Effect of hyperbaric oxygen on behavioral and stress related indexes in rats
Study on the relationship between hyperbaric oxygen and behavioral and stress-related indexes in rats ã€Abstract】 Objective To investigate the relationship between hyperbaric oxygen and stress by observing behavioral and stress-related indicators in rats. Methods Twenty Wistar rats were randomly divided into hyperbaric oxygen group and blank control group according to the digital table method. Hyperbaric oxygen group was treated with 0.20 MPa hyperbaric oxygen treatment for 3 weeks. The control group was fed only, at the first and seventh, respectively. On 14 and 21 days, an elevated plus maze test was performed to observe the staying time of the open arms of the rats. The serum levels of corticotropin-releasing hormone, adrenocorticotropic hormone, glucocorticoids and nitric oxide were determined by enzyme-linked immunosorbent assay. Synthase, nitric oxide and tumor necrosis factor. a (TNF.d) content. Results Hyperbaric oxygenation significantly increased the levels of glucocorticoids (GCS) in the peripheral blood of rats, the difference was statistically significant (P<0.05), but the duration of the open arms in the rat elevated plus maze, Nitric oxide system and TNF. The expression of 0 [no significant effect (P>0.05). Conclusion Hyperbaric oxygen treatment accords with the general characteristics of chronic stress, but it does not cause obvious adverse effects on the body, suggesting that one of the mechanisms of hyperbaric oxygen is to act as a kind of benign stress to increase the body's tolerance to stress. [Key words] hyperbaric oxygen; elevated plus maze; HPA axis; nitric oxide system; tumor necrosis factor-Ot; rat Hyperbaric oxygen therapy is widely used in clinical practice, involving many clinical disciplines, recovery after brain trauma, sudden deafness, spinal cord injury and diabetic foot. The changes in pressure and respiratory oxygen concentration during the treatment process are for the body. It is a stressful event, so long-term continuous hyperbaric oxygen treatment may become a chronic stressor, so understanding the effects of hyperbaric oxygen on the body is very important for clinical treatment. For this reason, the author designed this experiment, through the behavior of the rat, the hypothalamus. Pituitary-adrenal cortex (HPA) axis, serum nitric oxide system and pro-inflammatory factors were observed to explore the effects of hyperbaric oxygen on body stress. Materials and Methods 1. Experimental animals and treatment: 20 male Wistar rats, 8 weeks old, weighing 200-250 g, were purchased from the Experimental Animal Center of the Academy of Military Medical Sciences. Familiar with the environment for 7 days, randomly divided into 2 groups according to the digital table method: pure hyperbaric oxygen group and blank control group. Pure hyperbaric oxygen group: 9:00-10:00, 0.20 MPa, 100% oxygen concentration, 10 min of boosting time, 60 min of steady state, 15 min of decompression time, continuous treatment for 21 d; blank control group : Feeding for 21 days. Experimental animals were given free access to drinking water and were exposed to light 12 hours a day. 2. Elevated Cross Maze Test: Elevated Cross Maze (provided by Shanghai Xinsoft Information Technology Co., Ltd.): 35 cm high, 2 open arms (OA) and 2 closed arms 10 cm long and 50 em long, closed arm wall height 25 cm, black on the inside and bottom, 500 W lamp and camera for lighting about 1 m above the elevated cross maze. Experimental procedure: Animals were transferred to the elevated cross test room before each test, familiar with the environment for 10 min, and the experimental animals were placed in the center of the elevated cross maze, facing the open arms, and the rats were recorded for 5 min. The smell of the experimental animals was removed with water before the next test. The hyperbaric oxygen group and the blank control group were subjected to an elevated plus maze test on the first day, the seventh day, the 14th day, and the 21st day after being familiar with the environment for one week. The experimental results are based on the open arm stay time and the number of open arms crossings. 3. Anesthesia and materials: After the completion of the elevated plus maze test, the experimental animals were fed for 1 day, and anesthetized with 20% urethane 0.7 ml/100 g during 9:00-12:00, the muscles were completely relaxed and the cornea was The presence of reflection is a sign of success in anesthesia. Open the abdomen, expose the abdominal aorta, take blood from a 10 ml syringe, shake the tube, centrifuge at 1 000 r/min for 10 min, centrifuge at a radius of r = 15 cm, take the supernatant, and store at 20 °C. 4. Determination of serum specimens: Determination of serum corticotropin releasing hormone (CRH) and adrenocortic hormore (ATCH) by enzyme-linked immunosorbent assay (ELISA) ), glucocorticoids (GCS), nitric oxide synthase (NOS), nitric oxide (NO), and tumor necrosis factor (TNF-d), The kit was purchased from the Biyuntian Biotechnology Institute and tested using the MULTISKAN EX plate reader. 