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: 28 female S D rats were randomly divided into control group, exercise group, group psychological stress, exercise + psychological stress group, open field and experimental rats was measured after the radical changes in the peripheral blood.

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 (free radical theory) since the beginning of the 1980s is widely valued by the life sciences community a discipline. 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. At present, many studies have shown that can cause damage [1, 2] of the body of the tissue induced by a radical reaction. 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

3-month-old female SD rats were 49, 20-month-old female SD rats 7 (were purchased from Animal Center of Jiangsu University School of Medicine). Aged rats were randomly divided into three group (14), psychological stress group (7), exercise (7), exercise + psychological stress group (7), the blank control group (7) and 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 to a concentration of 7.5% of the injection , 3 months old model rats subcutaneous injection of D2 galactose 125 mg · Kg- 1 · d- 1 , continuous injection for 42 d [ 4 ] .

. 1. 2. 2 Stress Model using bystander shock model (Communicati on Box) rats are group are screaming shock shock, startle, shock from the control rats, rats shock but sidelines process of electric shock, psychological stress [5] through visual, audible, and the like.

1.3 Modeling interventions in each group

Control group : usually do not exercise , nor stress. Psychological stress group: 8 weeks before the same group, from the 9th week duration each stress 30min, 1 day to 10 weeks. Exercise group: 3 days before the training to adapt to a day 30 min, then swim every day without load once every 60min, a total of 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 exercise and stress

1.4.1. Movement mode After the preparation of the aging model, no weight-bearing swimming , water temperature 31 ~ 33 °C , water depth of 60 cm, artificially controlled rats continue to swim. 1 times a day, 1 h, 5 times a week, for 10 weeks, the control group rats were placed in shallow water the same conditions, the temperature difference in order to avoid irritation in rats produced.

From the 9th week after preparation aging mold 1. 4.2 Mental Stress start stress, stress each batchwise, continuous stress every 30min, 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 areas . 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

Data analyzed by the 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: In addition Serum SOD, serum GSH2 px blank control group, CAT indicators were significantly higher than the aging in the control group (P <0 05.), The content of MDA is significantly lower than the aging in the control group (P <0. 05); aging aging compared with the control group, group, the levels of serum SOD, GSH2 px, CAT, MDA content of no significant difference.

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: exercise group, group psychological stress, exercise + psychological stress and aging group compared to control group, the number of cell senescence through SD rats increased significantly (P <0 05.), Where 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.

Effects 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 was significantly higher than the motion psychological stress group (P <0 05.), No significant differences 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 . Serum H2O2 content: exercise group, group motion + psychological stress is lower than the aging in the control group and the group of psychological stress, but each group had no significant difference.

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 . 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. Effect of aerobic exercise on the opening behavior of aging rats with psychological stress

The opening measuring behavior has now become an important indicator of animal fear, nervousness, ambulation and standing rats represent the number of spontaneous behavior and exploratory behavior in rats in a novel 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] studies have shown that: animals due to psychological stress and tension generated, there will be reduction in ambulation, reduce the number of standing and other phenomena of fear; but Zhengle Ying et al [7] supports animal research because of psychological stress arising The phenomenon of increasing the number of crossings and increasing the number of standings. The results of this experiment show that the intervention of psychological stress and aerobic exercise, the number of cells through aging SD rats increased significantly, among which psychological stress group increased most significantly, indicating that psychological stress can cause aging S D rats through 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 The 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 experimental results show that, GSH2 px activity between groups exhibited significant differences, level of activity can be psychological stress group <aging group <motion + psychological stress group <group arranged in the order of movement, 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 Hougong Lin, sand Jibin [3, 8] Most scholars result it is consistent, so that we can also think we can reduce the damage caused by psychological stress on the body through aerobic exercise training. MDA is an important metabolite in the body lipid peroxidation, have serious toxic effects on the cells, MDA in serum may reflect the lipid peroxidation machine, indirectly reflects the degree of cell damage. In this experiment the control group and the group of psychological stress in the content of MDA is significantly higher than the exercise group and the exercise group + psychological stress, show a large number of lipid oxidation through the aerobic exercise can be significantly improved due to psychological stress caused thereby 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.