Effect of acupuncture on cholinergic anti-inflammatory pathway in hippocampus of aged rats during global cerebral ischemia-reperfusion

Abstract

Objective To investigate the effect of acupuncture on cholinergic anti-inflammatory pathway in the hippocampus of aged rats during global cerebral ischemia-reperfusion (I/R). Methods Ninety-six clean-grade healthy male Sprague-Dawley rats, aged 17-22 months, weighing 440-580 g, were divided into 3 groups (n=32 each) using a random number table method: sham operation group (group S), global cerebral I/R group (group I/R) and acupuncture group (group AP). Global cerebral I/R was induced by 4-vessel occlusion method described by Pulsinelli in group I/R and group AP.Baihui and Fengchi were stimulated for 14 consecutive days before ischemia in group AP.Four rats were sacrificed at 1, 3, 5 and 7 days of reperfusion, and brains were removed for determination of neuronal apoptosis by TUNEL.Four rats were sacrificed at 1, 3, 5 and 7 days of reperfusion, and brains were removed for determination of the expression of α7 nicotinic acetylcholine receptor (α7nAChR), choline acetyltransferase (ChAT), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the hippocampal CA1 region by Western blot.The apoptosis rate was calculated. Results Compared with group S, the apoptosis rate of hippocampal neurons was significantly increased, and the expression of α7nAChR, ChAT, TNF-α and IL-1β was up-regulated at each time point of reperfusion in I/R and AP groups (P<0.05). Compared with group I/R, the apoptosis rate of hippocampal neurons was significantly decreased, the expression of α7nAChR and ChAT was up-regulated, and the expression of TNF-α and IL-1β was down-regulated at each time point of reperfusion in group AP (P<0.05). Conclusion The mechanism by which acupuncture mitigates global cerebral I/R injury may be related to activating cholinergic anti-inflammatory pathway in the hippocampus of aged rats. Key words: Acupuncture; Reperfusion injury; Brain; Aged; Cholinergic anti-inflammatory pathway