Effect Of Combinatorial Treatment With Swimming Exercise And Low-fat Diet On Learning And Memory Function Of Development Spontaneously Hypertensive Rats

Objective:Low-fat diet is one of the non-drug nursing prescriptions to control hypertension But it may have negative effect on neural development of children,while decrease blood pressure.Swimming exercise can promote neural development,as well as has anti-hypertensive effect.The spontaneously hypertensive rats of development stage were used as the model.Combinatorrial treatment with forced swimming exercise and low-fat diet were used on the rats.The blood pressure and ability of spatial learning and memory of the rats were detected.The factors regulating learning and memory function were investigated by the molecular biology techniques.We aimed to find a combinatorial lifestyle treatment which has neuroprotective effect on cognitive function deficit of pediatric hypertension and simultaneously has synergetic anti-hypertension effects,and explore the possible mechanism.The experiment could provide data support to make non-drug anti-hypertension nursing prescription for hypertensive childrenMethods:1.Animals and groups:Male spontaneously hypertensive rats(SHR)of 3 weeks old were randomly divided into four groups,which was control(Con)group,low-fat diet(LFD)group,forced swimming exercise(FSE)group,and combinatorial treatment with forced swimming exercise and low-fat diet(FSE/LFD)group2.Exercise and diet program:(1)The formal swimming training of SHR was 60 min forced swimming exercise per day,six days per week(from Monday to Saturday)(2)The control diet(CTD)was development rat formula feeds.The content of the soybean oil in the LFD was reduced to 1/2 of that in the CTD.So,the fat-energy ratio of the LFD and CTD was respectively 10.7%and 17.2%.The vitamin and mineral mixture were all the same as that of CTD(3)The swimming and diet treatments were applied for 6 weeks3.Blood pressure of SHR was measured using noninvasive tail-cuff method4.Weight of SHR was detected by electronic body weightometer.5.Morris water maze was used to detect the spatial learning and memory function of development SHR.6.Long-term potentiation(LTP)was used to detect the synaptic plasticity of CA3-CA1 pathway in hippocampus of development SHR.7.Western blot and immunohistochemistry were used to detect the expression of NMDAR1 and BDNF in development SHR hippocampus.Results:1.Effect of swimming exercise and low-fat diet on blood pressuer of development SHR.Combinatorrial treatment with 60mim/d forced swimming exercise and 10.7%fat energy ratio of low-fat diet decreased the blood pressure of development SHR than either intervention alone(P<0.05).2.Weight of FSE/LFD group significantly decreased than those of Con,LFD or FSE group(P<0.05).3.Distinct treatments influenced the spatial learning and memory ability in the Morris water test of development SHR.In the acquisition trail of test,LFD group had dramatic longer swimming distance than those of Con and FSE/LFD group for test of day 2 to 4(P<0.05).LFD group had dramatic longer escape latency than those of Con and FSE/LFD group for test of day 2 and 3(P<0.05).There was no significant difference between FSE/LFD group and Con group on the swimming distance and escape latency for test of day 1 to 5(P>0.05).In the probe trial test of day 6,LFD group of SHR stayed less time and swimming distance in the target quadrant compared with the Con and FSE/LFD group(P<0.05).The time and swimming distance in the target quadrant did not change significantly between FSE/LFD group and Con group(P>0.05).4.Distinct treatments influenced the CA3-CA1 pathway LTP in hippocampus of development SHR.fEPSP amplitude of LFD group was distinctly suppressed compared to that of the Con group after a tetanic stimulation(TS)(P<0.05);While,fEPSP amplitude of FSE/LFD group significantly increased than that of Con group after TS(P<0.05).5.Distinct treatments influenced the expression of NMDAR1 in hippocampus of development SHR.The expression of NMDAR1 in hippocampus of development SHR significantly decreased in the LFD group than that of the Con group(P<0.05).However,the protein level of NMD AR1 in the FSE/LFD group was dramatic higher than that of the LFD and Con group(P<0.05).6.Distinct treatments influenced the expression of BDNF in hippocampus of development SHR.The expression of BDNF in hippocampus of development SHR obviously decreased by the treatment of LFD(P<0.05).While,the protein level of BDNF in development hippocampus significantly up-regulated in the FSE/LFD group compared to that of the LFD and Con group(P<0.05).Conclusion:1.Combination of 60min/d forced swimming exercise and 10.7%fat energy ratio of low-fat diet noteworthy reduces elevated blood pressure than either use of them alone.2.10.7%fat energy ratio of low-fat diet treatment impaires the spatial learning and memory function as well as synaptic plasticity of development SHR.Combinatorrial treatment with 60mim/d forced swimming exercise and 10.7%fat energy ratio of low-fat diet remedies learning and memory as well as synaptic plasticity damage of development SHR caused by 10.7%fat energy ratio of low-fat diet treatment.3.The underlying mechanism of the combinatorrial treatment with 60mim/d forced swimming exercise and 10.7%fat energy ratio of low-fat diet that affects spatial learning and memory function can be:exercise markedly remedies the decreased level of BDNF induced by low-fat diet associated with up-regulating expression of NMDAR1.