Swimming Training With Different Intensities On Cerebral Ischemia And Reperfusion Rats Protein Kinase A Expression

Objective To observe the effects of intensive-swimming training at different intensities on the neurological function and the expressions of proteinkinase A after cerebral ischemla-reperfusion in rats, and to explore the possible neuroprotectional mechanism of intensive-swimming training after cerebral ischemla-reperfusion in rats.Methods To establish animal model of cerebral ischemia-reperfusion in rats, the intraluminal thread method was applied to cause left middle cerebral artery occlusion (MCAO) for2h and before reperfusion.120male model SD rats were randomly divided into training group1(swimming for5min once a day), training group2(swimming for10min once a day), training group3(swimming for20min once a day) and control group (no training), and30rats each group. Another30rats assined to the sham-operation group were subject to no MCAO and no training, Above the five groups were randomly divided into three groups of3rd,7th and14th d, and10rats each group. Neurological function was evaluated by Menzies scores and forelimb placing. Expressions of proteinkinase A were detected by immunohistochemistry. Expressions of PKA-mRNA were detected by RT-PCR.Results The neurological function in sham-operation group was normal. The differences of Menzies scores and forelimb placing at same time points between sham-operation group and control group were statistically significant(P<0.05). The improvement of neurological function in all training groups, were significantly better than those in controls at the3rd,7th and14th d after swimming training(P<0.05), especially in the training group3. After they had trained for3d,7d, and14d in the training group3, the Menzies scores were respectively (1.40±0.55),(1.00±0.71) and (0.80±0.45),and the forelimb placing scores were respectively (5.20±0.84),(3.80±1.30) and (2.40±1.14). The rates of positive cells and the expressions of mRNA about proteinkinase A in all training groups were higher than those in controls at the3rd,7th and14th d after swimming training (P<0.05), and the increase of positive cells and mRNA of PKA in training group3was significantly more obvious compared with other training groups(P<0.05). After they had trained for3d,7d, and14d in the training group3, the expressions’ ratios of proteinkinase A were respectively (32.84±1.66)%,(35.05±1.33)%and (45.92±2.03)%, and the expressions of PKA mRNA were respectively (32.18±0.86)%,(37.44±1.27)%and (42.77±0.81)%. Conclusions Exercise training can increase the expression of positive cells and mRNA of PKA in rats after cerebral ischemla-reperfusion, hence, it improved the injured neurological function and promote the recover of sensory function and motor function, and the more intensive the training, the better the effects.