Effects of Aerobic Exercise on Behavior and Oxygen Free Radicals in Rats with Mental Stress
[Abstract] Objective: To study the effects of aerobic exercise on the behavior and peripheral blood oxygen free radicals in rats with psychological stress.
Methods: Twenty-eight healthy female Sprague-Dawley rats were randomly divided into control group, exercise group, psychological stress group and exercise + psychological stress group. The experimental behavior and the changes of peripheral blood free radicals were determined after the experiment.
Results: 1 Opening behavior: Compared with the control group, the exercise group, the psychological stress group, the exercise + psychological stress group and the control group showed significant increase (P < 0.05), and the psychological stress in the number of standing times. The group, exercise + psychological stress group was significantly reduced compared with the control group and the exercise group (P < 0.01). 2 Serum S OD activity, H2O2 content: There was no significant difference between the groups; MDA content: exercise group, exercise + psychological stress group compared with the control group and psychological stress group showed significant reduction (P < 0. 05); Catalase (CAT) activity: CAT activity in exercise group was significantly higher than that in psychological stress group (P < 0.05); GSH - px activity: compared with control group, exercise group, exercise + psychological should The activity of the stimulation group was significantly increased (P < 0.05), and the psychological stress group was significantly lower (P < 0.05).
Conclusion: Unsuitable psychological stress can affect the spontaneous release and inquiry behavior of animals, and can induce the increase of free radicals in the body and cause damage to the body. The aerobic exercise can reduce the impact of psychological stress on the body. .
[Key words] aerobic exercise; psychological stress; aging rats; opening behavior; free radicals
Free radical theory is a discipline that has been widely recognized by the life sciences since the 1980s. The effect of free radicals on the body is mainly determined by its high activity and reactivity. Free radicals easily react with various biological macromolecules, causing oxidative damage of cells and tissues, causing various physiological functions of the body to decline and hinder. , leading to the aging and death of the organism. Many studies have shown that damage can be caused to various tissues of the body by inducing free radical reactions [1, 2]. The psychological stress on the body is manifested as: inappropriate psychological stress can cause changes in the animal's opening behavior and can induce the body to produce a large number of free radicals, and damage to the brain, liver, heart, kidney and other tissues [ 3 ]. In this study, autistic SD rats were trained in moderate-intensity aerobic exercise, while applying a certain degree of psychological stimulation, and observed the opening behavior of rats and superoxide dis2mutase (SOD) in peripheral blood. , glutathione peroxidase (GSH2 px), catalase (CAT), malondialdehyde (MDA), hydrogen peroxide (H2O2) content changes, further The research provides a theoretical basis for reducing the effect of psychological stress on the amount of free radicals produced by exercise training, thereby reducing the damage of free radicals to the body and achieving the purpose of delaying aging.
1 Materials and methods
1.1 Animal selection and grouping
49 female SD rats of 3 months old and 7 female SD rats of 20 months old (all purchased from the Animal Center of Jiangsu University Medical College). Rats aged 3 months were randomly divided into aging control group (14), psychological stress group (7), exercise group (7), exercise + psychological stress group (7), and blank control group (7). And electric shock group (7). The rats in the first 4 groups were prepared into aging model rats, and the blank control group and the electric shock group were not treated. After the aging model was prepared, 7 rats from the aging control group were randomly selected to evaluate the aging model with the blank control group and the old age group.
1.2 Modeling method
1 . 2 . 1 aging model using D2 galactose subcutaneous injection method: D2 galactose with physiological saline solution to a concentration of 7.5% of the injection, 3 months old model rats abdominal subcutaneous injection of D2 galactose 125 mg · Kg-1·d- 1, continuous injection for 42 d [4].
1 . 2 . 2 Psychological stress model using the rat bystander electric shock model (Communicati on Box), the rats in the electric shock group were shocked and shocked, and the rats in the stress group were not subjected to electric shock, but the rats in the electric shock group. The process of electric shock produces psychological stress through visual, auditory, etc. [5].
