| Objective: To investigate the effect of the eight-week’s swimming exercise of moderate-load and excessive- load on spatial memory and the expression of OX1R and ORX-A in rat’s frontal lobe The experimental. methods: selecting 40Sprague-Dawley(SD) male rats which were 2-month- old and without specific pathogen were adaptive feed for 3 days, then adjusting the Morris water maze and the behavior test was carried out to eliminate rats which were significant difference with others. Then the rats were randomly divided into three groups: control group(MDWC,10) moderate-load group(MDWM, 13), excessive-load group(MDWO,17)and navigation experiments were carried out for 7 days and one day for space exploration experiment.After that,the control group were feed freely for 8 weeks; the moderate-load group swam a time every day.It was 10 min on the first day, then increasing 5 min every day until reached 60 min at the second weekend. After that,maintained 60 min one dag for 7 weeks;The load of excessive-load group was same with that the moderate load group at 1th and 2th weeks, since 3th week, increasing10 min every day until 120 min, the load was formed with 1%W(weight) and 120 min/days since the 4th weeks, then the weight increased 1%W weekly and the time of swimming was 120 min until the end of the 8th weeks. The moderate-load group and the excessive-load group were daily 19:00 swimming, training six days a week, a total of 8 weeks. After the swimming-exercise intervention, one day for space exploration experiment to determine the effect of different exercise load on the extraction of spatial memory in rats.Thereafter decapitated and the Real time PCR was used to detect the expression of ORX-A and OX1RmRNA in the frontal lobe; immuno-fluorescence and Western blot were used to detect the expression level of the protein.Results:(1) in the navigation experiments, after 4 days,the three groups of rats were into incubation period of the platform, and there was no difference about the average escape latency time among them(P > 0.05);( 2) in the space exploration experiments, before the exercise intervention, three groups of rats went into the water from four quadrant respectively and there was no differences among groups(P>0.05); after the exercise intervention,the times that the group of MDWM crossed the platform were more than the group of MDWC(P < 0.05); while the times that the group of MDWO crossed the platform were less than the group of MDWC(P < 0.05); besides there was nodifferences among groups before and after intervention(P < 0.05, P < 0.01).(3)after the third week, the weight of the group of MDWM and MDWO was less than the group of DWMC(P < 0.01); after the fifth week, the weight of the group of MDWO was less than the group of MDWM(P < 0.01);(4) the immuno-fluorescence, Western blot and PCR were used to detect the effect of different load exercise on OX1R and ORX-A,.Results showed that the expression of ORX-A mRNA in the group of MDWM was higher than the group of MDWC(P < 0.05),while which in the group of MDWO was much lower than the group of MDWC(P < 0.01); the expression of OX1RmRNA in the group of MDWM was lower than the group of MDWC(P <0.05). the expression of OX1RmRNA in the group of MDWO was higher than the group of MDWC(P<0.05);the protein expression of OX1R in the group of MDWM was lower than the group of MDWC(P<0.05);the protein expression of OX1R in the group of MDWO was higher than the group of MDWM(P<0.05).Conclusions:(1) the moderate load intervention up-regulation the the expression of ORX-A mRNA,which increases the spatial memory of rats;(2) after the eight-week’s swimming exercise of excessive-load,the blood testosterone levels and the weight of group O is lower than the group C and M,which means the mold of excessive- load is successful;(3) the excessive-load intervention down-regulation the the expression of OX1R mRNA,which damages the spatial memory of rats;... |
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