Effects of treadmill running pretreatment on the expression of CyclinA and CyclinE protein in hippocampus of rats after global cerebral ischemia and reperfusion

Abstract

Objective To investigate the effect of treadmill running pretreatment on the expression of CyclinA and CyclinE protein in hippocampus of rats after global cerebral ischemia and reperfusion. Methods 60 healthy male wister rats were randomly divided into control group, model group and experiment group. Global cerebral ischemia reperfusion model was generated by improved four-vessel occlusion as described according to the description of Pulsinelli's method. Rats in the experiment group were performed treadmill running for 2 weeks before injury. The water maze test was performed at 24 h and 48 h respectively after injury to determine the spatial memory ability of rats. Morphological changes of hippocampus were observed by HE staining (hematoxylin-eosin staining) at 3 h, 6 h, 24 h, 48 h after injury and the expression of CyclinA and CyclinE were detected by immunohistochemical staining. Results Compared with control group, the survival rate of neurons in the model group was significantly decreased at each time point. Morris water maze test showed that the escaping latency of rats in the model group was significantly prolonged(24 h(24.35±3.99)s, 48 h(33.08±5.85)s), and the frequency of crossing the platform was decreased(24 h(6.80±0.79), 48 h(4.00±0.67)). The expression of CyclinA was increased significantly in the model group((8.40±0.52)/high view, (11.70±1.06)/ high view, (15.50±0.53)/ high view, (22.40±0.52)/ high view) as well as the expression of CyclinE((20.30±0.48)/ high view, (15.20±0.63)/ high view, (10.00±0.82)/ high view, (7.70±0.68)/ high view) (P<0.05). Compared with model group, the survival rate of neurons in the model group was significantly increased at each time point. Morris water maze test showed that the escaping latency of rats in the experiment group was significantly shorten(24 h(13.21±2.73)s, 48 h(24.20±4.66)s), and the frequency of crossing the platform was increased(24 h(9.70±0.95), 48 h(6.30±1.16)). The expression of CyclinA was significantly increased in the model group((10.60±0.84)/ high view), (16.70±0.68)/ high view), (24.50±0.53)/ high view), (36.20±1.40)/ high view) as well as the expression of CyclinE((31.60±0.70)/ high view), (24.50±0.70)/ high view), (16.80±0.63)/ high view), (9.10±0.74)/ high view) (P<0.05). Conclusion The treadmill running pretreatment improves the function of spatial memory after global cerebral ischemia and reperfusion, potenlially mediated by regulating the expression for cell cycle proteins, which have a protective effect on cerebral brain tissue. Key words: Global cerebral ischemia; Treadmill running; CyclinA; CyclinE