title: Cannabinoid receptor type 2 activation yields delayed tolerance to focal cerebral ischemia.
abstract: We demonstrated in our previous research that pretreatment with electroacupuncture (EA) induces rapid (2h after EA) and delayed (24h after EA) tolerance to focal cerebral ischemia. We further elucidate the endocannabinoid and cannabinoid receptor type 1(CB1) involvment in the rapid ischemic tolerance induced by EA pretreatment. The present study aimed at investigating the involvement of the cannabinoid receptor type 2 (CB2) in the neuroprotection conferred by EA pretreatment. Focal cerebral ischemia was induced by middle cerebral artery occlusion for 120 min at 2h and 24h following EA pretreatment in male Sprague-Dawley rats, respectively. Cerebral ischemic injury was evaluated by neurobehavioral scores and infarction volume percentages 72 h after reperfusion in the presence or absence of AM251, a selective CB1 receptor antagonist, and AM630, a selective CB2 receptor antagonist. The expression of CB1 and CB2 receptor in the striatum of ischemic hemisphere was also evaluated. The rapid and delayed ischemic tolerance induced by EA pretreatment was respectively reversed by AM251 and AM630. CB2 receptor expression was up-regulated in the striatum of rat brains at 24h after EA stimuli. These results indicate that CB2 receptor contributed to the delayed neuroprotective effect whereas CB1 receptor to the rapid ischemic tolerance induced by EA pretreatment against focal cerebral ischemia in rats.
authors: Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China.
authors: Lei
authors: L
authors: Ma
authors: Zhenghua
authors: Z
authors: Zhu
authors: Yu
authors: Y
authors: Zhao
authors: Lihong
authors: L
authors: Hou
authors: Qiang
authors: Q
authors: Wang
authors: Lize
authors: L
authors: Xiong
authors: Xiaoling
authors: X
authors: Zhu
authors: Ji
authors: J
authors: Jia
authors: Shaoyang
authors: S
authors: Chen
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy*; D019610:Cytoprotection / Q000502:physiology*; D004195:Disease Models, Animal; D015671:Electroacupuncture / Q000379:methods*; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D043885:Receptor, Cannabinoid, CB2 / Q000037:antagonists & inhibitors / Q000502:physiology*
chemical_list: D043885:Receptor, Cannabinoid, CB2