Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9429693 | Neuroscience Letters | 2005 | 5 Pages |
Abstract
The aim of the present study was to investigate the first protective window of preconditioning with electroacupuncture (EA) against focal cerebral ischemia, and to explore whether adenosine is involved in the rapid tolerance phenomenon. Sixty-four male Sprague-Dawley rats were randomly assigned to eight groups (n = 8 in each). Animals in the control group received no treatment, and animals in EA1-EA4 groups received EA at 0.5, 1, 2 and 3 h before induction of focal cerebral ischemia, respectively. Rats in DPCPX group were intraperitoneally injected with 1 mg kgâ1 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), 3 h before induction of focal cerebral ischemia. Animals in vehicle group and EA + DPCPX group were pretreated with 1 ml kgâ1 dimethyl sulfoxide (DMSO, the solvent of DPCPX) and 1 mg kgâ1 DPCPX 30 min before preconditioning with EA, respectively. All rats were anesthetized with 40 mg kgâ1 pentobarbital sodium intraperitoneally. Animals that required EA preconditioning, received EA with intensity of 1 mA and frequency of 15 Hz at the Baihui acupoint (GV 20) for 30 min. The focal cerebral ischemia was produced by the right middle cerebral artery occlusion (MCAO) for 120 min. The neurologic deficit scores (NDS) and brain infarct volumes were evaluated at 24 h after reperfusion. All rats survived until 24 h after reperfusion. Preconditioning with EA at 2 h before induction of focal cerebral ischemia improved neurologic outcome (P < 0.05 versus control) and reduced the infarct volume (P < 0.01 versus control) at 24 h after reperfusion. These beneficial effects were reversed by pretreatment with 1 mg kgâ1 DPCPX, whereas this agent itself did not affect the NDS and volume in drug-ischemic controls after ischemia. The results show that preconditioning with single EA session induces rapid tolerance to focal cerebral ischemia. The rapid ischemic tolerance appears at 2 h (but not at 0.5, 1, or 3 h) after preconditioning, and is possibly mediated through an adenosine A1 receptor-related mechanism.
Related Topics
Life Sciences
Neuroscience
Neuroscience (General)
Authors
Qiang Wang, Lize Xiong, Shaoyang Chen, Yanhong Liu, Xiaoling Zhu,