5. Statistical processing: Data were statistically analyzed using SPSS 13.0 software. Raw data were expressed as mean ± standard deviation (element ± s), and repeated measurements were used to observe whether there were differences between groups and within groups. The exclusion test level is set to only =0.05, and the humanity test level is set to d=0.1. P < 0.05 indicated that the difference was statistically significant. Discuss The pathogenic process of chronic stress is complex. Some studies suggest that the pathogenesis of GMS is mainly mediated by GCS resistance to the old J, HPA axis negative feedback barrier, and the increase of pro-inflammatory factors and peripheral GCS in the peripheral circulation as its terminal effect. It is likely to be the ultimate pathogenic pathway of chronic stress, in which the increase of inflammatory factors can promote the decrease of NOS and NO expression, and may induce the occurrence of atherosclerosis. The most prominent manifestation of increased circulating inflammatory factors is morbid behavior, such as decreased desire to explore, decreased feeding and exercise, drowsiness, and decreased cognitive function. Therefore, this experiment firstly observed the degree of stress in rats caused by hyperbaric oxygen by observing the changes of anxiety behavior in rats. The elevated cross maze was first described by File equal to 1985. The observation of the animal's open arms and closed arm stay time was used to evaluate the animal's desire to explore the outside world, so that the degree of anxiety was evaluated. Some scholars found that the evaluation of anxiety was relatively The market test should be direct and accurate. In this experiment, it can be seen that there was no significant difference in anxiety between the hyperbaric oxygen group and the blank control group, suggesting that hyperbaric oxygen treatment may not increase the anxiety level of the experimental animals within 3 weeks. In addition, this experiment also found that after the second week, the open arm stay time of the hyperbaric oxygen group began to decrease, which may be caused by the length of stress time, such as the same chronic restraint stress, different constraints The time leads to the difference in the test results of the open field. The same is true for hyperbaric oxygen. The hyperbaric oxygen treatment time varies, and its behavioral performance may also be different. It is suggested that hyperbaric oxygen therapy may have a cumulative effect on stress damage. Based on the results of this experiment, the authors speculate that the course of hyperbaric oxygen therapy should be maintained within 2-3 weeks, but the above inference still needs to be clarified by further extending the experimental time and increasing the sample size. HPA axis negative feedback disorder is the core of stress pathogenesis, mainly manifested by the continuous excitement of HPA axis during stress, that is, the increase of circulating CRH, ATCH and GCS. This phenomenon can be observed in chronic stress populations such as depression patients and animal models of chronic stress. In this experiment, it was observed that there was no difference in CRH and ATCH upstream of HPA axis in rats treated with continuous hyperbaric oxygen, but the GCS level was significantly increased, suggesting that although hyperbaric oxygen treatment showed an increase in glucocorticoids, it was generally chronic. Different. The asymmetry of the upstream hormone changes and GCS changes in the HPA axis indicates that the hypothalamic-pituitary HPA axis negative feedback pathway is normal. This phenomenon in this experiment is considered to be related to stress intensity. In the clinical study of f, it was found that the expression of ACTH and CRH mRNA decreased in the chronic stress state, but the level of serum GCS continued to increase, such as Cotella et al. In addition to chronic restraint stress, such mild stressors can also cause persistent high levels of GCS in peripheral blood of experimental rats but do not show an increase in CRH and ACTH. Combined with the results of this experiment, it is speculated that the abnormality of the negative feedback function of the HPA axis may exist only in stress events with high intensity and long duration. Hyperbaric oxygen may be a minor stress and does not cause damage to the feedback function of the HPA shaft. In