title: A short cerebral ischemic preconditioning up-regulates adenosine receptors in the hippocampal CA1 region of rats.
abstract: Pharmacologically blocking or stimulating studies have showed the crucial role of adenosine receptors in the protective effect of cerebral ischemic preconditioning (CIP). However, little is know about whether the adenosine receptors are up-regulated in the process. In the present study, changes in expression of adenosine receptors in the CA1 hippocampus after a short CIP in a period of 3 min were investigated in rat four-vessel occluding (4VO) brain ischemic model using immunohistochemistry. The experiments were performed on groups of sham, 4 h, 1, 3, and 7 days (n = 6 in each group) after the CIP. The number and immunostaining density of immunoreactive cells for A1 and A2b adenosine receptors in the CA1 hippocampus were significantly increased after the CIP. For A1 adenosine receptor, the increase occurred in CA1 pyramidal neurons. While for A2b adenosine receptor, the increase occurred in the stratum radiatum of the CA1. The immunoreactive cells for A2b receptor showed distinct morphological characteristics of astrocytes. The increases were consistent in time course (1-7 days) with the development of the ischemic tolerance induced by the CIP. It was concluded that up-regulation of adenosine receptors may also play an important role in the protective effect of CIP.
authors.affiliation: Department of Pathophysiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, PR China.
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Zhou
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Li
authors.forename: Qing-Jun
authors.initials: QJ
authors.lastname: Li
authors.forename: Hui-Qing
authors.initials: HQ
authors.lastname: Liu
authors.forename: Rong-Fang
authors.initials: RF
authors.lastname: Feng
authors.forename: Hong-Gang
authors.initials: HG
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002545:Brain Ischemia / Q000378:metabolism*; D006624:Hippocampus / Q000098:blood supply* / Q000378:metabolism; D007150:Immunohistochemistry; D019194:Ischemic Preconditioning; D051381:Rats; D017207:Rats, Sprague-Dawley; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D018047:Receptors, Purinergic P1