute to their circulating concentrations makes it difficult to use them in isolation as a biomarker for a specific disorder.

In silico interaction analysis of cannabinoid receptor interacting protein 1b (CRIP1b) – CB1 cannabinoid receptor

“…The two cannabinoid receptors, the CB 1 receptor and the CB 2 receptor, have been identified including multiple splice variants of CB 1 in humans [1, 2]. The CB 1 receptor is predominantly expressed in brain where it seems to play an important role in regulating analgesia, appetite, obesity, learning and memory, synaptic plasticity, substance abuse disorders, and neuro-protection [1, 3–5]. TheCB 2 receptor, in contrast is found primarily in peripheral tissue, including tissue associated with immune system like spleen and tonsils, and is involved in cannabinoid mediated immune response[1,2].…”

“…TheCB 2 receptor, in contrast is found primarily in peripheral tissue, including tissue associated with immune system like spleen and tonsils, and is involved in cannabinoid mediated immune response[1,2]. Cannabinoid receptors bind and are activated by the lipid derived endocannabinoid ligands, anandamide and 2-arachidonoylglycerol[3,4]. CB 1 receptor signaling and regulation have assumed increased biomedical significance because of their involvement in variety of physiological disorders and diseases [3–5].…”

“…Cannabinoid receptors bind and are activated by the lipid derived endocannabinoid ligands, anandamide and 2-arachidonoylglycerol[3,4]. CB 1 receptor signaling and regulation have assumed increased biomedical significance because of their involvement in variety of physiological disorders and diseases [3–5]. …”

Endocannabinoids and Related Lipids in Chronic Pain: Analytical and Clinical Aspects

“…However, since age also increases the risk of developing FM [197], such corrections could be disputed. BMI and circulating 2-AG seems to be positively correlated [187], which was found in paper IV as well. Activating of CB 1 increases food intake, and the hunger inhibiting hormone leptin decreases hypothalamic EC levels [198].…”

“…In contrast to the NAEs, which were measured in both muscles and plasma in patients and controls, 2-AG was measured only in plasma. Hence we can only speculate about its origin, which could be various tissues and organs, circulation cells, and brain [187]. If 2-AG reflects the pathology of FM (or different aspect), it could be related to different signs of its manifestations.…”