1.3. Modeling interventions in each group
Control group: Usually do not exercise, nor stress. Psychological stress group: The first 8 weeks were the same as the control group, and the stress lasted for 30 minutes from the 9th week, once every other day, to the 10th week. Exercise group: Adapt to training for 30 minutes every day for the first 3 days, then swim once a day without weight-bearing, 60 minutes each time for 10 weeks. The exercise group + psychological stress group: the first 8 weeks are the same as the exercise group. From the 9th week, psychological stress is added at the same time, and the psychological stimulation and exercise are performed in the morning and afternoon, respectively, to the 10th week.
1. 4 Movement and stress
1 . 4 . 1 The exercise mode aging model has no weight-bearing swimming after preparation. The water temperature is 31-33 ° C and the water depth is 60 cm. The rats are controlled to swim continuously. One time each time, 1 hour each time, 5 times a week for 10 weeks, the control rats were placed in shallow water of the same conditions to avoid the difference in stimulation of water temperature on the rats.
1 . 4 . 2 Psychological stress mode The aging model begins to stress from the 9th week after the preparation. Each stress is carried out in batches. Each stress lasts for 30 minutes, once every other day for 2 weeks. After each stress was completed, the model control group was placed in the cleaned bystander box for 30 min to maintain the same experimental conditions.
1.5 Opening behavior After the last psychological stress or 24 h after the last swimming, the animal was placed in a black wall of 75 cm × 65 cm × 47.5 cm, and the bottom surface was divided into 25 bottomed fields with equal area. The laboratory is soundproofed with an illumination of 60W. The number of cells running through the bottom surface and the hind limb standing (including the forelimb buttress and hanging) were observed within 3 minutes from the center of the bottom surface.
1.6 Determination of biochemical indicators
Superoxide dismutase (SOD), glutathione peroxidase (GSH2 px), catalase (CAT), malondialdehyde (MDA), hydrogen peroxide (H2O2) assay kits were purchased from Nanjing Established the Institute of Bioengineering. After the last psychological stress or 24 h after the last swimming, the opening behavior was measured and fasted for 12 h, followed by anesthesia, and blood was prepared after cardiac blood sampling. The specimen to be tested was prepared according to the requirements of each kit. Measuring instrument: 722 spectrophotometer.
1. 7 result processing
The data was analyzed and processed by SPSS software using one-way ANOVA.
2 results
2.1 results of the aging model
The comparison of serum biochemical indicators in each group is shown in Table 1.
Table 1 shows that in addition to serum SOD, serum GSH2 px and CAT were significantly higher in the blank control group than in the aging control group (P < 0.05), while MDA content was significantly lower than that in the aging control group (P < 0 . 05); There was no significant difference in serum SOD, GSH2, px, CAT and MDA between the two groups in the aging control group and the aging group.
2.2 The effect of aerobic exercise on the opening behavior of aging rats with psychological stress
The opening behavior of each group of animals is shown in Table 2.
Crossing the number of grids
Aging control group 40 . 00 ± 2 . 236 20 . 40 ± 1 . 749
Sports group 48 . 20 ± 1 . 772 21 . 40 ± 1 . 435
Psychological stress group 51. 60 ± 3 . 982 13 . 60 ± 1 . 030
Exercise + psychological stress group 49. 80 ± 1 . 655 14 . 20 ± 1 . 241
Table 2 shows that the exercise group, the psychological stress group, the exercise + psychological stress group and the aging control group showed a significant increase in the number of crossing aging rats (P < 0.05), of which the psychological stress group The increase was most significant (P < 0.01); in the number of standing, the psychological stress group, the exercise + psychological stress group were significantly reduced compared with the aging control group and the exercise group (P < 0.01), while the exercise group was There was no significant difference from the aging control group.
