title: Involvement of the endocannabinoid system in the physiological response to transient common carotid artery occlusion and reperfusion.
abstract: BACKGROUND
  The transient global cerebral hypoperfusion/reperfusion achieved by induction of Bilateral Common Carotid Artery Occlusion followed by Reperfusion (BCCAO/R) may trigger a physiological response in an attempt to preserve tissue and function integrity. There are several candidate molecules among which the endocannabinoid system (ECS) and/or peroxisome-proliferator activated receptor-alpha (PPAR-alpha) may play a role in modulating oxidative stress and inflammation. The aims of the present study are to evaluate whether the ECS, the enzyme cyclooxygenase-2 (COX-2) and PPAR-alpha are involved during BCCAO/R in rat brain, and to identify possible markers of the ongoing BCCAO/R-induced challenge in plasma.
  
  
  METHODS
  Adult Wistar rats underwent BCCAO/R with 30 min hypoperfusion followed by 60 min reperfusion. The frontal and temporal-occipital cortices and plasma were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS) to determine concentrations of endocannabinoids (eCBs) and related molecules behaving as ligands of PPAR-alpha, and of oxidative-stress markers such as lipoperoxides, while Western Blot and immunohistochemistry were used to study protein expression of cannabinoid receptors, COX-2 and PPAR-alpha. Unpaired Student's t-test was used to evaluate statistical differences between groups.
  
  
  RESULTS
  The acute BCCAO/R procedure is followed by increased brain tissue levels of the eCBs 2-arachidonoylglycerol and anandamide, palmitoylethanolamide, an avid ligand of PPAR-alpha, lipoperoxides, type 1 (CB1) and type 2 (CB2) cannabinoid receptors, and COX-2, and decreased brain tissue concentrations of docosahexaenoic acid (DHA), one of the major targets of lipid peroxidation. In plasma, increased levels of anandamide and lipoperoxides were observed.
  
  
  CONCLUSIONS
  The BCCAO/R stimulated early molecular changes that can be easily traced in brain tissue and plasma, and that are indicative of the tissue physiological response to the reperfusion-induced oxidative stress and inflammation. The observed variations suggest that the positive modulation of the ECS and the increase of proinflammatory substances are directly correlated events. Increase of plasmatic levels of anandamide and lipoperoxides further suggests that dysregulation of these molecules may be taken as an indicator of an ongoing hypoperfusion/reperfusion challenge.
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy. quartu@unica.it.
authors.forename: Marina
authors.identifier: http://orcid.org/0000-0002-1884-3597
authors.initials: M
authors.lastname: Quartu
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Poddighe
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Melis
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Maria Pina
authors.initials: MP
authors.lastname: Serra
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Boi
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Lisai
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Gianfranca
authors.initials: G
authors.lastname: Carta
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Murru
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Muredda
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Collu
authors.affiliation: Department of Biomedical Sciences, Cittadella Universitaria di Monserrato, 09042, Monserrato, CA, Italy.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Banni
mesh_terms: D000577:Amides; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D017536:Carotid Artery, Common / Q000601:surgery; D002561:Cerebrovascular Disorders / Q000378:metabolism* / Q000503:physiopathology; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000378:metabolism; D063388:Endocannabinoids / Q000378:metabolism*; D004983:Ethanolamines / Q000378:metabolism; D005625:Frontal Lobe / Q000378:metabolism / Q000503:physiopathology; D005786:Gene Expression Regulation; D005989:Glycerides / Q000378:metabolism; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000378:metabolism*; D008297:Male; D009778:Occipital Lobe / Q000378:metabolism / Q000503:physiopathology; D018384:Oxidative Stress; D047493:PPAR alpha / Q000235:genetics / Q000378:metabolism; D010169:Palmitic Acids / Q000378:metabolism; D053284:Polyunsaturated Alkamides / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology; D013702:Temporal Lobe / Q000378:metabolism / Q000503:physiopathology
chemical_list: D000577:Amides; D001095:Arachidonic Acids; D063388:Endocannabinoids; D004983:Ethanolamines; D005989:Glycerides; D008054:Lipid Peroxides; D047493:PPAR alpha; D010169:Palmitic Acids; D053284:Polyunsaturated Alkamides; D004281:Docosahexaenoic Acids; C005958:palmidrol; C094503:glyceryl 2-arachidonate; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; C078814:anandamide
keywords: Bilateral common carotid artery occlusion; COX-2; Cerebral cortex; Endocannabinoid system; Lipoperoxides; Reperfusion