addition, although the HPA axis negative feedback function of hyperbaric oxygen remained normal, the level of GCS showed a significant increase, which may be attributed to the adrenal cortex. Experiments have shown that chronic stress does not lead to increased sensitivity of the adrenal cortex to ACTH, suggesting that elevated levels of GCS may be associated with Other factors, such as adrenal hyperplasia and hypertrophy, leading to GCS secreted by ACTH stimulation. The increase in the amount of ̈6|. At the end of the experiment, the anatomy of the rats also found that the volume of the adrenal gland in the hyperbaric oxygen treatment group was significantly larger than that in the blank control group, but this experiment did not continue to infer the quality and pathological observation of the adrenal gland. Where. The nitric oxide system, especially the vascular nitric oxide system, is impaired in the body mainly as endothelial-mediated vasodilation disorder, which reduces the self-regulation ability of blood vessels in blood pressure changes, which indirectly promotes the appearance of endothelial damage. Endothelial damage combined with a variety of factors ultimately leads to the formation of atherosclerosis ̈7|. The increase of circulating inflammatory factors is one of the direct pathways of chronic stress, which is manifested by an increase in circulating IL-1, IL-6, TNF-d, etc. The increase of such inflammatory factors can cause bradykinin-mediated blood vessels. Diastolic dysfunction, mRNA expression and protein content of vascular nitric oxide synthase (eNOS), and finally increased H:O: expression, mediated oxidative stress ̈8|. Therefore, the effect of chronic stress on the nitric oxide system is mainly due to the role of pro-inflammatory factors. Therefore, this experiment attempts to utilize the nitric oxide system and the pro-inflammatory factor TNF. The observation of Ot evaluated the extent of stress impairment in hyperbaric oxygen therapy. This experiment observed that hyperbaric oxygen is a source of stress. However, there was no significant difference in the content of NOS and NO compared with the blank group. It is suggested that hyperbaric oxygen treatment may not affect the endothelial NO system in rats. In addition, TNF, one of the causes of chronic stress in the hyperbaric oxygen group, was only lower than that of the blank group. Although it was not statistically significant, there was a clear trend, suggesting that hyperbaric oxygen may reduce the synthesis of circulating pro-inflammatory factors. Among them, the parasympathetic nerve antagonized with sympathetic nerve is considered to be antagonized by sympathetic-mediated energy distribution and systemic inflammatory response, and in order to ensure the intensity of acquired immunity, its activity is often inhibited during inflammation. 019], while hyperbaric oxygen therapy One of the characteristics is the increased excitability of parasympathetic nerves. Therefore, this experiment speculates that the decrease of TNF-a may be caused by the excitability of parasympathetic nerves, and its anti-inflammatory effect is used to promote the decrease of circulating pro-inflammatory factors, but the above inference still needs further experimental proof. In summary, this experiment from the perspective of stress, observed that continuous hyperbaric oxygen treatment has the general characteristics of chronic stress, such as the improvement of circulating GCS; but on the other hand it is not as obvious as the general chronic stress Increase the degree of anxiety of the body, and at the same time, it may also inhibit the production of inflammatory factors and reduce TNF by increasing the activity of parasympathetic. 0 [even the expression of other pro-inflammatory factors to make the body resistant to damage caused by other stressors. Appropriate stress can strengthen the body's resistance to external stress. Ostrander et al (4) 1 found that rats in the chronic stress recovery period showed GCS, ACTH levels and decreased CRH mRNA in the paraventricular nucleus after receiving new types of stimulation. It shows that rats are adaptable to stress, so whether they can achieve effective adaptability, and there is no damage to the body between them may be the defining standard of benign stress. The preliminary observations in this experiment suggest that continuous hyperbaric oxygen therapy has the premise of benign stress for the body, that is, it may not cause excessive damage to the body or even reduce the damage of other stressors, but Whether it can be used as benign stress requires further verification of the experiment. Id Card,Id Card Reader,Id Card Tag,Smart Id Card Reader GRANDING TECHNOLOGY CO LTD , https://www.grandingsecurity.com