2.3. Effect of aerobic exercise on oxygen free radicals in serum of aging rats with psychological stress
GSH2 px activity in serum: Compared with the aging control group, the activity in the exercise group, exercise + psychological stress group was significantly increased (P < 0.05), and the psychological stress group was significantly lower than the aging control group (P <0. 05). CAT activity in serum: CAT activity in exercise group was significantly higher than that in psychological stress group (P < 0.05), and there was no significant difference among the other groups. MDA content in serum: exercise group, exercise + psychological stress group and aging control group and psychological stress were significantly reduced (P < 0.05), there was no significant difference between aging control group and psychological stress group . The serum H2O2 content was lower in the exercise group, exercise + psychological stress group than in the aging control group and the psychological stress group, but there was no significant difference between the groups.
3 Discussion
3.1 results of the aging model
The serum GSH2 px and CAT activities in the blank control group were significantly higher than those in the aging control group, while the serum MDA content was significantly lower than that in the aging control group. There was no significant difference in serum SOD, GSH2 PX, CAT and MDA between the aging control group and the aging group. We can think that the aging model is successful, and the aging rats after 42 days of subcutaneous injection of D2 galactose 125 mg·kg-1·d-1 are equivalent to the aged rats with natural growth of about 21 months.
3.2 The effect of aerobic exercise on the opening behavior of aging rats with psychological stress
The determination of the opening behavior has now become an important indicator for studying the fear and nervousness of animals. The crossing number and standing times of the rats represent the spontaneous release and inquiry behavior of the rats in the new environment. However, because psychological stress is a very complicated process, the impact of psychological stress on the opening behavior is still divergent in the research results. Yan Jin et al [6] research shows that animals are nervous due to psychological stress, and there will be a decrease in the number of crossings and a decrease in the number of standings; while the research by Zheng Leying et al [7] supports animals due to psychological stress. The phenomenon of increasing the number of crossings and increasing the number of standings. The results of this experiment show that due to psychological stress and aerobic exercise intervention, the number of crossings in aging SD rats increased significantly, and the increase in psychological stress group was the most significant, indicating that psychological stress can cause aging SD rats to cross the grid. The number increases, while aerobic exercise has the effect of reducing the impact of psychological stress on the body. In the number of standing times, the psychological stress group and the exercise + psychological stress group were significantly lower than the control group and the exercise group. It can be considered that psychological stress can cause the number of standing aging SD rats to decrease.
3. 3 Effect of aerobic exercise on oxygen free radicals in serum of aging rats with psychological stress GSH2 px, CAT, SOD are antioxidant enzymes widely present in living organisms, representing the activity of antioxidant systems in the body, they can clear O -
2, H2O2 and other oxygen free radicals, and the body's excess superoxide ions maintained at a certain level, the level of its activity directly or indirectly reflects the body's ability to scavenge oxygen free radicals. The results of this experiment showed that the GSH2 px activities in each group showed significant differences, and the activity level can be ranked according to the psychological stress group < aging control group < exercise + psychological stress group < sports group order, and The CAT activity in the psychological stress group was also significantly lower than that in the exercise group. It is indicated that inappropriate psychological stress causes a decrease in the activity of the enzyme defense system in the animal body, while aerobic exercise training can increase its activity. This is consistent with the results of most scholars such as Hou Gonglin, Sha Jibin, etc., so we can also think that the training of aerobic exercise can reduce the damage caused by psychological stress. MDA is an important metabolite of lipid peroxidation in the body and has serious toxic effects on cells. The content of MDA in serum can reflect the degree of lipid peroxidation in the body, which indirectly reflects the degree of cell damage. In this experiment, the serum MDA content in the control group and the psychological stress group was significantly higher than that in the exercise group and the exercise + psychological stress group, indicating that aerobic exercise can significantly improve the production of lipid peroxide caused by psychological stress. Alleviate the damage of free radicals to various tissues and organs of the body. In summary, we can think that inappropriate psychological stress can reduce the activity of the body's antioxidant system, and can induce the increase of free radicals in the body, and the appropriate aerobic exercise training can alleviate this stress on the body. The effect of aerobic exercise can alleviate the damage of psychological stress to the body to a certain extent.
