Biochemical and Biophysical Research Communications
Finding of endocannabinoids in human eye tissues: Implications for glaucoma☆
Section snippets
Materials and methods
Human eyes. Normal eyes (n = 12) or glaucomatous eyes (n = 12) of donors were obtained from the National Disease Research Interchange (Philadelphia, PA, USA) and the Central Florida Lions Eye and Tissue Bank (Tampa, FL, USA). The organ banks obtained informed consent from all donors or their family members. The mean donor age was 70.5 ± 2.6 years (range 49–90) for normal eyes and 76.0 ± 3.5 years (range 56–91) for glaucomatous eyes. The eyes were enucleated 2–10 h after death, stored in
Comparison of endocannabinoid levels in the different eye tissues
In human normal and glaucomatous eyes, 2-AG, PEA, and AEA were detected in all the tissues examined. The levels of individual substances varied between the ocular tissues and ranged as follows: 2-AG (range 62–1393 pmol/g tissue; Fig. 1), PEA (range 95–637 pmol/g tissue; Fig. 2), and AEA (range 24–178 pmol/g tissue; Fig. 3). 2-AG levels were higher in the human normal retina (1393 ± 213 pmol/g), ciliary body (503 ± 92 pmol/g), and choroid (493 ± 204 pmol/g) compared to the iris (118 ± 21 pmol/g) and cornea (65 ±
Discussion
Glaucoma is a group of progressive optic neuropathies characterized by degeneration of retinal ganglion cells and their axons, with resultant visual field defects and loss of vision [23], [24], [25], [26]. This ocular disease is the second leading cause of blindness worldwide and patients are usually asymptomatic until late in the course of the disease [23], [24], [25]. Elevated IOP and large diurnal IOP fluctuations are well-understood risk factors for the development of glaucoma and
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2023, Journal of Photochemistry and PhotobiologyCitation Excerpt :The presence of ECS elements has been demonstrated in the ocular tissue of different species, from fish to primates [154–157]. The level of 2-AG was found to be significantly higher than that of AEA in human and bovine retinas [90,158]. DAGL and MAGL expression was observed in rat and mouse retinas, which are the main enzymes responsible for the synthesis and hydrolysis of 2-AG [159–161].
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2021, Journal of Psychiatric ResearchCitation Excerpt :The current scientific data make it difficult to differentiate between the selective expression of CB1 and CB2 receptors on the On or Off cone pathways. The CB1 and CB2 receptors are stimulated primarily by two endogenous ligands: 2-AG, which is present in the human retina at significant concentrations, and anandamide, which is present at lower concentrations (Chen et al., 2005; Devane et al., 1992; Mechoulam and Parker, 2013; Stamer et al., 2001). The most important enzymes in regulating the concentration of these ligands are diacylglycerol lipase alpha and beta (DAGLα and DAGLβ) (Bisogno et al., 2003), N-acyl-phosphatidylethanolamine-phospholipase D (NAPE-PLD) (Di Marzo et al., 1994; Pertwee et al., 2010), cyclooxygenase 2 (COX-2) (Yazulla, 2008), fatty acid amide hydrolase (FAAH) (Pertwee, 2005) and monoacylglycerol lipase (MGL) (Pertwee, 2005).
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Abbreviations: AEA, anandamide, N-arachidonoylethanolamine; 2-AG, 2-arachidonoylglycerol; CB, cannabinoid; FAAH, fatty acid amide hydrolase; IOP, intraocular pressure; LC-APCI-MS, liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry; NAAA, N-acylethanolamine-hydrolyzing acid amidase; NAPE-PLD, N-acyl-phosphatidylethanolamine-hydrolyzing phospholipase D; MAGL; monoacylglycerol lipase; PEA, palmitoylethanolamide; POAG, primary open-angle glaucoma; PLC, phospholipase C; PLA2, phospholipase A2; TRPV1, transient receptor potential vanilloid type 1.