Changes in endocannabinoid and palmitoylethanolamide levels in eye tissues of patients with diabetic retinopathy and age-related macular degeneration.
Cannabinoid receptors and the endocannabinoids (anandamide (N-arachidonoylethanolamine--AEA) and 2-arachidonoylglycerol (2-AG)), as well as the AEA congener, palmitoylethanolamide (PEA), are involved in ocular physiology. We measured endocannabinoid and PEA levels by isotope-dilution liquid chromatography-mass spectrometric analysis in post-mortem eye tissues of patients with diabetic retinopathy (DR) or age-related macular degeneration (AMD). In eyes with DR, significantly enhanced levels of AEA were found in the retina ( approximately 1.8-fold), ciliary body ( approximately 1.5-fold) and, to a lesser extent, cornea ( approximately 1.3-fold). Surprisingly, 2-AG levels were significantly higher ( approximately 3-fold) only in the iris, whereas PEA levels only slightly increased ( approximately 1.3-fold) in the ciliary body. In eyes with AMD, significantly enhanced levels of AEA were found in the choroid ( approximately 1.3-fold), ciliary body ( approximately 1.4-fold) and cornea ( approximately 1.4-fold), whereas in the retina only a trend towards an increase ( approximately 1.5-fold) was observed. The tissue- and disease-selective nature of the changes observed suggests that the compounds analyzed here may play different roles in the control of eye function under different pathological conditions.
Matias
I
I
Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Via Toiano 6, 80072 Arco Felice, Pozzuoli (Napoli), Italy.
Wang
J W
JW
Moriello
A Schiano
AS
Nieves
A
A
Woodward
D F
DF
Di Marzo
V
V
D000577:Amides; D001095:Arachidonic Acids / Q000032:analysis*; D063385:Cannabinoid Receptor Modulators / Q000032:analysis; D003930:Diabetic Retinopathy / Q000378:metabolism*; D063388:Endocannabinoids; D004983:Ethanolamines; D005123:Eye / Q000737:chemistry*; D005989:Glycerides / Q000032:analysis*; D006801:Humans; D008268:Macular Degeneration / Q000378:metabolism*; D010169:Palmitic Acids / Q000032:analysis*; D053284:Polyunsaturated Alkamides / Q000032:analysis*; D015854:Up-Regulation
D000577:Amides; D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D004983:Ethanolamines; D005989:Glycerides; D010169:Palmitic Acids; D053284:Polyunsaturated Alkamides; C005958:palmidrol; C094503:glyceryl 2-arachidonate; C078814:anandamide